Keyword: radiation
Paper Title Other Keywords Page
MOPGW003 Collective Instability Studies for Sirius simulation, impedance, storage-ring, coupling 61
 
  • F.H. de Sá
    LNLS, Campinas, Brazil
 
  In this work we will present the estimates of single and multi-bunch instability thresholds and current-dependent effects, such as tune-shifts and potential-well distortion for the Sirius storage ring. The results were obtained by tracking simulations and semi-analytic methods using the updated and detailed impedance budget of the machine, which includes contributions from all the in-vacuum components and the coherent synchrotron radiation (CSR) impedance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW003  
About • paper received ※ 15 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW018 Perturbation of Synchrotron Motion in the Micro-Bunching Instability electron, bunching, synchrotron, storage-ring 108
 
  • T. Boltz, M. Brosi, E. Bründermann, B. Härer, A.-S. Müller, P. Schreiber, P. Schönfeldt, M. Yan
    KIT, Karlsruhe, Germany
 
  Short electron bunches in a storage ring are subject to complex longitudinal dynamics due to self-interaction with their own CSR. Above a particular threshold current, this leads to the formation of dynamically changing micro-structures within the bunch, generally known as the micro-bunching instability. The longitudinal dynamics of this phenomenon can be simulated by solving the Vlasov-Fokker-Planck equation, where the CSR self-interaction can be added as a perturbation to the Hamiltonian. This contribution particularly focuses on the comprehension of synchrotron motion in the micro-bunching instability and how it relates to the formation of the occurring micro-structures. Therefore, we adopt the perspective of a single particle and comment on its implications for collective motion. We explicitly show how the shape of the parallel plates CSR wake potential breaks homogeneity in longitudinal phase space and propose a quadrupole-like mode as potential seeding mechanism of the micro-bunching instability. The gained insights are verified using the passive particle tracking method of the Vlasov-Fokker-Planck solver Inovesa.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW018  
About • paper received ※ 15 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW029 Preliminary Study of Bunch Compression in the Hefei Light Source lattice, storage-ring, electron, synchrotron-radiation 151
 
  • W. Li, Z.H. Bai, W. Li, J.G. Wang, D.R. Xu, Z. Zhao
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  Funding: This work was supported by the Fundamental Research Funds for the Central Universities (Grant No.WK2310000082 and WK2310000077), and the National Natural Science Foundation of China(GrantNo.11475167).
Short electron bunch has interesting applications in the synchrotron radiation light sources, such as the production of powerful coherent THz radiation, time resolving spectrum analysis, etc. In this work, we are interested in acquiring the short bunch in the storage ring with a small circumference like Hefei Light Source. In this paper, we tried to approach the short bunch in two separate methods: by increasing the higher harmonic cavity voltage and by reducing the momentum compaction factor. The preliminary result and observations are shown and discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW029  
About • paper received ※ 16 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW041 Transverse Profile Shaping of a Charged-Particle Beam using Multipole Magnets - Formation of Hollow Beams - octupole, target, optics, multipole 184
 
  • Y. Yuri, T. Yuyama
    QST/Takasaki, Takasaki, Japan
  • M. Fukuda
    RCNP, Osaka, Japan
 
  The use of multipole magnets enables us to shape the transverse profile of a charged-particle beam into various ones that can never be realized through linear beam optics. To date, the formation of a large-area beam with a uniform transverse intensity distribution has been actually realized using octupole magnets in several accelerator facilities. In this presentation, we demonstrate the formation of different beam profiles using multipole magnets rather than existing rectangular uniform beams. Results of tracking simulations and beam-formation experiments will be shown on the formation of clear-cut beams with different cross-sectional shapes, depending on the order and strength of applied multipole magnets. The dynamic behavior of a beam focused with multipole magnets is also investigated theoretically to better understand the numerical and experimental results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW041  
About • paper received ※ 19 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW048 Design Study of an Electron Storage Ring for the Future Plan of Hiroshima Synchrotron Radiation Center. storage-ring, synchrotron, emittance, synchrotron-radiation 200
 
  • S. Matsuba, M. Katoh, K.S. Shimada
    HSRC, Higashi-Hiroshima, Japan
  • K. Harada
    KEK, Ibaraki, Japan
  • K. Kawase
    QST, Tokai, Japan
 
  Hiroshima synchrotron radiation center equips a 700 MeV electron storage ring nicknamed HiSOR. It has been operated for more than 20 years. The emittance of HiSOR is 400 nm, which is larger by one or more orders of magnitude than typical modern synchrotron light sources. Therefore, as the future plan of the facility, a new low emittance storage ring is desired. Several designs have been examined. In the newest version, we have selected the lattice structure similar to ASTRID 2 compact light source in Aarhus University, Denmark. The design goal is the energy of around 500 MeV, the circumference shorter than 50 m and the emittance smaller than 10 nm with straight sections for undulators more than 4. In this conference, we report the latest result from the design study.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW048  
About • paper received ※ 01 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW051 Diffusion Map Analysis in High Energy Storage Ring Based e+/e Collider dynamic-aperture, synchrotron-radiation, collider, synchrotron 203
 
  • J. Wu, Q. Qin, Y. Zhang
    IHEP, Beijing, People’s Republic of China
  • J. Wu, Y. Zhang
    University of Chinese Academy of Sciences, Beijing, People’s Republic of China
 
  Funding: Project 11775238 supported by NSFC
In a very high energy e+/e storage ring collider, e.g. Circular Electron Positron Collider (CEPC), the dynamic aperture is limited by the strong synchrotron radiation especially in the vertical direction. Some tracking results also shows that the beam lifetime does not correspond well to the dynamic aperture. Here we develop a method called diffusion map analysis, aiming to describe the beam distribution diffusion in transverse amplitude space by tracking less turns. The diffusion may come from quantum fluctuation of SR, beamstrahlung effect and nonlinearity. Comparing cases with different configuration of sextupoles, the diffusion map analysis presents good consistency with beam lifetime that needs much more turns of tracking. Constraints based on the diffusion map is applied to our dynamic aperture optimization, which could help us achieve enough long beam lifetime.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW051  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW059 Dynamic Aperture Limitation in e+ e Colliders due to Synchrotron Radiation in Quadrupoles quadrupole, synchrotron, betatron, synchrotron-radiation 221
 
  • A.V. Bogomyagkov, S.A. Glukhov, E.B. Levichev, S.V. Sinyatkin
    BINP SB RAS, Novosibirsk, Russia
 
  In a lepton storage ring of very high energy (e.g. in the e+e- Higgs factory) synchrotron radiation from quadrupoles constrains transverse dynamic aperture even in the absence of any magnetic nonlinearities. This was observed in tracking for LEP and the Future Circular e+e- Collider (FCC-ee). Synchrotron radiation in the quadrupoles modulates the particle energy at the double betatron frequency. Energy modulation varies transverse focusing strength at the same frequency and creates a parametric resonance of the betatron oscillations with unusual properties. It occurs at arbitrary betatron frequency and the magnitude of the parameter modulation of the betatron oscillation depends on the oscillation amplitude. Equilibrium between the radiation damping and the resonant excitation gives the boundary of the stable motion. Here we continue comparison of tracking results with analytical calculations of the parametric resonance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW059  
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW060 Cherenkov Radiation at Off-Axis Bunch Passage Through Dielectric Concentrator target, diagnostics, site, polarization 225
 
  • S.N. Galyamin, A.V. Tyukhtin, V.V. Vorobev
    Saint Petersburg State University, Saint Petersburg, Russia
 
  Funding: Work supported by the Grant from Russian Foundation for Basic Research (No. 17-52-04107).
Development of tunable systems for non-invasive bunch diagnostics is a modern trend in accelerator physics. Certain dielectric targets are considered in this context, for example, dielectric cones or prisms. Moreover, all-dielectric target which increase the radiated Cherenkov field near the predetermined focus up to several orders of magnitude has been described* and field near its focus and sensitivity of this target have been analyzed**. Here we consider a non-symmetrical case where charge trajectory has a shift with respect to structure axis. We develop analytical approach for description of Cherenkov radiation, perform three-dimensional simulations and compare the results.
* S.N. Galyamin and A.V. Tyukhtin, Phys. Rev. Lett., 113, 064802 (2014).
** S.N. Galyamin and A.V. Tyukhtin, Nucl. Instr. Meth. Phys. Res. B. 2017. V. 402. P.185-189.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW060  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW061 Radiation from a Dielectrically Loaded Waveguide with Open End GUI, vacuum, embedded, acceleration 228
 
  • S.N. Galyamin, A.A. Grigoreva, A.V. Tyukhtin, V.V. Vorobev
    Saint Petersburg State University, Saint Petersburg, Russia
  • A. Aryshev
    KEK, Ibaraki, Japan
 
  Funding: Work supported by Russian Science Foundation (Grant No. 18-72-10137).
Open-ended waveguide structures with dielectric loading excited by specially prepared electron bunches are considered as promising candidates for development of contemporary sources of Terahertz (THz) radiation. Despite of the fact that both ordinary vacuum THz devices (e.g., backward wave oscillator) are widely available and other mechanisms for THz generation are discussed, beam driven sources are still extremely attractive due to the extraordinary peak power of THz radiation*. In this report, we study electromagnetic (EM) field produced by a charged particle bunch exiting an open-ended circular waveguide with dielectric filling placed inside collinear vacuum waveguide of a larger radius. Based on the previously developed theory**, we mainly investigate Cherenkov radiation generated penetrated vacuum regions of the structure due to the diffraction mechanism. We pay attention to the case of a train of short bunches resulting in high-order Cherenkov modes excitation. We also develop analytical procedure allowing performing the limiting process to the case of infinite radius of the outer waveguide.
* B.D. O’Shea et al., Nature Communications, Vol. 7, P. 12763, (2016).
** S.N. Galyamin et al., J. Instrumentation, Vol. 13, P. C02012 (2018).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW061  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW062 Radiation of a Charge Moving in a Wire Structure FEL, simulation, lattice, electron 231
 
  • S.N. Galyamin, A.V. Tyukhtin, V.V. Vorobev
    Saint Petersburg State University, Saint Petersburg, Russia
  • A.I. Benediktovitch
    EuXFEL, Hamburg, Germany
  • A.I. Benediktovitch
    BSU, Minsk, Belarus, Belarus
 
  Funding: This work is supported by the grant from Russian Foundation for Basic Research (No. 17-52-04107).
In the X-ray frequency region, interaction of relativistic electrons with crystals results in parametric X-ray radiation (PXR), with its frequency being determined by distance between crystallographic planes and direction of electron motion. If instead of crystal one considers an artificial periodic structure with periods of the order of mm, one can expect emission of radiation of a similar nature at terahertz (THz) frequencies. This frequency range is of significant interest during last decade due to its prospective applications. Moreover, artificial wire-like structures are considered as a promising alternative to conventional dielectric structures for wakefield acceleration*. Here we consider electromagnetic (EM) field produced by a charged particle bunch moving through a lattice of parallel conducting wires. We present several approaches for analysis of EM field in the described wire structure. First, conventional two-wave approximation for describing the "short-wave response" is developed. Second, we use the effective medium approach and describe the "long-wave" part of the spectrum. Third, we develop a method based on vibrator antenna theory which can be useful for finite length wire structure.
* P.D. Hoang, et al., Phys. Rev. Lett., V. 120, P. 164801 (2018).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW062  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW064 On Wakefield in Dielectric Waveguide with Shallow Corrugation of Metallic Wall GUI, ECR, wakefield, impedance 237
 
  • A.V. Tyukhtin, E.R. Akhmatova, T.Yu. Alekhina, S.N. Galyamin, V.V. Vorobev
    Saint Petersburg State University, Saint Petersburg, Russia
 
  Funding: This work was supported by the Russian Science Foundation (Grant # 18-72-10137).
Bunch radiation in periodical waveguides was mainly analyzed for situations when wavelengths are comparable to the structure period (Smith-Purcell emission). However, it is also of interest to study the "long-wave radiation" with wavelengths which are much larger than the structure period*,**. In such situation, the exact boundary conditions on the complicated periodic surface can be replaced with the equivalent boundary conditions (EBC) which must be fulfilled on the smooth surface. Earlier we considered with this approach radiation of the bunch moving along the axis of circular vacuum corrugated waveguide**. Comparison of analytical results with COMSOL simulations showed high accuracy of the EBC method. Here we analyze an analogous problem for the waveguide with corrugated wall and dielectric filling under condition that Cherenkov effect takes place in the dielectric. Due to this fact the radiation differs radically from that in the vacuum waveguide. At the same time, the radiation has essential differences from the one in the usual dielectric waveguide. The radiation properties in the waveguide under consideration and its differences from the radiation in the waveguide with smooth wall are analyzed.
* G. Stupakov, K. Bane, Phys. Rev. ST-AB, 15 (2012) 124401.
** A.V. Tyukhtin et al, J. of Instrumentation, 13 (2018) C04009.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW064  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW100 Bypass Design for Testing Optical Stochastic Cooling at the Cornell Electron Storage Ring (CESR) optics, sextupole, wiggler, damping 360
 
  • W.F. Bergan, M.B. Andorf, M.P. Ehrlichman, V. Khachatryan, D. L. Rubin, S. Wang
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: NSF-1734189 DGE-1650441
Optical Stochastic Cooling (OSC) is a promising method for cooling very dense stored particle beams through the interference of radiation created in an upstream ’pickup’ wiggler and a downstream ’kicker’ wiggler. By correlating a particle’s path length via a bypass between the two wigglers with its betatron coordinates in the pickup, the particle will receive a kick in energy which, through coupling introduced by non-zero horizontal dispersion in the kicker, can reduce its betatron amplitude, thus cooling the beam. A proof-of-principle test of this technique is being planned at the Cornell Electron Storage Ring (CESR). In addition to maintaining standard requirements such as a large dynamic aperture and acceptable lattice functions throughout the ring, the design of the bypass is guided by the mutually competing goals of maximizing the cooling rate while maintaining a sufficiently large cooling acceptance with properly-corrected nonlinearities. We present a design of such a bypass and ring optics so as to best achieve these objectives.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW100  
About • paper received ※ 14 May 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW116 Validation of a Novel Method for the Calculation of Near-Field Synchrotron Radiation electron, acceleration, cyclotron, synchrotron 397
 
  • F.Y. Li, B.E. Carlsten, R. Garimella, C. Huang, T.J. Kwan
    LANL, Los Alamos, New Mexico, USA
 
  Funding: Work supported by the LDRD program at LANL.
The phenomenon of synchrotron radiation (SR) from electrons is at the core of modern accelerator based light sources. While SR in the far field has been well characterized, the near-field SR and its impacts on self-consistent electron beam dynamics remain an ongoing topic. Since it is difficult to experimentally characterize the near fields, it is desirable to develop accurate and efficient numerical methods for the design of these light sources. Here, we investigate a novel method, originally proposed by Shintake and which potentially has both high efficiency and accuracy. We focus on the field calculation of this method and show that the original idea has missed the important terms of fields due to electron acceleration and therefore only applies to a linear motion. To correct this limitation we developed a modified algorithm that gives consistent fields with direct calculations using the Liénard-Wiechert equation. Some basic signatures of the near-field SR fields are also drawn for a cyclotron motion by using this modified approach.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW116  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPGW124 Coherent Synchrotron Radiation Simulation for CBETA simulation, linac, lattice, shielding 406
 
  • W. Lou, C.M. Gulliford, G.H. Hoffstaetter, D. Sagan
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • C.E. Mayes
    SLAC, Menlo Park, California, USA
  • N. Tsoupas
    BNL, Upton, Long Island, New York, USA
 
  CBETA is an energy recovery linac accelerating from 6 MeV to 150 MeV in four linac passes, using a single return beamline accepting all energies from 42 to 150 MeV. While CBETA gives promise to deliver unprecedentedly high beam current with simultaneously small emittance, Coherent Synchrotron Radiation (CSR) can pose detrimental effect on the beam at high bunch charges and short bunch lengths. To investigate the CSR effects on CBETA, we used the established simulation code Bmad to track a bunch with different parameters. We found that CSR causes phase space dilution, and the effect becomes more significant as the bunch charge and recirculation pass increase. Potential ways to mitigate the effect involving vacuum chamber shielding and increasing bunch length are being investigated.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW124  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMP013 New Nuclotron Beam Lines and Stations for Applied Researches target, dipole, heavy-ion, diagnostics 449
 
  • E. Syresin, A.A. Baldin, A.V. Butenko, G.A. Filatov, A.A. Slivin, G.N. Timoshenko, G.V. Trubnikov, A. Tuzikov
    JINR, Dubna, Moscow Region, Russia
  • D.V. Bobrovskiy, A.I. Chumakov
    MEPhI, Moscow, Russia
  • M.M. Kats, T. Kulevoy, D.A. Liakin, Y.E. Titarenko
    ITEP, Moscow, Russia
 
  New beamlines for applied researches on the Nuclotron are under development within the framework of implementation of the NICA accelerator facility. Ion beams with energies of 150-800 MeV/n extracted from the Nuclotron will be used for radiobiological researches and modeling of cosmic rays interactions with microchips. Equipment of two experimental stations is under development by the JINR-ITEP-MEPhi collaboration for these applied researches. Ion beams with the energy of 3.2 MeV/n extracted from the heavy ion linac HILAc will also be used for irradiation and testing of microchips. The specialized channel will be reconstructed for investigations in the field of relativistic nuclear power at light ion energies of 0.3-4.5 GeV/n. Three new experimental areas are organized for applied physics researches within the framework of implementation of the NICA accelerator facility.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP013  
About • paper received ※ 29 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPMP035 Effect of Emittance Constraints on Monochromatization at the Future  Circular e+e Collider emittance, luminosity, collider, photon 516
 
  • M.A. Valdivia García, F. Zimmermann
    CERN, Meyrin, Switzerland
 
  Direct s-channel Higgs production in e+e− collisions is of interest if the collision energy spread can be comparable to the natural width of the standard model Higgs boson. At the Future Circular e+e Collider (FCC-ee), a monochromatization scheme could be employed in order to reduce the collision energy spread to the target value. This may be achieved by introducing a non-zero horizontal dispersion of opposite sign for the two colliding beams at the interaction point. In this case, the beamstrahlung increases the horizontal emittance in addition to energy spread and bunch length.  The vertical emittance could either be tuned to a certain minimum value, possibly limited by the diagnostics resolution, or it could scale linearly with the horizontal emittance. For the FCC-ee at 62.5 GeV beam energy, we optimize the IP optics and beam parameters, considering these two different assumptions for the vertical emittance. We derive the maximum achievable luminosity as a function of collision energy spread for either case.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP035  
About • paper received ※ 16 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPRB036 Study on Beam-induced heating in injection section of Hefei Light Source impedance, vacuum, kicker, experiment 652
 
  • D.R. Xu, W. Xu
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  Ceramic chambers distributed with metal belts on the inner surface are installed in the injection section at Hefei Light Source (HLS). Heating on the ceramics chambers has been observed during machine operation. An air compressor is used to cool these chambers due to concerns of overheating during top-up operation mode. To understand the sources of the heating, a series of experiments are performed with various beam currents and bunch filling patterns. The study shows that the heating is mainly caused by the narrow-band impedances of the ceramic chambers and their adjacent vacuum components.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB036  
About • paper received ※ 22 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPRB061 Simulations and Measurements of Coherent Synchrotron Radiation at the MAX-IV Short Pulse Facility detector, simulation, electron, dipole 712
 
  • B.S. Kyle
    University of Manchester, Manchester, United Kingdom
  • R.B. Appleby
    UMAN, Manchester, United Kingdom
  • M. Brandin, E. Mansten, S. Thorin
    MAX IV Laboratory, Lund University, Lund, Sweden
  • T.H. Pacey
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • P.H. Williams
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • J. Wolfenden
    The University of Liverpool, Liverpool, United Kingdom
 
  The Coherent Synchrotron Radiation (CSR) interaction is a source of unwanted correlated energy spread in short-bunch Free-Electron Lasers (FEL), diluting the desired FEL spectrum and reducing the total brightness of the light source. Many accelerator codes make use of 1-dimensional approximations in the calculation of the CSR-wake, which breaks down for bunch dimensions typical within bunch compressor dipoles in FELs. General Particle Tracer simulations of the CSR interaction make use of the 3-dimensional bunch distribution, making it advantageous in modelling the short-bunch, high aspect ratio regimes typical of modern 4th-generation light sources. Measurements of THz CSR emitted from the final bunch compressor dipole of the SP02 beamline at the MAX-IV Short Pulse Facility (SPF) were used, alongside start-to-end GPT and Elegant simulations, to characterize coherent radiation emission across a broad range of bunch lengths.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB061  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPRB075 Radiation Limits on Permanent Magnets in CBETA electron, vacuum, permanent-magnet, focusing 745
 
  • V.O. Kostroun, C.M. Gulliford
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  The Cornell Brookhaven Energy Recovery Linac Test Accelerator (CBETA), under construction at Cornell, uses Fixed Field Alternating Gradient (FFAG) Halbach magnets made from grade N35EH NdFeB. To reduce the 1% level magnetization errors in fabricated blocks to magnets with better than 0.001 field accuracy, iron wire shimming is necessary. This also limits magnetization changes by external influences to the ~1% level. The ambient radiation field present during CBETA operation can induce permanent magnet demagnetization. The radiation field arises from electrons in the beam halo hitting the vacuum chamber and from residual gas, Touschek and Intra-Beam scattering. The radiation dose rate due to electrons striking the vacuum chamber of a 4 cell straight section of CBETA FFAG magnets was calculated using the many particle Monte Carlo radiation code MCNP6.2. MCNP6.2 has a track-length heating tally for different particles and a collision heating tally that gives energy deposition/mass from all particles in the problem. Calculations show that electron loss has to be a fraction of a watt/m to keep the dose rate at an acceptable level during the accelerator lifetime.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB075  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPRB088 Study of Fluctuations in Undulator Radiation in the IOTA Ring at Fermilab experiment, undulator, electron, photon 777
 
  • I. Lobach
    University of Chicago, Chicago, Illinois, USA
  • A. Halavanau, Z. Huang, V. Yakimenko
    SLAC, Menlo Park, California, USA
  • K. Kim
    ANL, Argonne, Illinois, USA
  • V.A. Lebedev, S. Nagaitsev, A.L. Romanov, G. Stancari, A. Valishev
    Fermilab, Batavia, Illinois, USA
  • A.Y. Murokh
    RadiaBeam, Los Angeles, California, USA
  • T.V. Shaftan
    BNL, Upton, Long Island, New York, USA
 
  We study turn-by-turn fluctuations in the number of emitted photons in an undulator, installed in the IOTA electron storage ring at Fermilab with an InGaAs PIN photodiode and an integrating circuit. Our study was motivated by the previous experiment *. We propose a theoretical model for the experimental data from * and in our own experiment we attempted to verify the model in an independent and more systematic way. Moreover, these fluctuations are an interesting subject for a study by itself, since they act as a seed for SASE in FELs. We improve the precision of the measurements from * by subtracting the average signal amplitude using a comb filter with a one-turn IOTA delay, and by using a special algorithm for noise subtraction. We obtain a reasonable agreement between our theoretical model and experiment. Along with repeating the experiment from *, which was performed at a constant beam current, we also collect data for fluctuations in undulator light at different beam current values. Lastly, in our experiment we were able to see the transition from Poisson statistics to Super-Poisson statistics for undulator light, whereas in * only the latter statistics was observed.
* M. Teich et al., PRL, vol. 65, no. 27, p. 3393 (1990).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB088  
About • paper received ※ 14 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPRB089 Experimental Study of a Single Electron in a Storage Ring via Undulator Radiation photon, electron, undulator, experiment 781
 
  • S. Nagaitsev, A.L. Romanov, G. Stancari
    Fermilab, Batavia, Illinois, USA
  • A. Arodzero, A.Y. Murokh, M. Ruelas
    RadiaBeam, Santa Monica, California, USA
  • I. Lobach
    University of Chicago, Chicago, Illinois, USA
  • T.V. Shaftan
    BNL, Upton, Long Island, New York, USA
 
  A single electron orbiting around a ring and emitting single quanta at the rate of about one event per hundred turns could produce a wealth of information about physical processes in large traps (i.e. storage rings) for charged particles. It should be noted that Paul and Penning traps in the 1980s led to the Nobel prize for studying state and motion of single quantum particles, and just recently the Penning trap technique has enabled the measurement of a single proton magnetic moment with an unprecedented precision of 10 decimal places. The information from the storage ring traps could also be used for characterization of a quantum system as well as the "trap" itself, i.e. measuring properties of the storage ring lattice and electron interaction with the laser fields. Although, the interest in single electron quantum processes today is mostly academic in nature, the diagnostics and methodology developed for single electron radiation studies could find subsequent applications in a variety of applied disciplines in quantum technology, including quantum communications and quantum computing.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB089  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPRB093 eRHIC Electron Ring Design Status polarization, electron, storage-ring, solenoid 794
 
  • C. Montag, M. Blaskiewicz, C. Hetzel, D. Holmes, Y. Li, H. Lovelace III, V. Ptitsyn, K.S. Smith, S. Tepikian, F.J. Willeke, H. Witte, W. Xu
    BNL, Upton, Long Island, New York, USA
  • E. Gianfelice-Wendt
    Fermilab, Batavia, Illinois, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
For the proposed electron-ion collider eRHIC, an electron storage ring will be installed in the existing RHIC tunnel. To reach the high luminosity of up to 1034 cm-2 sec-1, beam currents up to 2.5A have to be stored. Besides high luminosity the physics program requires spin polarization levels of 70 percent, with both spin "up" and spin "down" orientations present in the fill. This is only feasible by using a full-energy spin polarized injector that replaces bunches faster than the depolarization rate. To limit the repetition rate of that injector to about one hertz, the polarization lifetime in the storage ring has to be maximized by proper spin matching and countermeasures for the machine misalignments. We will give an overview of the electron storage ring design.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB093  
About • paper received ※ 13 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPTS047 Radiation Measurement in the 1st Beam Commissioning Campaign of the LIPAc RFQ rfq, neutron, proton, MMI 964
 
  • K. Kondo, S. Kwon, K. Sakamoto, T. Shinya, M. Sugimoto
    QST, Aomori, Japan
  • L. Bellan, F. Grespan, F. Scantamburlo
    INFN/LNL, Legnaro (PD), Italy
  • P. Cara
    IFMIF/EVEDA, Rokkasho, Japan
  • H. Dzitko
    F4E, Germany
  • R. Heidinger
    Fusion for Energy, Garching, Germany
  • I. Podadera
    CIEMAT, Madrid, Spain
 
  The 1st proton beam acceleration of the Linear IFMIF Prototype Accelerator (LIPAc) through its novel RFQ was succeeded on 13th June 2018. Addition to plenty of beam diagnostics equipped in the beam line, we prepared some radiation detectors placed around the accelerator in order to acquire supplemental information of the beam, as an indirect measurement. In the first day of the beam injec-tion to the RFQ, the gamma-rays corresponding to certain excited states of Al of the low power beam dump were successfully detected by a LaBr3(Ce) scintillation detec-tor. Some neutrons, which would originate from the inter-action of protons with Cu somewhere, were also ob-served. These results proved that the beam was certainly accelerated up to about 2.5 MeV, and provided us a defin-itive confidence that the RFQ was working appropriately from the very beginning of the commissioning. Also, the comparison of the radiation yields with the RFQ trans-mission provided additional information on the beam energy distribution.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS047  
About • paper received ※ 23 May 2019       paper accepted ※ 24 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPTS054 Status of the CLEAR Electron Beam User Facility at CERN experiment, electron, plasma, operation 983
 
  • K.N. Sjobak, E. Adli, C.A. Lindstrøm
    University of Oslo, Oslo, Norway
  • M. Bergamaschi, S. Burger, R. Corsini, A. Curcio, S. Curt, S. Döbert, W. Farabolini, D. Gamba, L. Garolfi, A. Gilardi, I. Gorgisyan, E. Granados, H. Guerin, R. Kieffer, M. Krupa, T. Lefèvre, S. Mazzoni, G. McMonagle, N. Nadenau, H. Panuganti, S. Pitman, V. Rude, A. Schlogelhofer, P.K. Skowroński, M. Wendt, A. P. Zemanek
    CERN, Geneva, Switzerland
  • A. Lyapin
    UCL, London, United Kingdom
 
  The CERN Linear Electron Accelerator for Research (CLEAR) has now finished its second year of operation, providing a testbed for new accelerator technologies and a versatile radiation source. Hosting a varied experimental program, this beamline provides a flexible test facility for users both internal and external to CERN, as well as being an excellent accelerator physics training ground. The energy can be varied between 60 and 220 MeV, bunch length between 1 and 4 ps, bunch charge in the range 10 pC to 2 nC, and number of bunches in the range 1 to 200, at a repetition rate of 0.8 to 10 Hz. The status of the facility with an overview of the recent experimental results is presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS054  
About • paper received ※ 12 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPTS091 Mechanical Robustness of HL-LHC Collimator Designs experiment, site, proton, interface 1070
 
  • F. Carra, A. Bertarelli, G. Gobbi, J. Guardia, M. Guinchard, F.J. Harden, M. Pasquali, S. Redaelli, E. Skordis
    CERN, Meyrin, Switzerland
 
  Funding: This work has received funding from the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement No. 730871. Research supported by the HL-LHC project.
Two new absorbing materials were developed as collimator inserts to fulfil the requirements of HL-LHC higher brightness beams: molybdenum-carbide graphite (MoGr) and copper-diamond (CuCD). These materials were tested under intense beam impacts at CERN HiRadMat facility in 2015, when full jaw prototypes were irradiated. Additional tests in HiRadMat were performed in 2017 on another series of material samples, including also improved grades of MoGr and CuCD, and different coating solutions. This paper summarizes the main results of the two experiments, with a main focus on the behaviour of the novel composite blocks, the metallic housing, as well as the cooling circuit. The experimental campaign confirmed the final choice for the materials and the design solutions for HL-LHC collimators, and constituted a unique chance of benchmarking numerical models. In particular, the tests validated the selection of MoGr for primary and secondary collimators, and CuCD as a valid solution for robust tertiary collimators.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS091  
About • paper received ※ 12 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPTS092 Numerical and Experimental Evaluation of the DQW Crab Cavity Cryomodule Thermal Budget cryomodule, cavity, HOM, experiment 1074
 
  • F. Carra, K. Brodzinski, E. Cano-Pleite, O. Capatina
    CERN, Meyrin, Switzerland
 
  Funding: Research supported by the HL-LHC project
One of the key devices of the HL-LHC project are SRF Crab Cavities. A cryomodule with two Double Quarter Wave (DQW) crab cavities has been fabricated at CERN in 2017 and successfully tested with beam in the Super Proton Synchrotron (SPS) in 2018. The aim of the present study is to present and compare the estimation of the thermal budget for the different components of the cryomodule, performed with numerical and semi-analytical methods, with the experimental measurements carried out on the cryomodule after installation in the SPS.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS092  
About • paper received ※ 12 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPTS105 The High Brightness Photo-injector for THz CUR/VUV FEL at NSRRC electron, emittance, quadrupole, linac 1125
 
  • A.P. Lee, M.C. Chou, H.P. Hsueh, J.-Y. Hwang, W.K. Lau
    NSRRC, Hsinchu, Taiwan
  • P. Wang
    NTHU, Hsinchu, Taiwan
 
  A high brightness photo-injector has been build for THz coherent undulator radiation and VUV free electron laser test facility at NSRRC. In the first phase, the photo-injector was used to produce ultra-short electron bunches for THz CUR generation. The electron beam is generated form a photocathode rf gun followed by a solenoid for emittance compensation. Then A 5.2 m S-band linac accelerates the electron beam and compresses the beam by velocity bunching. Since the beam emittance will grow during the velocity bunching process, a solenoid system was installed to reduce the emmitance growth. Downstream the linac, a quadruple magnet was use for emittance measurement by quadruple scan method and the bunch length was measured by the coherent transition radiation. Finally, the ultra-short electron bunch with about few hundreds picoseconds passes through a U100 planer undulator can produce THz coherent undulator radiation. The instrument setup and results of measurement are presented in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS105  
About • paper received ※ 14 May 2019       paper accepted ※ 17 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOPTS110 FLUKA-MARS15 Simulations To Optimize the Fermilab PIP-II Movable Beam Absorber linac, MMI, shielding, simulation 1136
 
  • L. Lari, F.G. Garcia, Y. He, I. Kourbanis, N.V. Mokhov, E. Pozdeyev, I.L. Rakhno
    Fermilab, Batavia, Illinois, USA
  • F. Cerutti, L.S. Esposito, L. Lari
    CERN, Meyrin, Switzerland
 
  PIP-II is the Fermilab’s flagship project to provide powerful, high-intensity proton beams to the laboratory’s experiments. The heart of the PIP-II project is an H 800 MeV superconducting linear accelerator. In order to commission the beam and operate safely the linac, several constraints were evaluated. The design of a movable 5 kW beam absorber was finalized to allow staged beam commissioning in different linac locations. Prompt and residual radiation levels were calculated, and radiation shields were optimized to keep those values within the acceptable levels in the areas surrounding beam absorber. Monte Carlo calculations with FLUKA and MARS15 codes are presented in the paper to support these studies.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS110  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUZZPLS3 New Method of Calculation of the Wake due to Radiation and Space Charge Forces in Relativistic Beams wakefield, electron, space-charge, synchrotron-radiation 1223
 
  • G. Stupakov
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by the Department of Energy, Contract No. DE-AC02-76SF00515.
Radiation reaction force in a relativistic beam, also known as a CSR wakefield, is often computed using a 1D model of a line charge beam. While this model can serve as a useful tool for a quick calculation, in some cases, it may not be sufficiently accurate. In particular, this model misses the so-called compression effects associated with the change of the electromagnetic energy when the beam is compressed longitudinally or transversely. The existing 3D simulation codes that take this effect into account are often slow and are not easy to use. In this work, we propose a new approach to the calculations of radiation and space charge longitudinal forces based on the use of the integrals for the retarded potentials. Our main result expresses the rate of change of particles energy through 2D (in a 2D model) or 3D integrals for a given orbit of the beam. It generalizes the 1D model and includes the transient effects of at the entrance and the exit from the magnet. For a given beam line with known magnetic lattice, and a known distribution function of the beam, the calculation reduces to taking 2D or 3D integrals along the orbit.
 
slides icon Slides TUZZPLS3 [2.080 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUZZPLS3  
About • paper received ※ 29 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMP013 New Design of Vacuum Chambers for Radiation Shield Installation at Beam Injection Area of J-PARC RCS vacuum, injection, damping, flattop 1255
 
  • J. Kamiya, K. Kotoku, Y. Shobuda, T. Takayanagi, K. Yamamoto, T. Yanagibashi
    JAEA/J-PARC, Tokai-mura, Japan
  • K. Horino, N. Miki
    Nippon Advanced Technology Co., Ltd., Tokai, Japan
 
  One of the issues in the J-PARC 3 GeV rapid cycling synchrotron is the high residual radiation dose around the beam injection point. A radiation shield is necessary to reduce radiation exposure of workers when maintenance is performed there. A space to install the radiation shield should be secured by newly designing a structure of the vacuum chamber at the injection point and the alumina ceramics beam pipes for the shift bump magnets. To make the space for the shield, the chamber is lengthened along the beam line and the cross-sectional shape is changed from circle to rectangle. The displacement and inner stress of the vacuum chamber due to atmospheric pressure was evaluated to be enough small by the calculation. For the ceramics beam pipe’s rf-shield, the damping resistor was effective to reduce the induced modulation voltages by the pulsed magnetic field.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP013  
About • paper received ※ 29 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMP022 Research on Digital Scanning Power Supply Technology for Proton Therapy System power-supply, proton, controls, scattering 1286
 
  • J. Huang, M. Fan, J. Yang, L.G. Zhang
    HUST, Wuhan, People’s Republic of China
  • T. Yu, C. Zuo
    Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People’s Republic of China
 
  Funding: Work supported by The National Key Research and Development Program of China, with grant No. 11505068
Proton has great advantages in the field of cancer radiotherapy because of its good characteristic of Bragg peak. HUST-PTF is a proton therapy facility under development in Huazhong University of science and technology. It delivers the beam to the patients with a pencil beam scanning nozzle. Scanning power supplies are placed in the nozzle of the proton therapy device and they are required high accuracy, high speed and high stability. In this paper,the structure diagram of HUST-PTF is shown. The parameters of scanning magnets and its power supply are introduced. Finally, some test results of power supply are shown. The next work will debug the control system of the scanning power supply and adjust it with the scanning magnet to see if it meets the design requirements.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP022  
About • paper received ※ 19 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMP025 Design of Fast Corrector Magnet Power Supply for HEPS power-supply, controls, simulation, experiment 1294
 
  • P. Liu, C. Han, F. Long
    IHEP, Beijing, People’s Republic of China
 
  High energy photon source is a fourth-generation synchrotron radiation light source with energy of 6Gev and ultra-low emittance (<0.1nm’rad). The ultra-low beam emittance requires high beam stability. Therefore, we develop a fast correction power supply with high bandwidth and low current ripple to improve the performance of the fast close orbit correction sys-tem to prove the high beam stability. The power supply adopts FPGA for full-digital control and use high speed ADC with temperature control. The power sup-ply has a small signal-bandwidth of 10 kHz and output current ripple lower than 20ppm. In this paper, we will describe the hardware design and software control methods and the test results will be demonstrated  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP025  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMP036 Results on the FCC-hh Beam Screen Sawtooth at the Kit Electron Storage Ring Kararesults on the Fcc-Hh Beam Screen Sawtooth at the Kit Electron Storage Ring Kara photon, vacuum, experiment, electron 1323
 
  • L.A. Gonzalez, V. Baglin, I. Bellafont, P. Chiggiato, C. Garion, R. Kersevan
    CERN, Geneva, Switzerland
  • I. Bellafont, F. Pérez
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  • S. Casalbuoni, E. Huttel
    KIT, Eggenstein-Leopoldshafen, Germany
 
  Funding: * The European Circular Energy-Frontier Collider Study (EuroCirCol) project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant No 654305.
In the framework of the EuroCirCol collaboration (work package 4 "Cryogenic Beam Vacuum System"), the fabrication of the FCC-hh beam screen (BS) prototype has been carried out with the aim of testing it at room temperature on the Karlsruhe Institute of Technology (KIT) 2.5 GeV electron storage ring KARA (KArlsruhe Research Accelerator) light source. The BS prototype was tested on a beamline installed by the collaboration, named as BEam Screen TEstbench EXperiment (BESTEX). KARA has been chosen because its synchrotron radiation (SR) spectrum, photon flux and power match quite well the one foreseen for the 50+50 TeV FCC-hh proton collider. The BS prototype (2 m in length) was manufactured according to the base line design (BD) of the FCC-hh BS. It implements a saw-tooth profile designed to absorb the SR generated at the bending magnets. Also, a laser-ablated anti-electron cloud surface texturing [2] was applied at the BS inner walls. We present here the results obtained at BESTEX and the comparison of the results obtained during irradiation of the saw-tooth profile at different geometric configurations.
This activity has been carried out in the framework of the EuroCirCol* collaboration (work package 4 "Cryogenic Beam Vacuum System").
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP036  
About • paper received ※ 13 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMP042 The Beam Cleaning Analysis for the TPS Vacuum System vacuum, MMI, operation, ECR 1344
 
  • Y.C. Yang, C.K. Chan, C.-C. Chang, A.Y. Chen, J.-Y. Chuang, C.H. Huang
    NSRRC, Hsinchu, Taiwan
 
  Commissioning for the TPS, a low-emittance 3-GeV synchrotron ring, started in December 2014 and is now currently operating in top-up mode at 400mA for users. Until the last machine shut down in December 2018, a total beam dose of 4919 Ah was accumulated and the beam cleaning effect decreased the dynamic pressure to 1.5×10-11 Pa/mA. During past years operation, several vacuum chambers were replaced to improve vacuum performance and avoid exposure to synchrotron radiation from insertion devices. In this paper, the beam cleaning evolution of new vacuum sections will be discussed and compared with experience in the rest of the storage ring. A particular cleaning evolution could be predicted and can be referenced for machine shutdown planning in the future.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP042  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMP048 Current Status of Turkish Accelerator and Radiation Laboratory electron, cavity, FEL, status 1359
 
  • A.A. Aksoy, O.F. Elçim
    Ankara University Institute of Accelerator Technologies, Golbasi, Turkey
  • Ö. Karslı, C. Kaya, B. Koc
    Ankara University, Accelerator Technologies Institute, Golbasi, Turkey
 
  Funding: T.R. Presidency Strategy and Budget Office Grand No: 2006K-120470
Turkish Accelerator and Radiation Laboratory (TARLA) which is designed to deliver various accelerator based radiation sources, aims to be outstanding research instrument for users from both Turkey and region. Within the current scope of TARLA its superconducting accelerator will drive two of free electron laser (FEL) beamlines in order to provide Continuous Wave (CW) tunable radiation of high brightness in the mid- and far-infrared range as well as a Bremmstrahlung radiation station. Main components of TARLA, such as injector, superconducting accelerating modules and cryoplant are under commissioning currently. In this paper commissioning results and current status of facility are presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP048  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPGW006 Measurements of the Momentum Compaction Factor of the ESRF Storage Ring undulator, electron, SRF, synchrotron 1392
 
  • N. Carmignani, W. De Nolf, A. Franchi, C. Sahle, L. Torino
    ESRF, Grenoble, France
  • B. Nash
    RadiaSoft LLC, Boulder, Colorado, USA
 
  In a storage ring, the momentum compaction factor can be obtained by measuring the variation of the beam energy as a function of the RF frequency. In this paper we present the measurement of the momentum compaction factor from two different methods. With the first, we measure the variation of the undulator spectra for different RF frequencies. With the second, we measure the variation of the hard x-rays flux produced by a dipole for different RF frequencies.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW006  
About • paper received ※ 29 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPGW015 Petra III Operation and Studies 2018 operation, vacuum, impedance, undulator 1419
 
  • M. Bieler, I.V. Agapov, Y.-C. Chae, J. Keil, G.K. Sahoo, R. Wanzenberg
    DESY, Hamburg, Germany
 
  At DESY the Synchrotron Light Source PETRA III offers scientists outstanding opportunities for experiments with hard X-rays of exceptionally high brilliance since 2009. This paper describes the operational schedule, the operational statistics and the most important beam studies done at PETRA III in 2018.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW015  
About • paper received ※ 26 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPGW024 Pulse Shaping Methods for Laser-Induced Generation of THz Radiation at the Delta Storage Ring laser, electron, storage-ring, experiment 1453
 
  • C. Mai, B. Büsing, A. Glaßl, S. Khan, D. Krieg, A. Meyer auf der Heide
    DELTA, Dortmund, Germany
 
  At DELTA, a 1.5-GeV electron storage ring operated as a synchrotron light source by the TU Dortmund University, a dedicated beamline is used for experiments with (sub-)THz radiation. Here, an interaction of short laser pulses with electron bunches to give rise to coherently emitted broadband as well as tunable narrowband radiation from 75 GHz to 5.6 THz. For the narrowband operation of the source, a laser pulse with periodic intensity modulation is used. An interferometric approach, the chirped-pulse beating technique, is routinely employed for this purpose. Recently, pulse shaping techniques using spatial light modulators are investigated to gain more flexible control of the laser pulse shape and the spectrotemporal properties of the resulting THz pulses.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW024  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPGW025 The DELTA Short-Pulse Source: Upgrade Plans from CHG to EEHG laser, electron, undulator, optics 1457
 
  • A. Meyer auf der Heide, B. Büsing, S. Khan, D. Krieg, C. Mai, F. Teutenberg
    DELTA, Dortmund, Germany
 
  At the synchrotron light source DELTA operated by the TU Dortmund University, coherent harmonic generation (CHG) is employed to provide ultrashort pulses in the vacuum ultraviolet and terahertz (THz) regime. Here, a modulation of the electron energy induced by an interaction of an ultrashort laser pulse with an electron bunch is transformed into a density modulation by a magnetic chicane. This results in coherent emission at harmonics of the laser wavelength as well as THz radiation. With the planned upgrade towards echo-enabled harmonic generation (EEHG), much higher harmonics can be achieved by adding a second laser-electron interaction. The necessary major modifications of the DELTA storage ring and investigations of the laser-electron interaction will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW025  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPGW033 Status of Test-Accelerator as Coherent THz Source (t-ACTS) at ELPH, Tohoku University electron, undulator, polarization, FEM 1475
 
  • S. Kashiwagi, H. Hama, F. Hinode, K. Kanomata, S. Miura, N. M. Morita, T. Muto, I. Nagasawa, K. Nanbu, S. Ninomiya, H. Saito, K. Takahashi, H. Yamada
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
 
  A test-Accelerator as Coherent Terahertz Source (t-ACTS) has been under development at the Research Center for Electron Photon Science (ELPH), Tohoku University, in which an intense coherent terahertz radiation is generated from the femtosecond electron pulses. Velocity bunching scheme in a traveling accelerating structure is employed to generate femtosecond electron pulses, and the generation of femtosecond electron pulses was confirmed by spectrum analysis of coherent transition radiation using Michelson interferometer. Coherent transition radiation and coherent undulator radiation in the terahertz (THz) region from the short electron pulses has been demonstrated, and their characteristics such as frequency spectrum, spatial distribution and polarization were measured and compared with theoretical calculations. We have succeeded to generate the coherent transition radiation up to approximately 5 THz and the coherent undulator radiation with narrow bandwidth from 2.6 to 3.4 THz. At present, development of a variable polarized THz light source using a crossed-undulator system is being carried out. In addition, we are developing a nondestructive beam monitor using Cherenkov radiation emitted from the electron pulses. The status of t-ACTS will be presented in this conference.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW033  
About • paper received ※ 17 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPGW037 Systematic Measurements of the Coherent THz Spectra by Magnetic Bunch Compression at the Compact ERL optics, electron, sextupole, linac 1486
 
  • M. Shimada, Y. Honda, R. Kato, T. Miyajima, N. Nakamura, T. Obina, T. Uchiyama
    KEK, Ibaraki, Japan
  • T. Hotei
    Sokendai, Ibaraki, Japan
 
  Short electron bunch beam is one of the key elements of a Free Electron Laser (FEL) or intense THz coherent light source. The Energy Recovery Linac (ERL) has the strong advantage of operation of such an electron bunch at high repetition rate and is expected to increase the photon flux. At the Compact ERL in KEK site, we have demonstrated the magnetic bunch compression at the 180-degree return arc and measured the THz spectra of the Coherent Transition Radiation (CTR). This paper reports the revamped THz beamline and the improvement of the beam tuning as well as the systematic measurements of the THz spectra by magnetic bunch compression.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW037  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPGW038 Study on Coherent THz Radiation Using Tilt Control of Electron Beam electron, solenoid, target, experiment 1489
 
  • Y. Tadenuma, M. Brameld, T. Murakami, K. Sakaue, M. Washio
    Waseda University, Tokyo, Japan
 
  Funding: This work was supported by a research granted from JSPS KAKENHI 17H02821.
The terahertz wave is located in the intermediate frequency band between radio waves and light waves, and researches on the light sources such as terahertz quantum cascade laser and femtosecond laser based THz sources are being conducted*. As a new terahertz light source, we are studying coherent Cherenkov radiation by using the tilt control of electron beam and irradiating the target medium. Since the radiation intensity of Cherenkov radiation depends on the target medium, comparison of three kinds of medium with different refractive index and density, and optimization of the target shape were performed. In addition, we are going to try quasi monochromatization of radiation by using multi slit to control the form factor of the electron beam. In this presentation, we will report the experimental results of target optimization and quasi monochromatization and the future prospects.
*S. S. Dhillon, et al., The 2017 terahertz science and technology roadmap, J. Phys. D: Appl. Phys., 50 (2017) 043001.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW038  
About • paper received ※ 12 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPGW045 Lattice Design for the Reversible SSMB electron, emittance, storage-ring, bunching 1507
 
  • C.L. Li
    SINAP, Shanghai, People’s Republic of China
  • A. Chao
    SLAC, Menlo Park, California, USA
  • C. Feng, B.C. Jiang
    Shanghai Advanced Research Institute, Pudong, Shanghai, People’s Republic of China
 
  Steady State Microbunching (SSMB) aiming at producing high average power radiation in the electron storage ring has been proposed by Ratner and Chao years ago. Reversible seeding scheme is one of the promising scenarios with less challenges on the storage ring lattice design. The key problem for reversible SSMB is the precise cancelation of the laser modulation which will allow producing turn-by-turn coherent radiation without spoiling the transverse emittances and energy spread. In this paper the lattice design for the microbunching generation and its cancelation will be presented. Also a storage ring lattice design will be shown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW045  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPGW051 Generation of Two Terahertz Radiation Pulses with Continuously Tunable Frequency and Time Delay electron, laser, cathode, gun 1518
 
  • W.X. Wang, Z.G. He, S.M. Jiang, H.R. Zhang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  We propose to generate two narrow band terahertz pulses radiated from two temporally modulated relativistic electron beams, which are generated in a photo-injector. The temporal profile of the drive laser is modulated by means of the paired chirped pulses beating technique, leading to the generation of two pre-bunched electron beams. Coherent transient radiation (CTR) is considered as the mechanism for terahertz radiation generation. The frequencies of the two terahertz pulses can be independently tuned by adjusting the paired beating frequencies, and the interval between the two terahertz pulses can be adjusted by the optical delay line.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW051  
About • paper received ※ 30 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPGW068 New Source for Bending Magnet Beam Lines at Ultra-Low-Emittance Ring dipole, lattice, storage-ring, wiggler 1557
 
  • M. Abbaslou, M. Sedaghatizadeh
    KNTU, Tehran, Iran
  • S. Dastan, J. Rahighi, F. Saeidi
    ILSF, Tehran, Iran
 
  The Iranian Light Source Facility (ILSF) is a 3 GeV 3rd synchrotron radiation laboratory in the basic design phase. The Storage Ring (SR) is based on a five-bend achromat (5BA) lattice providing low horizontal emittance of 0.27 nm.rad. Due to the ILSF storage ring, straight section limits the use of the short length wigglers for hard X-ray generation is recommended. Which are removable in the lattice. In this article, the new design of the 3-pole wiggler is investigated and the main parameters of this 3-pole wiggler, by considering the ILSF storage ring characteristics, is modified. Also, the effect of the new 3-pole wiggler on the beam dynamics is investigated and the advantages of the new design are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW068  
About • paper received ※ 28 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB012 Design of High Power CW IR-THz Source for the Radiation Source ELBE Upgrade undulator, electron, FEL, linac 1702
 
  • P.E. Evtushenko, T.E. Cowan, U. Lehnert, P. Michel
    HZDR, Dresden, Germany
 
  The Radiation Source ELBE at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) is a user facility based on a 1 mA - 40 MeV CW SRF LINAC. Presently HZDR is considering upgrade options for the ELBE or its replacement with a new CW, SRF LINAC-based user facility. A part of the user requirements is the capability to generate IR and THz pulse in the frequency range from 0.1 through 30 THz, with pulse energies in the range from 100 uJ through a few mJ, at the repetition rate between 100 kHz and 1 MHz. This corresponds to the pulse energy increase, dependent on the wavelength by a factor from 100 through 1000. In this contribution, we outline key aspects of a concept, which would allow to achieve such parameters. Such key aspects are: 1 - use of a beam with longitudinal density modulation and bunching factor of about 0.5 at the fundamental frequency; 2 - achieving the density modulation through the mechanism similar to the one used in optical klystron (OK) and HGHG FEL; 3 - generating necessary for the modulation optical beam by an FEL oscillator, and 4 - using two electron injectors, where one injector provides beam for the FEL oscillator while second high charge injector provides beam for the high energy per pulse generation for user experiments. All-in-all the concept of the new radiation source is very similar to an OK, but operating with two beams simultaneously.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB012  
About • paper received ※ 21 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB021 Undulator Radiation Dose Caused by Synchrotron Radiation at the European XFEL undulator, FEL, simulation, vacuum 1724
 
  • S. Liu
    DESY, Hamburg, Germany
  • Y. Li, F. Wolff-Fabris
    EuXFEL, Hamburg, Germany
 
  Radiation damage of the undulators is a big concern for the light sources. At the European XFEL (EuXFEL), dosimeters based on on-line Radfets are used for the un-dulator radiation dose measurements. However, since the Radfets are not only sensitive to the electrons and neu-trons but also to the photons, it can capture the synchro-tron radiation (SR) generated in the undulators, which is not considered to be the main source for undulator radia-tion damage. Therefore, it is important to estimate the contribution of synchrotron radiation to the radiation doses measured by the Radfets. For this purpose, we have first calculated the synchrotron radiation profile using SPECTRA, and then put the profile into the tracking code BDSIM to track it through the whole undulator beam line. The radiation doses from SR have been simulated and compared with the measured values. The differences in the radiation doses measured by the Radfets before and after Pb shielding will also be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB021  
About • paper received ※ 30 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB022 Triple Period Undulator undulator, vacuum, photon, operation 1728
 
  • A. Meseck, J. Bahrdt, W. Frentrup, M. Huck, C. Kuhn, C. Rethfeldt, M. Scheer
    HZB, Berlin, Germany
  • E.C.M. Rial
    DLS, Oxfordshire, United Kingdom
 
  Insertion devices are one of the key components of modern synchrotron radiation facilities. They allow for generation of radiation with superior properties enabling experiments in a variety of disciplines, such as chemistry, biology, crystallography and physics to name a few. For future cutting edge experiments in soft and tender x-rays users require high flux and variable Polarization over a wide photon energy range independent of other desired properties like variable pulse length, variable timing or Fourier transform limited pulses. In this paper, we propose a novel ID-structure, called Triple Period Undulator (TPU), which allow us to deliver a wide energy range from a few ten eV to a few keV at the same beamline with high flux and variable Polarization. The TPU are particularly interesting in context of BESSY III, the successor facility of BESSY II.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB022  
About • paper received ※ 15 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB035 Stimulated Emission of THz Coherent Diffraction Radiation in an Optical Cavity by a Multibunch Electron Beam cavity, experiment, resonance, electron 1763
 
  • Y. Honda, A. Aryshev, R. Kato, T. Miyajima, T. Obina, M. Shimada, R. Takai, T. Uchiyama, N. Yamamoto
    KEK, Ibaraki, Japan
 
  Funding: JSPS KAKENHI
Accelerator-based terahertz (THz) radiation has been expected to realize a high-power broad-band source. Employing a low-emittance and short-bunch electron beam at a high repetition rate, a scheme to resonantly excite optical cavity modes of THz spectrum range via coherent diffraction radiation has been proposed. The confocal cavity design is the special case that resonance conditions of all the eigen modes coincide, resulting in realizing broad-band excitation. But in general cases of non-confocal cavities, the resonance condition depends on the mode, and the resonance peak becomes wide and weak. We performed an experiment with a non-confocal cavity as a follow-up experiment of that we have done with a confocal cavity. The result confirmed that the confocal design is the key for a broad-band source.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB035  
About • paper received ※ 26 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB037 Experimental Demonstration of Vector Beam Generation With Tandem Helical Undulators polarization, undulator, experiment, simulation 1766
 
  • S. Matsuba
    HSRC, Higashi-Hiroshima, Japan
  • M. Fujimoto, M. Katoh
    UVSOR, Okazaki, Japan
  • M. Hosaka
    Nagoya University, Nagoya, Japan
  • K. Kawase
    QST, Tokai, Japan
  • T. Konomi, N. Yamamoto
    KEK, Ibaraki, Japan
  • A. Miyamoto
    Toshiba, Yokohama, Japan
  • S. Sasaki
    ANL, Argonne, Illinois, USA
 
  Vector beam is a light beam with spatially modulated polarization state across the beam. Particular examples of vector beam are radial and azimuthal polarization which have donut-shaped intensity and radially and azimuthally oriented linear polarization state. Vector beam has long been interest in the laser community and it is well known that vector beam can be created by superposing two optical vortex beams which have spiral wave fronts. It has been demonstrated that optical vortex beam can be generated from a helical undulator as harmonics. Therefore, we propose a scheme to generate vector beam by superposing two optical vortex beams from two helical undulators in tandem, based on the principle of the ’crossed undulator’. The experiment was carried out at UVSOR BL1U. In this paper, we describe the principle and the experimental details.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB037  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB038 Characteristics of Polarized Coherent Radiation in Thz Region From a Crossed-Undulator undulator, polarization, experiment, electron 1769
 
  • H. Saito, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, N. M. Morita, T. Muto, I. Nagasawa, K. Nanbu, S. Ninomiya, K. Takahashi, H. Yamada
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
 
  A variable polarized THz light source using a crossed-undulator configuration has been developed at Research Center for Electron Photon Science (ELPH), Tohoku University. It consists of two planar undulators of which deflecting planes cross at right angles and a phase shifter for phase adjustment. Polarization of the crossed-undulator has observation angle dependence due to that of radiation wavelength and optical path length difference between two radiations. That limits an angular range maintaining the identical polarization state. Assuming undulator parameters for our experiment (a fundamental frequency 1.9 THz and a number of periods seven) degree of circular polarization larger than 0.9 can be obtained only in the range of 2.2 mrad, i. e. 13% of the radiation angular spread.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB038  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB039 Research of Coherent Edge Radiation Generated by Electron Beams Oscillating Free-Electron Lasers FEL, electron, cavity, experiment 1772
 
  • N. Sei, H. Ogawa
    AIST, Tsukuba, Ibaraki, Japan
  • K. Hayakawa, Y. Hayakawa, K. Nogami, T. Sakai, Y. Sumitomo, Y. Takahashi, T. Tanaka
    LEBRA, Funabashi, Japan
  • H. Ohgaki, H. Zen
    Kyoto University, Kyoto, Japan
 
  Funding: JSPS KAKENHI Grant Number JP16H03912
We have studied far-infrared coherent radiation with an S-band linac at Laboratory for Electron Beam Research and Application (LEBRA) at Nihon University. We have already developed a couple of terahertz-wave sources based on coherent synchrotron radiation and coherent transition radiation*, which have been applied to spectroscopic research**. Moreover, we developed coherent edge radiation (CER) at the downstream bending magnets in the FEL sections. Because the edge radiation has an annular shape distribution characterized by the asymmetric first-order Laguerre-Gaussian mode, the CER can be extracted from an optical cavity of the FEL system without a diffraction loss of the FEL beam***. The root-mean-squared bunch length of the electron beam was evaulated by measuring the CER spectra, which was about the same level as the FEL micropulse width. Although the infrared FELs at LEBRA had a long slippage length, the CER intensity can be a guidepost enhancing the FEL power because of the existence of their correlation. In this presentation, the characteristics of the CER including correlation between the CER and the FEL will be reported.
* N. Sei et al., Jpn. J. Appl. Phys. 56, (2017) 032401.
** N. Sei et al., J. Opt. Soc. Am. B, 31, (2014) 2150.
*** N. Sei et al., Phys. Lett. A in press.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB039  
About • paper received ※ 19 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB040 Development of Coherent Terahertz Wave Sources and Transport Systems at LEBRA Linac FEL, linac, electron, vacuum 1775
 
  • T. Sakai, K. Hayakawa, Y. Hayakawa, K. Nogami, Y. Sumitomo, T. Tanaka
    LEBRA, Funabashi, Japan
  • H. Ogawa, N. Sei
    AIST, Tsukuba, Ibaraki, Japan
 
  Funding: This work was supported by JSPS KAKENHI (Grant-in-Aid for Young Scientists (B)) Grant Number JP16K17539 and JP16H03912.
Development of a 125 MeV S-band electron linac for the generation of Free Electron Laser (FEL), Parametric X-ray Radiation (PXR) and coherent terahertz waves (THz waves) has been underway at LEBRA of Nihon University as a joint research with KEK and National Institute of Advanced Industrial Science and Technology (AIST). The high power coherent transition radiation (CTR), coherent edge radiation (CER) and the coherent synchrotron radiation (CSR) wave sources development has been carried out since 2011 at LEBRA. The transport systems of the each THz wave were installed in the vacuum chamber on the downstream side of the 45 degrees bending magnet of the PXR and FEL beam-line. In particular, a CER of the generated the FEL beam line can also be guided without disturbing the FEL oscillations. Additionally, a part of the mirror of the transport optical system is constructed using Indium Tin Oxide (ITO) mirror with the optimized for the transport of the THz wave. In this report, construction of the THz transport beam lines and the property of the THz lights are discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB040  
About • paper received ※ 19 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB041 Simulation of Short-Pulse Generation from a Dynamically Detuned IR-FEL Oscillator and Pulse Stacking at an External Cavity FEL, cavity, electron, simulation 1778
 
  • Y. Sumitomo, Y. Hayakawa, T. Sakai
    LEBRA, Funabashi, Japan
  • R. Hajima
    QST, Tokai, Japan
 
  Funding: Q-LEAP program supported by Ministry of Education, Culture, Sports, Science and Technology, Japan
At the LEBRA facility of Nihon U., we have an IR-FEL oscillator to generate radiations in the range of wavelengths 1-6 um for various experiments. A research program has been established to explore the application of the IR-FEL to generate attosecond UV and X-ray pulses through the high harmonic generation (HHG) in noble gases, where the IR-FEL pulses must have a high-peak power and a short-pulse duration. The property of generated FEL pulse is affected by the cavity length detuning of FEL oscillator as well as the small signal gain and the cavity loss. The operation at a small- or zero-detuning length is necessary to generate a FEL pulse shorter than the bunch length, although it requires a long macro-pulse to reach the saturation. For the short FEL pulse generation within a limited macro-pulse length at the LEBRA LINAC, we apply a dynamical modulation to the electron bunch repetition, that is equivalent to a dynamical detuning of the FEL cavity length. We illustrate the potential performance of the IR-FEL with the dynamical detuning by time-dependent 3D FEL simulations. We also evaluate the enhancement of the FEL pulses by an external cavity stacking for the sake of the HHG application.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB041  
About • paper received ※ 29 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB045 Stimulated Excitation by Seeding With Cherenkov Radiation in an Optical Cavity cavity, electron, GUI, ion-source 1785
 
  • S.M. Jiang, Z.G. He, Q.K. Jia, W.W. Li, L. Wang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  • D. He
    Anhui Electrical Engineering Professional Technique College, Hefei, People’s Republic of China
 
  Funding: Work supported by National Foundation of Natural Sciences of China (11775216, 11705198, 11675178), and Fundamental Research Funds for the Central Universities (WK2310000061).
By seeding with narrow-band Cherenkov radiation from a dielectric loaded waveguide(DLW), stimulated excitation in an optical cavity is presented. The evolution and energy loss of the field oscillating in optical cavity is analysed by the theoretical and numerical calculation. The results show that the high order TM modes of the Cherenkov radiation can be better preserved after a large number of roundtrips in the optical cavity and this scheme offers a potential method of realizing high power Terahertz radiation source in a compact facility.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB045  
About • paper received ※ 30 April 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB046 Second Order Intensity Correlation and Statistical Properties of a Soft X-Ray Free Electron Laser laser, FEL, electron, simulation 1788
 
  • C.L. Li, J.H. Chen, Z.C. Chen, X.T. Wang, H.L. Wu
    SINAP, Shanghai, People’s Republic of China
  • B. Liu, T. Liu
    SARI-CAS, Pudong, Shanghai, People’s Republic of China
 
  High degree of transverse field coherence is one of the unique properties of an FEL compared with a 3rd gen-eration storage ring light source. As a result, the FEL advances the development of innovative research and technology that was not previously feasible. A truly coherent source should be coherent in all orders de-scribed from the intensity correlation functions. In this paper, second order intensity correlation of FEL radia-tion is investigated based on the Hanbury Brown-Twiss intensity correlation method. The statistical properties of radiation produced from SASE was also investigated and compared with the statistical proper-ties of a phase-locked laser. The results show that the statistical properties of a SASE mode behave as a cha-otic source, which is significantly different from the properties of a phase-locked laser beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB046  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB050 The Optical Resonator of CTFEL for Range of 1 to 2 THz FEL, GUI, electron, coupling 1795
 
  • X.J. Shu, Y.H. Dou
    Institute of Applied Physics and Computational Mathematics, People’s Republic of China
 
  A high power THz free electron laser (FEL) facility is under construction at China Academy of Engineering Physics (CTFEL). The radiation frequency of the FEL facility will be tuned in range of 1~3 THz and the average output power is about 10 W. The system mainly consists of a GaAs photoemission DC gun, superconductor accelerator, hybrid wiggler, optical cavity. The first lasing is obtained on Aug. 29, 2017, and CTFEL is operated in range of 2-4THz, but cannot lasing at the frequency below 1.8 THz. The optical resonator of CTFEL must be optimized to ensure lasing in range of 1 to 2 THz.. The lasing strongly depends on the performance of the optical resonator including output efficiency, gain and round-trip loss. The optical resonator consists of metal-coated reflect mirror, the centre-hole output mirror, waveguide. The influence of waveguide on the quality of optical cavity is evaluated by the 3D OSIFEL code. The waveguide size and output hole radius is optimized to different frequencies between 1 THz to 2 THz.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB050  
About • paper received ※ 13 May 2019       paper accepted ※ 24 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB052 The Mini-Period Permanent Magnet Staggered Undulator for Compact X-Ray Free Electron Laser undulator, FEL, electron, permanent-magnet 1797
 
  • L.G. Yan, D.R. Deng, J. Wang
    CAEP/IAE, Mianyang, Sichuan, People’s Republic of China
 
  Funding: Work supported by National Natural Science Foundation of China under grant of 11505174, 11505173 and 11605190.
Miniaturization of X-ray free electron laser requires reduction of undulator period length. In this proceeding, a mini-period permanent magnet staggered undulator was proposed, which is free of superconducting solenoid and thus has advantages of easy-manufacture and low-cost. After optimization, it can generate periodic field of peak field 0.71 T with period length 10 mm and pole gap 2 mm, which has been verified on a prototype. Combined with X-band linac, the length of 1 nm XFEL facility using the permanent magnet staggered undulator can be confined within 44 m.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB052  
About • paper received ※ 30 April 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB057 THz-Pump and UV-Probe Scheme Based on Storage Ring laser, electron, bunching, storage-ring 1811
 
  • H.R. Zhang, Z.G. He, S.M. Jiang, W.X. Wang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  We propose a THz-pump and UV-probe scheme based on storage ring for ultra-fast dynamics experiment. In which, two sequential laser pulses, one of which has a periodic intensity envelope, simultaneously interact with different parts of the long electron beam in a modulator; after a chicane, the part that interacts with the periodic pulse will bunch at THz domain and radiate through a bend magnet, another based on high-harmonic generation will bunch at UV domain and radiate at a radiator. The electron beam can be utilized circularly in the storage ring, which will increase its average power. The feasibility of this THz-pump and UV-probe scheme is verified in both theory and simulation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB057  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB061 Seeded Free-Electron Lasers Driven by a Transverse Tilted Electron Bunch laser, FEL, electron, undulator 1817
 
  • Z. Zhao, Q.K. Jia, H.T. Li
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  Funding: Work supported by the China Postdoctoral Science Foundation (No. 2018M642542) and the Fundamental Research Funds for the Central Universities (WK2310000081).
A transverse tilt of the electron bunch is normally unwanted in free-electron laser (FEL) since only a portion of the bunch can contribute to the FEL radiation. However, the recent researches demonstrate that the tilted bunch can be used to generate FEL with some special features. In this work we investigate the generation of a large tilt of the bunch by using a corrugated structure and a dogleg separately. Based on the tilted bunch, the creation of ultra-short pulse and multi-color pulses are demonstrated in high-gain harmonic generation (HGHG) FEL.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB061  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB062 Coherence Time Characterization for Self-Amplified Spontaneous Emission Free-Electron Lasers electron, FEL, laser, free-electron-laser 1820
 
  • G. Zhou, Y. Jiao, J.Q. Wang
    IHEP, Beijing, People’s Republic of China
  • T.O. Raubenheimer, J. Wu
    SLAC, Menlo Park, California, USA
  • C.-Y. Tsai
    HUST, Wuhan, People’s Republic of China
  • C. Yang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  One of the key challenges in scientific researches based on free-electron lasers (FELs) is the characterization of the coherence time of the ultra-fast hard x-ray pulse, which fundamentally influences the interaction process between x-ray and materials. Conventional optical methods, based on autocorrelation, is very difficult to realize due to the lack of mirrors. Here, we experimentally demonstrate a conceptually new coherence time characterization method and a coherence time of 174.7 attoseonds has been measured for the 6.92 keV FEL pulses at Linac Coherent Light Source. In our experiment, a phase shifter is adopted to control the cross-correlation between x-ray and microbunched electrons. This approach provides critical temporal coherence diagnostics for x-ray FELs, and is decoupled from machine parameters, applicable for any photon energy, radiation brightness, repetition rate and FEL pulse duration, etc.
The work was supported by the US Department of Energy (DOE) under contract DE-AC02-76SF00515 and the US DOE Office of Science Early Career Research Program grant FWP-2013-SLAC-100164.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB062  
About • paper received ※ 01 May 2019       paper accepted ※ 28 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB071 Considerations on Implementing EEHG with a Strong Linear Chirp electron, bunching, FEL, linac 1830
 
  • M.A. Pop, S. Werin
    MAX IV Laboratory, Lund University, Lund, Sweden
 
  As the ECHO enabled harmonic generation (EEHG) scheme draws such intense focus from the FEL community, we conduct simulations to evaluate the challenges of implementing said scheme in different FEL layouts. Nonlinear processes such as this require extensive simulations to harmonize all system specific properties like seed lasers and electron beam properties. Along with optimizing the original EEHG scheme* one can consider, for example, altering the seed laser pulse to optimize the bunching for a machine specific chirp. We study the EEHG as a possible seeding method aimed at increasing coherence of the photon beam for the prospective SXL FEL beamline at MAXIV. The particular chirp of the electron beam through the MAXIV LINAC generates some specific requirements in implementing EEHG but may also offer an opportunity for exotic operation modes of this FEL.
* Xiang D. and Stupakov G. Echo-enabled harmonic generation free electron laser 10.1103/PhysRevSTAB.12.030702
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB071  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB076 Free Electron Laser Driven by a High-Energy High-Current Energy-Recovery Linac FEL, electron, linac, undulator 1844
 
  • F. Zimmermann
    CERN, Geneva, Switzerland
  • H. Aksakal
    KMSIU, Onikisubat / Kahramanmaras, Turkey
  • A.A. Aksoy
    Ankara University, Accelerator Technologies Institute, Golbasi, Turkey
  • Z. Nergiz
    Nigde University, Nigde University Science & Art Faculty, Nigde, Turkey
 
  Funding: This work was supported by the European Commission under the HORIZON 2020 project ARIES, grant agreement no. 730871.
The proposed electron-hadron collider LHeC, based on an energy recovery linac, employs an electron beam of 20 mA current at an energy of tens of GeV. This electron beam could also be used to drive a free electron laser (FEL) operating at sub-Angstrom wavelengths. Here we demonstrate that such FEL would have the potential to provide orders of magnitude higher peak power, peak brilliance and average brilliance, than any other FEL, either existing or proposed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB076  
About • paper received ※ 10 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB089 Undulator Radiation Generated by a Single Electron electron, undulator, photon, experiment 1867
 
  • A. Halavanau, Z. Huang, C. Pellegrini, T.O. Raubenheimer
    SLAC, Menlo Park, California, USA
  • I. Lobach
    University of Chicago, Chicago, Illinois, USA
  • S. Nagaitsev
    Fermilab, Batavia, Illinois, USA
  • D. Seipt
    HZDR, Dresden, Germany
 
  Funding: This work was supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515.
The facilities providing single electron beams are currently being commissioned at Fermilab and will be at SLAC. Recently, Fermilab’s IOTA ring routinely demonstrated circulation of a single electron at 100 MeV beam energy. Alternatively, SLAC is working on constructing LCLS-II an X-ray FEL driven by a 4 GeV SRF linac. A parasitic beamline, S30XL, is planned that will extract 4 GeV dark current from between the primary LCLS-II electron bunches. The dark current will be delivered to End Station A and can work independently of LCLS-II experiments. The dark current will be bunched at a frequency of 46 MHz while extracted current varied from single electrons to 10’s of nA. In the present paper, we estimate the feasibility of propagating single electron beams through a conventional undulator, placed in the IOTA and S30XL beamlines. We explore the possible observable effects and experimental parameters range. In addition, we focus on potential applications of such beams in systems for high fidelity quantum measurements.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB089  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB090 Preliminary Considerations of Atomic Inner-Shell X-Ray Laser for Self-Seeding at LCLS-II FEL, photon, simulation, experiment 1871
 
  • A. Halavanau, C. Pellegrini, J. Wu
    SLAC, Menlo Park, California, USA
  • A.I. Benediktovitch
    EuXFEL, Hamburg, Germany
  • N. Rohringer
    Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
 
  Funding: This work was supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515.
The atomic inner-shell X-ray lasing, induced by the irradiation of focused XFEL SASE pulses, was demonstrated in gases, liquid jets and solids. In this proceeding, we discuss the possible use of this concept in self-seeding scheme at LCLS-II. We provide a preliminary study of different lasing media and corresponding SASE XFEL parameters. For the case of noble gas inner-shell X-ray laser, we study the requirements for gas pressure and XFEL pulse focusing. Finally, we discuss possible designs of this system and its advantages in LCLS-II operations.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB090  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB091 Study of XFEL Third Harmonic Radiation at LCLS undulator, FEL, experiment, bunching 1875
 
  • C. Emma, M.W. Guetg, A. Halavanau, A.A. Lutman, G. Marcus, T.J. Maxwell, C. Pellegrini
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515.
In this paper, we focus on characterization of the nonlinear third harmonic radiation properties at Linac Coherent Light Source (LCLS). In addition, we experimentally perform third harmonic self-seeding, using diamond crystal attenuator in the hard X-ray self-seeding chicane. We discuss warm beam effects in such scheme, justifying recently proposed two bunch configuration for harmonic lasing.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB091  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB092 Cherenkov Radiation in Periodic Wire Medium Formed by Transversely Modulated Electron Beams electron, laser, cathode, experiment 1878
 
  • A. Halavanau
    SLAC, Menlo Park, California, USA
  • A.I. Benediktovitch
    EuXFEL, Hamburg, Germany
  • E.A. Gurnevich
    Belarussian State University, Scientific Research Institute of Nuclear Problems, Minsk, Belarus
 
  Funding: Work was supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515.
We investigate the properties of Cherenkov, quasi-Cherenkov (parametric) and diffraction radiation generated in the periodic conducting wire medium by transversely modulated electron beams. Such beams were recently obtained at Argonne Wakefield Accelerator (AWA) facility using microlens array (MLA) laser shaping technique. We consider in details the case of one dimensional periodic tungsten wire structure and transverse electron beamlets separation of mm scale. We look at possible enhancements of the radiation field due to transverse periodicity of the electron beam.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB092  
About • paper received ※ 14 May 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPTS032 Radiation Design of New 30 kW Beam Dump of J-PARC Main Ring neutron, vacuum, proton, site 2005
 
  • M.J. Shirakata, H. Kuboki, J. Takano
    KEK, Ibaraki, Japan
 
  The J-PARC Main Ring (MR) has a beam dump for the beam study and beam abort. Its present capacity is 7.5 kW in one hour average which is limited by radiation condition for the environments. The number of protons in one MR cycle is 2.6·10+14 in recent days, which corresponds to the beam power of 500 kW. As the top energy of J-PARC MR is 30 GeV, the number of available beam shots is restricted to less than twenty in one hour with such an intense beam. It imposes a big limitation on high power beam tuning and study. The number of protons is expected to become 3.3·10+14 for MW operation. Hence, an upgrade of the beam dump from 7.5 kW to 30 kW is planned. The radiation dose rate should be less than 0.25μSv/h on the ground. The backscattered neutron flux should be examined in the accelerator tunnel. The new dump design on radiation matters is described in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS032  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPTS046 Commissioning of a Compact THz Source Based on FEL linac, FEL, undulator, cavity 2030
 
  • Y.J. Pei, G. Feng, X.Y. He, Y. Hong, D. Jia, P. Lu, S. Lu, L. Shang, B.G. Sun, Zh. X. Tang, W. Wang, X.Q. Wang, W. Wei
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  • L. Cao, Q.S. Chen, Q. Fu, T. Hu, P. Tan, Y.Q. Xiong
    HUST, Wuhan, People’s Republic of China
  • G. Huang
    IMP/CAS, Lanzhou, People’s Republic of China
  • L.G. Shen, F. Zhang
    USTC/PMPI, Hefei, Anhui, People’s Republic of China
 
  The layout of the THz source based on FEL was de-scribed in this paper. The THz source was based on a FEL which was composed of a compact 8-14MeV LINAC, undulator, optical resonance, THz wave measurement system and so on. The facility was designed in 2013 and the typical running parameter got in 2017 were as the following: energy is of 12.7MeV, energy spread is of 0.3%, macro-pulse is of 4 μs, pulse length of micro-pulse is of 6ps, emittance is of 24 mm.mrad. After that the ma-chine was commissioning for production THz radiation. In November 2018, the THz wave was test and got THz wave signal, the spectrum was also got. This year, we plan to measure the output power of the THz source.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS046  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEXXPLS2 Accelerator Vacuum Windows: A Review of Past Research and a Strategy for the Development of a New Design for Improved Safety and Longevity for Particle Accelerators vacuum, Windows, experiment, scattering 2237
 
  • C.R. Ader, M.L. Alvarez, J.S. Batko, R. Campos, M.W. McGee, A.C. Watts
    Fermilab, Batavia, Illinois, USA
 
  Funding: Fermi National Accelerator Laboratory
Vacuum window research continues at Fermilab and this paper will examine cost effective, consistent designs which can have a significant impact on accelerator laboratories in terms of safety and cost. Issues such as the design, materials, analysis, testing and fabrication are addressed, including beam scattering and materials cost-benefit analysis and examining potential material substitutes for beryllium. A previous research paper has examined current fabrication and design techniques and also failure modes at Fermi, and this paper focuses on emerging and novel technologies for vacuum window fabrication. Many different paths have been taken by High Energy Physics (HEP) Laboratories throughout the world with varying success. The history of vacuum window development is extensive and not well defined, and a matrix of the research already completed on materials and joint design for vacuum windows will be shown. This report finally includes a treatise for vacuum window technology and a view towards emerging designs and materials and discusses future advances of research such as fabrication techniques including additive manufacturing and ultrasonic welding. Further exploration into these would prove beneficial to developing vacuum windows that are safer and stronger while being more transparent to the beam.
 
slides icon Slides WEXXPLS2 [3.139 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEXXPLS2  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEYYPLS3 Development of Methods for Calculation of Bunch Radiation in Presence of Dielectric Objects target, simulation, vacuum, focusing 2274
 
  • A.V. Tyukhtin, E.S. Belonogaya, S.N. Galyamin, V.V. Vorobev
    Saint Petersburg State University, Saint Petersburg, Russia
 
  Funding: This work was supported by the Russian Science Foundation (Grant # 18-72-10137).
Radiation of charged particles moving in presence of dielectric targets is of interests for various applications in accelerator and beam physics*. Typically, the size of the target is much larger than the wavelengths under consideration. This fact gives us an obvious small parameter of the problem and allows developing approximate methods of analysis. We develop two methods: "ray-optical method" and "aperture method"**. These methods can be very effective for all situations where we can find the tangential field components on the "aperture" which is an object boundary illuminated by Cherenkov radiation. We apply the aperture method to different dielectric objects including a prism, a cone, and a ball. Electromagnetic field is analyzed on different distances from the objects. The special attention is given to investigation of the field in the far-field (Fraunhofer) area having large importance for various applications. We obtain analytical results for different objects, demonstrate typical radiation patterns and discuss new physical effects, in particular, the phenomenon of concentration of radiation and effect of "Cherenkov spotlight". Prospects of use of aperture method and ray-optical one for other objects are discussed as well.
* R.Kieffer et al, PRL, 121, 054802 (2018).
** E.S.Belonogaya et al, JOSA B, 32, 649 (2015); S.N.Galyamin, A.V.Tyukhtin, PRL, 113, 064802 (2014); A.V.Tyukhtin et al, J. Instrum., 13, C02033 (2018).
 
slides icon Slides WEYYPLS3 [4.063 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEYYPLS3  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEZPLS1 Control of Laser Plasma Accelerated Electrons: A Route for Compact Free Electron Lasers electron, laser, undulator, FEL 2280
 
  • M.-E. Couprie, T. André, F. Blache, F. Bouvet, F. Briquez, Y. Dietrich, J.P. Duval, M. El Ajjouri, A. Ghaith, C. Herbeaux, N. Hubert, C.A. Kitegi, M. Labat, N. Leclercq, A. Lestrade, A. Loulergue, O. Marcouillé, F. Marteau, D. Oumbarek Espinos, P. Rommeluère, M. Sebdaoui, K.T. Tavakoli, M. Valléau
    SOLEIL, Gif-sur-Yvette, France
  • I.A. Andriyash, S. Corde, J. Gautier, J.-P. Goddet, O. S. Kononenko, G. Lambert, K. Ta Phuoc, A. Tafzi, C. Thaury
    LOA, Palaiseau, France
  • S. Bielawski, C. Evain, E. Roussel, C. Szwaj
    PhLAM/CERLA, Villeneuve d’Ascq, France
  • V. Malka
    Weizmann Institute of Science, Physics, Rehovot, Israel
 
  The recent spectacular development of laser plasma ac- celerators that now can deliver GeV electron beams in an extremelyshortdistancemakesthemverypromising. Ap- plications for light sources based on undulator radiation and free electron laser appear as an intermediate step to move from an acceleration concept to an accelerator qual- ification. However, the presently achieved divergence and energy spread require some electron beam manipulations. The COXINEL test line was designed for enabling Free Elec- tron Laser operation with baseline reference parameters. It comprises variable permanent magnet quadrupoles for di- vergence handling, a magnetic chicane for electron energy sorting, a second set of quadrupole for chromatic focusing and an undulator for synchrotron radiation emission and/or free electron laser gain medium. The transport along the line is controlled [1]. The synchrotron radiation emitted by the undulator radiation is studied under different conditions of detection (CCD camera, spectrometer), electron beam manipulation and undulator parameters. These observations pave the way towards Laser Plasma Acceleration based Free Electron Laser.

[1] T. André et al., Control of laser plasma accelerated electrons for light sources, accepted in Nature Comm.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEZPLS1  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPMP007 Current Status of Slow Extraction from J-PARC Main Ring extraction, operation, proton, experiment 2311
 
  • R. Muto, Y. Arakaki, T. Kimura, S. Murasugi, M. Okada, K. Okamura, T. Shimogawa, Y. Shirakabe, M. Tomizawa, T. Toyama, E. Yanaoka
    KEK, Ibaraki, Japan
  • A. Matsumura
    Nihon Advanced Technology Co., Ltd, Ibaraki, Nakagun, Tokaimura, Japan
 
  A 30 GeV proton beam accelerated in the J-PARC Main Ring (MR) is slowly extracted by the third integer resonant extraction and delivered to the hadron experimental hall. The slow extraction (SX) from the MR has unique characteristics that can be used to obtain a low beam loss rate. A dynamic bump scheme under achromatic condition drastically reduces beam hit rate on the septa devices. We have attained 50 kW SX operation at 5.2s cycle in current physics run. Slow extraction efficiency has been achieved to be very high, 99.5%. A beam instability during debunching with beam loss can be suppressed by a unique RF phase offset technique at MR injection. A spill duty factor indicating a uniformity for time structure of the extracted beam is typically 50%, which can be obtained by a feedback system using fast response quadrupoles, applying transverse RF field and so on. Future plans to improve present SX performances will be introduced.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP007  
About • paper received ※ 01 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPMP024 Alternative Material Choices to Reduce Activation of Extraction Equipment extraction, shielding, vacuum, proton 2363
 
  • D. Björkman, B. Balhan, J.C.C.M. Borburgh, L.S. Esposito, M.A. Fraser, B. Goddard, L.S. Stoel, H. Vincke
    CERN, Geneva, Switzerland
 
  At CERN, the Super Proton Synchrotron (SPS) is equipped with a resonant slow extraction system in Long Straight Section 2 (LSS2) towards the fixed target (FT) beam lines in the North Area. The extraction region provides the physics experiments with a quasi-DC flux of high-energy protons over a few seconds, which corresponds to tens of thousands of turns. The resonant slow extraction process provokes beam losses and is therefore the origin of radiation damage and the production of induced radioactivity in this region of the machine. This induced radioactivity imposed high constraints on the equipment design to be reliable to minimise the radiation exposure to personnel during machine maintenance. A detailed FLUKA model was developed in order to better understand the beam loss patterns, activation of the machine and to identify equipment components that could be optimised to reduce the residual dose related hazards. Simulations identified multiple alternative materials for extraction equipment components as well as shielding locations, which implementation could reduce residual activation hazards.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP024  
About • paper received ※ 26 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPMP041 Damping Bunch Oscillations Due to Off-Axis Injection optics, injection, wiggler, damping 2422
 
  • F. Zimmermann, O. Etisken, N. Mounet, A. Oeftiger, S. Ogur, Y. Papaphilippou, B. Salvant
    CERN, Geneva, Switzerland
  • K. Oide
    KEK, Ibaraki, Japan
 
  Funding: This work was supported by the European Commission under the HORIZON 2020 project ARIES, grant agreement no. 730871.
In the FCC-ee pre-injector complex, a slightly modified SPS can serve as pre-booster. The baseline design foresees injecting the low-emittance electron and positron bunches off-axis into the SPS, and deploying strong wigglers to greatly enhance the radiation damping at the injection energy. We here compare the damping of large injection oscillations by means of radiation damping with the effect of other possible damping mechanisms such as a fast bunch-by-bunch feedback system and/or head-tail damping via nonzero chromaticity. As a by-product, we investigate the transverse beam stability.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP041  
About • paper received ※ 10 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPMP044 Mu2e Electrostatic Septa Volumetric Exchange of Fc-40 Dielectric in High Radiation Environments GUI, septum, cathode, extraction 2434
 
  • M.L. Alvarez, A. Deshpande, K.R. Hunden, V.P. Nagaslaev, E. Pirtle
    Fermilab, Batavia, Illinois, USA
 
  Funding: * Operated by FRA, LLC under Contract No. DEAC02-07CH11359 and Grant Award No. LAB 18-1802 with the United States Department of Energy.
Two electrostatic septa (ESS) are being designed for the slow extraction of 8 GeV proton beam for the Mu2e experiment at Fermilab. Special attention is given to the high voltage feedthrough (HVF), which energizes the cathode creating the bending field. The FC-40 dielectric fluid, surrounding the HV cable breaks down from radiation exposure, which reduces its insulating capabilities. The new HVF design focuses on effective replacement of the exposed fluid and eliminating the stagnant areas of low exchange rate. A preliminary test using a fully transparent prototype HVF and water was conducted to understand the volumetric exchange rate of the high radiation region. Here we discuss the results of these tests and further studies using the FC-40.
** malvare4@fnal.gov
*** vnagasl@fnal.gov
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP044  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW006 Development of a Beam Loss Monitor and Transverse Beam Dynamics Studies at ARRONAX C70XP Cyclotron cyclotron, experiment, operation, quadrupole 2470
 
  • A. Sengar, X. Goiziou, F. Gomez Serito, C. Koumeir, F. Poirier
    Cyclotron ARRONAX, Saint-Herblain, France
  • F. Haddad
    SUBATECH, Nantes, France
 
  Funding: "Investissements d’Avenir", Equipex Arronax-Plus, Institute of Nuclear and Particle Physics from the National Scientific Research center (CNRS) and the Regional Council of Pays de la Loire, France.
The ARRONAX Interest Public Group uses a multi-particle, high energy and high intensity industrial accelerator which has several beamlines used for various purposes. For improvement of operations, ARRONAX has foster and installed robust air-based Beam Loss Monitors (BLMs) outside the beam pipes. BLMs consist of four active detecting plates and are integrated within the experimental physics and industrial control system (EPICS) monitoring and data acquisition system. Each BLM has been tested for the pre-commissioning phase with beams at low intensity (600pA to 6nA on target). Comparative studies and selection of the BLMs has led to their installation at high intensity beam lines. BLMs are now used in beam dynamics studies to investigate transverse characteristics while in regular operation. They support present and future operations extension foreseen at ARRONAX. The results from experimental studies on BLMs at low beam intensity and status of beam dynamics studies at high intensity (A) are presented here. Keywords: BLM, beam dynamics, EPICS, Gas ionization detector, cyclotron, proton.
*F. Poirier, S. Girault, STUDIES AND UPGRADES ON THE C70 CYCLOTRON ARRONAX, Proceedings of Cyclotrons 2016, Zurich, Switzerland
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW006  
About • paper received ※ 30 April 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW014 A Non-Invasive THz Spectrometer for Bunch Length Characterization at European XFEL electron, FEL, diagnostics, factory 2495
 
  • N.M. Lockmann, C. Gerth, P. Peier, B. Schmidt, S. Wesch
    DESY, Hamburg, Germany
 
  The European X-ray Free-Electron Laser provides one of the most powerful X-ray laser pulses to a wide range of experiments. These experiments strongly benefit from the exact knowledge of the electron bunch current profile and demand for stable and shortest-possible pulse lengths. During the 2018 summer shutdown, the 4-staged grating spectrometer CRISP* has been installed at a diffraction radiation (DR) beamline just upstream of the undulator beamline switchyard. The DR at final electron beam energies of up to 17.5 GeV enables non-invasive bunch length characterization based on form factor measurements down to a few micrometers. Fast detectors and electronics allow for the characterization of the whole bunch train with repetition rates above 1 MHz. This contribution will present commissioning results of the THz beamline as well as first measured form factors and reconstructed electron current profiles.
* S. Wesch et al., Nuclear Instruments and Methods in Physics Research Section A 665 (2011) pp. 40-47
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW014  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW016 Turn-by-Turn Horizontal Bunch Size and Energy Spread Studies at KARA synchrotron, detector, synchrotron-radiation, storage-ring 2498
 
  • B. Kehrer, M. Brosi, E. Bründermann, S. Funkner, A.-S. Müller, G. Niehues, M.M. Patil, M. Schuh, J.L. Steinmann
    KIT, Karlsruhe, Germany
  • L. Rota
    SLAC, Menlo Park, California, USA
 
  Funding: This work is funded by the BMBF under contract number: 05K16VKA
The energy spread is an important beam dynamics parameter. It can be derived from measurements of the horizontal bunch size. At the KIT storage ring KARA a fast-gated camera is routinely used for horizontal bunch size measurements with a single-turn resolution for a limited time span. To overcome the limits of the current camera setup in respect to resolution and time span, a high-speed line array with up to 10 Mfps, the KALYPSO system, is foreseen as a successor. The KALYPSO versions range from 256-pixel to 1024-pixel and allow unlimited turn-by-turn imaging of a single bunch at KARA. We successfully tested such a system at our visible light diagnostics port and present first results in this contribution.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW016  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW018 An Ultra-Fast and Wide-Spectrum Linear Array Detector for High Repetition Rate and Pulsed Experiments detector, experiment, electron, synchrotron 2504
 
  • M.M. Patil, E. Bründermann, M. Caselle, S. Funkner, B. Kehrer, A.-S. Müller, G. Niehues, W. Wang, M. Weber
    KIT, Karlsruhe, Germany
  • C. Gerth
    DESY, Hamburg, Germany
  • D.R. Makowski, A. Mielczarek
    TUL-DMCS, Łódź, Poland
 
  Funding: "BMBF: is funded by the BMBF contract number: 05K16VKA" (2016-2018) ("NeoDyn")
Photon science research at accelerators is influenced radically by the developments of sensor and readout technologies for imaging. These technologies enable a wide range of applications in beam diagnostics, tomography and spectroscopy. The repetition rate of commercially available linear array detectors is a limiting factor for the emerging synchrotron applications. To overcome these limitations, KALYPSO(Karlsruhe Linear arraY detector for MHz rePetition rateSpectrOscopy), an ultra-fast and wide-field of view linear array detector operating at several mega-frames per second(Mfps), has been developed. A silicon micro-strip sensor is connected to custom cutting-edge front end ASICs to achieve unprecedented frame rate in continuous readout mode. In this contribution, the third generation of KALYPSO will be presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW018  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW022 A Numerical Analysis to Choose the Most Performing Optical Transition Radiation Screen target, electron, brightness, site 2518
 
  • F. Cioeta, D. Alesini, A. Variola
    INFN/LNF, Frascati (Roma), Italy
  • M. Ciambrella, A. Mostacci
    Sapienza University of Rome, Rome, Italy
  • D. Cortis, M. Marongiu, V. Pettinacci
    INFN-Roma, Roma, Italy
 
  Optical Transition Radiation (OTR) screen represents the most appropriate instrument to measure and verify the characteristics of a beam spot size produced by a particle accelerator. In order to measure such beam properties, OTR screens have to sustain thermal and mechanical stresses due to the energy that several bunches deposit. Owing to these requirements, it is essential to identify the more suitable material to optimize the OTR dimensions and to get reliable measures from the diagnostic system. In this paper, we describe a numerical procedure to choose the most performing material taking into account the physical requirements of a multi-bunch high brightness. The procedure is based on a dedicated ANSYS script able to evaluate the fatigue life time of the material considering a high number of thermal cycles generated by several bunches. The main characteristic of this script is the capability to simulate the real thermal and mechanical effect on the target that the hitting particle beam produces. The numerical procedure has been applied to compare the performance of three relevant materials-Aluminium, Silicon and Graphite simulating a beam hitting with well-known parameters.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW022  
About • paper received ※ 13 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW031 Measurement of Cherenkov Diffraction Radiation from a Short Electron Bunches at t-ACTS electron, experiment, photon, detector 2536
 
  • S. Ninomiya, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, N. M. Morita, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, K. Takahashi, H. Yamada
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
 
  Cherenkov Diffraction Radiation (ChDR) can be considered as a tool of non-destructive beam diagnostics. It also has the feature that the photon flux of ChDR is proportional to the thickness of the dielectric used as the radiator and can be much larger than ordinary diffraction radiation. An experimental set-up for the measurement of coherent ChDR from short electron bunches of about 100 fs is being prepared at t-ACTS, Tohoku University. Results of a basic experimental study about coherent ChDR will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW031  
About • paper received ※ 16 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW046 Key Technologies for Remote Detection of CSNS Radiation Environment vacuum, controls, operation, target 2584
 
  • L. Kang, R.H. Liu, X.J. Nie, A.X. Wang, G.Y. Wang, D.H. Zhu
    IHEP, Beijing, People’s Republic of China
  • J.X. Chen, H.Y. He, L. Liu, C.J. Ning, J.B. Yu, Y.J. Yu, J.S. Zhang
    IHEP CSNS, Guangdong Province, People’s Republic of China
 
  Funding: Work supported by National Nature Science Foundation of China (11375217)
China Spallation Neutron Source (CSNS) has been continuously operating in September 2018. As the operating time increases the radiation dose will also increase, some equipment maintenance and testing must take special tools and equipment. This article mainly introduced the studies on radiation environment of several detection technologies, such as: remote vacuum leak detection methods and equipment, strong magnetic field environment vibration measuring technology, using Qr code tracing machine walking vehicle inspection system and remote image vision measurement technology, etc., these advanced technology also has a guiding significance to other related fields.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW046  
About • paper received ※ 23 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW052 A Rotation Method to Calibrate BPM Electric Offsets laser, site, instrumentation, proton 2595
 
  • M.W. Wang, X. Guan, P.F. Ma, X.W. Wang, S.X. Zheng
    TUB, Beijing, People’s Republic of China
  • M.T. Qiu, D. Wang, Z.M. Wang
    NINT, Shannxi, People’s Republic of China
 
  Beam position monitor is a key instrument for machine commissioning. To measure beam position accurately, offline calibrations to acquire the sensitivity and offsets of the BPM are essential prerequisites. A new method to calibrate the BPM electric offset is proposed in this paper. By measuring the location variation of the BPM electric center after rotatingtheBPM180degrees, theBPMoffsetcanbederived. The method is more convenient, universal and accurate than the traditional methods. The method is successfully applied to calibrate the button BPM of Xi’an Proton Application Facility. The repetitive measurement error is 20.8 um.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW052  
About • paper received ※ 16 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW055 Beam Longitudinal Distribution Reconstructed by GESPAR Method at CAEP THz FEL electron, FEL, laser, experiment 2602
 
  • D. Wu, T.H. He, P. Li, J. Liu, X. Luo, Q. Pan, L.J. Shan, X. Shen, J. Wang, D.X. Xiao, L.G. Yan, P. Zhang, K. Zhou
    CAEP/IAE, Mianyang, Sichuan, People’s Republic of China
 
  Funding: Work supported by National Natural Science Foundation of China with grant (11505173, 11505174, 11575264, and 11605190)
Coherent radiation can be used to measure the longitudinal distribution of the electron beam bunch of any length, as long as the coherent radiation spectrum can be measured. In many cases, the Kramers-Krönig relationship is used to reconstruct the temporal distribution of the beam from the coherent radiation spectrum. However, the extrapolation of the low frequency will introduce the uncertainty of the reconstruction. In this paper, GrEedy Sparse PhAse Retrieval (GESPAR) method was used to reconstruct the beam longitudinal distribution measured by coherent transition radiation on the THz FEL facility of China Academy of Engineering Physics. The results indicate that the GESPAR method works well for the complex and ultrashort distribution. It will be an effective tool to accurately measure the femtosecond bunch temporal structure.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW055  
About • paper received ※ 14 May 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW068 Measurements of Beam Parameters at the Last Track of the ERL-Based Novosibirsk Free Electron Laser FEL, electron, diagnostics, undulator 2632
 
  • V.M. Borin, Ya.V. Getmanov, A.S. Matveev, O.I. Meshkov, O.A. Shevchenko, N.A. Vinokurov
    BINP SB RAS, Novosibirsk, Russia
  • V.L. Dorokhov
    BINP, Novosibirsk, Russia
  • Ya.V. Getmanov
    NSU, Novosibirsk, Russia
  • A.I. Mickailov
    Budker INP & NSU, Novosibirsk, Russia
 
  Parameters and dynamics of the electron beam of the Novosibirsk infrared Free Electron Laser are studied. The Novosibirsk FEL is based on the multi-turn energy recovery linac (ERL). The ERL operate in CW mode with an average beam current about 5 mA. Therefore non-destructive beam diagnostic methods are preferable. The beam energy at the last track of the ERL is 42 MeV. As a result, significant part of synchrotron radiation from bending magnets is in the visible range and can be used for diagnostic purposes. The transverse beam dimensions were measured with the optical diagnostics before (transition radiation) and after (synchrotron radiation from a bending magnet) the undulator applied for generation of middle-infrared coherent radiation. The obtained data are used to calculate the beam energy distribution and emittance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW068  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW077 Recent Results using Incoherent Cherenkov Diffraction Radiation for Non-Invasive Beam Diagnostics experiment, photon, diagnostics, beam-diagnostic 2654
 
  • M. Bergamaschi, R. Kieffer, T. Lefèvre, S. Mazzoni
    CERN, Geneva, Switzerland
  • A. Aryshev
    KEK, Ibaraki, Japan
  • P. Karataev
    Royal Holloway, University of London, Surrey, United Kingdom
  • P. Karataev, K. Lekomtsev
    JAI, Egham, Surrey, United Kingdom
  • A. Potylitsyn
    TPU, Tomsk, Russia
  • A. Schloegelhofer
    TU Vienna, Wien, Austria
 
  When a relativistic charged particle travels at a short distance from the surface of dielectric material Cherenkov Diffraction Radiation (ChDR) is produced inside the dielectric. Recent observation of incoherent ChDR in the visible spectrum has opened the possibility of using this radiation for non-invasive beam size and position measurements. An experimental test to study this technique for highly directional beam position measurement has been initiated on the CLEAR facility at CERN, whilst another experimental investigation is underway at the Accelerator Test Facility 2 (ATF2) at KEK, Japan, to measure the resolution limit of ChDR for beam imaging diagnostics. This contribution presents the latest experimental results from both of these test facilities.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW077  
About • paper received ※ 01 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW078 Development and Test of a Beam Imaging System Based on Radiation Tolerant Optical Fiber Bundles laser, experiment, target, site 2658
 
  • D. Celeste, E. Bravin, S. Burger, F. Roncarolo
    CERN, Geneva, Switzerland
 
  Many of the beam image systems at CERN are located in high radiation environments. In order to cope with this issue, VIDICON cameras are presently used but their production has been nowadays discontinued worldwide. The development of an alternative beam imaging system is described here, based on radiation tolerant optical fibre bundles. Such an optical line relays the image of a scintillating screen to a standard CMOS camera, located away from the high radiation zone. A prototype system based on a 10m long bundle with 104 fibres has been tested in the TT2 transfer line at CERN. The light transmission is rather low, but is compensated by the sensitivity of the CMOS camera. The system had a field of view of 60 mm and a spatial resolution of ~1 mm. The radiation hardness of such a fiber bundle was tested at the IRMA-CEA facility in Saclay, France. The bundle was irradiated at a rate of 3.6 kGy/h for 8 consecutive day. The total integrated dose achieved was ~700 kGy, which corresponds to about ten years of operation at the beam imaging station with the highest radiation dose at CERN. While the light transmission was reduced by 50%, this is still adequate to provide acceptable images.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW078  
About • paper received ※ 10 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW082 The Beam Gas Vertex Profile Monitoring Station for HL-LHC detector, target, real-time, dipole 2672
 
  • R. Kieffer, A. Alexopoulos, L. Fosse, M. Gonzalez Berges, H. Guerin, O.R. Jones, T. Marriott-Dodington, J.W. Storey, R. Veness, S. Vlachos, B. Würkner, C. Zamantzas
    CERN, Meyrin, Switzerland
  • S.M. Gibson
    Royal Holloway, University of London, Surrey, United Kingdom
 
  A new instrument is under development for the high luminosity upgrade of the Large Hadron Collider at CERN (HL-LHC) to provide non-invasive beam size measurements throughout the acceleration cycle. The Beam Gas Vertex (BGV) detector consists of a very low pressure gas target inside the beam pipe with a series of particle tracking stations located downstream. Inelastic collisions between the beam and the gas target produce secondary particles which are detected by the tracking stations. The beam size is measured from the spatial distribution of several thousand beam-gas interaction vertices, which are identified by means of the reconstructed tracks. A demonstrator device, operated over the past 3 years, has proven the feasibility of the BGV concept and has motivated development of a fully operational device for the HL-LHC. The status of current design studies for the future instrument will be presented, with particular emphasis on potential tracking detector technologies, readout schemes, and expected performance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW082  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW095 Coherent Transition Radiation Spatial Imaging as a Bunch Length Monitor electron, detector, simulation, focusing 2713
 
  • J. Wolfenden, R.B. Fiorito, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • M. Brandin, E. Mansten, S. Thorin
    MAX IV Laboratory, Lund University, Lund, Sweden
  • R.B. Fiorito, C.P. Welsch, J. Wolfenden
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • B.S. Kyle, T.H. Pacey, T.H. Pacey
    UMAN, Manchester, United Kingdom
  • B.S. Kyle
    University of Manchester, Manchester, United Kingdom
  • E. Mansten
    Lund University, Division of Atomic Physics, Lund, Sweden
  • T.H. Pacey
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • A.G. Shkvarunets
    UMD, College Park, Maryland, USA
 
  Funding: This work was supported by the EU under Grant Agreement No. 624890 and the STFC Cockcroft Institute core Grant No. ST/G008248/1.
High-resolution bunch length measurement is a key component in the optimisation of beam quality in FELs, storage rings, and plasma-based accelerators. Simulations have shown that the profile of a coherent transition radiation (CTR) image produced by a charged particle beam is sensitive to bunch length and can thus be used as a diagnostic. This contribution presents the development progress of a novel bunch length monitor based on imaging the spatial distribution of CTR. Due to the bunch lengths studied, 10fs-100fs FWHM, the radiation of interest was in the THz range. This led to the development of a THz imaging system, which can be applied to both high and low energy electron beams. The associated benefits of this imaging distribution methodology over the typical angular distribution measurement are discussed. Building upon preliminary multi-shot proof of concept results last year, a new series of experiments have been conducted in the short pulse facility (SPF) at MAX IV. Single-shot measurements have been used to measure the exact point of maximum compression. Analysis from the proof of concept results last year, and initial results from the new measurements this year are discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW095  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW096 Development of Supersonic Gas-Sheet-Based Beam Profile Monitors electron, photon, background, monitoring 2717
 
  • H.D. Zhang, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • M. Ady, J. Glutting, O.R. Jones, T. Marriott-Dodington, S. Mazzoni, A. Rossi, G. Schneider, R. Veness
    CERN, Geneva, Switzerland
  • P. Forck, S. Udrea
    GSI, Darmstadt, Germany
  • A. Salehilashkajani, C.P. Welsch, H.D. Zhang
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: HL-LHC project funded by STFC and CERN, and the STFC Cockcroft core grant No. ST/G008248/1.
Non-destructive beam profile monitoring is very desirable, essentially for any particle accelerator but particularly for high-energy and high-intensity machines. Supersonic gas jet-based monitors, detecting either the ionization or fluorescence of a gas sheet interacting with the primary beam to be characterized, allow for minimally invasive measurements. They can also be used over a wide energy range, from keV to TeV beams. This contribution gives an overview of the jet-based ionization and fluorescence beam profile monitors which have been developed, built and tested at the Cockcroft Institute. It discusses gas sheet generation, vacuum considerations, choice of gas species and detection methods.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW096  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW099 Development of a Beam Halo Monitor synchrotron-radiation, synchrotron, electron, optics 2721
 
  • V.G. Dudnikov, R.P. Johnson, M. Popovic
    Muons, Inc, Illinois, USA
  • M.A. Cummings
    Northern Illinois University, DeKalb, Illinois, USA
  • R.M. Thurman-Keup
    Fermilab, Batavia, Illinois, USA
 
  Our innovative approach is to design the Beam Halo Monitor, where beam induced synchrotron radiation will be used to monitor the beam Halo. This involves an original scheme of light collection using a coronograph for measuring beam halo.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW099  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW103 Synchrotron Radiation Beam Diagnostics at IOTA - Commissioning Performance and Upgrade Efforts electron, optics, experiment, detector 2732
 
  • N. Kuklev, Y.K. Kim
    University of Chicago, Chicago, Illinois, USA
  • J.D. Jarvis, A.L. Romanov, J.K. Santucci, G. Stancari
    Fermilab, Batavia, Illinois, USA
 
  Funding: Work supported by National Science Foundation award PHY-1549132, the Center for Bright Beams. Fermi Research Alliance operates Fermilab under Contract DE-AC02-07CH11359 with the US Dept. of Energy.
The Integrable Optics Test Accelerator is a research electron and proton storage ring recently commissioned at the Fermilab Accelerator Science and Technology facility. A key part of its beam diagnostics suite are synchrotron radiation monitors, used for measuring transverse beam profile, position, and intensity. In this paper, we report on the performance and uses of this system during the year 1 run. We demonstrate sub-100nm statistical beam position uncertainty and high dynamic range from 109 electrons down to a single electron. Commissioning challenges and operational issues are discussed. We conclude by outlining current upgrade efforts, including improved modularity, small emittance measurements, and a multi-anode photomultiplier system for turn-by-turn acquisition.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW103  
About • paper received ※ 15 May 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPGW110 Feasibility Study of Beam Profile Measurements Using Interferometer and Diffractometer Techniques for ALS-U electron, synchrotron, storage-ring, lattice 2752
 
  • C. Sun, S. De Santis, D. Filippetto, F. Sannibale, C. Steier
    LBNL, Berkeley, California, USA
 
  Funding: Work supported by the Director Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
ALS-U is an ongoing upgrade of Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. The upgraded ALS will replace the existing Triple-Bend Achromat (TBA) storage ring lattice with a compact Multi-Bend Achromat (MBA) lattice. This MBA technology allows us to tightly focus electron beams down to about 10 μm to reach diffraction limit in a soft x-ray region. The beam size measurement is a challenging task for this tightly focused beam. The interferometer technique with visible light from synchrotron radiation has been developed in many facilities to measure their beam size at a micrometer-level accuracy. In this paper, we will present the feasibility study of this technique for the ALS-U storage ring beam size measurement.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW110  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPRB025 High Density Mapping for Superconducting Cavities cavity, cryogenics, status, operation 2860
 
  • Y. Iwashita, H. Tongu
    Kyoto ICR, Uji, Kyoto, Japan
  • Y. Fuwa
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • R.L. Geng
    JLab, Newport News, Virginia, USA
  • H. Hayano
    KEK, Ibaraki, Japan
 
  High density mapping system for superconducting cavities are under development. Testing on the stiffener X-ray mapping system at JLAB showed consistent results in comparison with simultaneously taken GM tube or ion chamber output signals. The system provides better visi-bility as shown by data briefly reported here. In addition to the temperature and the X-ray mapping, a sensitive magnetic field mapping system with high spatial density is also under development. The magnetic field sensor is AF755B, whose operations at cryogenic temperatures are already reported by other group. Our development status using the magnetic field sensor will be reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB025  
About • paper received ※ 19 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPRB054 Design of the Multiplexing Optical Measurement System for a Pre-bunched THz Free Electron Laser laser, detector, FEL, electron 2931
 
  • Y.K. Zhao, W. Li, B.G. Sun, Y.G. Tang, F.F. Wu, T.Y. Zhou
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  Funding: Work supported by the the Fundamental Research Funds for the Central Universities (WK2310000080, WK2310000057), and the National Science Foundation of China (11705203, 11575181)
A new and compact a pre-bunched terahertz (THz) free electron laser (FEL) at the National Synchrotron Radiation Laboratory, University of Science and Technology of China is being constructed and aims to generate the tunable radiation frequency ranges from 0.5 THz to 5 THz at 11-18 Mev electron energy. This system is expected to use for imaging, basic researches as well as industrial applications as a result of the significant merits of simple, compact and cost-effective. Due to the THz laser measurement system plays an important part in the pre-bunched THz FEL facility. Therefore, a multiplexing THz laser sensing measurement system model is developed for measuring the output laser power and the optical spectrum of THz radiation with the excellent advantages of robustness, high sensitivity and low-cost in this paper.
Corresponding author (email: tiany86@ustc.edu.cn)
Corresponding author (email: wufangfa@ustc.edu.cn)
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB054  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPRB059 Dark Current Analysis at CERN’s X-band Facility operation, electron, ECR, linac 2944
 
  • D. Banon-Caballero, M. Boronat, V. Sánchez Sebastián, A. Vnuchenko
    IFIC, Valencia, Spain
  • N. Catalán Lasheras, S. Pitman, M. Widorski, W. Wuensch, V. del Pozo Romano
    CERN, Meyrin, Switzerland
  • A. Faus-Golfe
    LAL, Orsay, France
  • B. Gimeno
    UVEG, Burjasot (Valencia), Spain
  • T.G. Lucas, M. Volpi
    The University of Melbourne, Melbourne, Victoria, Australia
  • W.L. Millar
    Lancaster University, Lancaster, United Kingdom
  • J. Paszkiewicz
    University of Oxford, Oxford, United Kingdom
 
  Dark current is particularly relevant during operation in high-gradient linear accelerators. Resulting from the capture of field emitted electrons, dark current produces additional radiation that needs to be accounted for in experiments. In this paper, an analysis of dark current is presented for four accelerating structures that were tested and conditioned in CERN’s X-band test facility for CLIC. The dependence on power, and therefore on accelerating gradient, of the dark current signals is presented. The Fowler-Nordheim equation for field emission seems to be in accordance with the experimental data. Moreover, the analysis shows that the current intensity decreases as a function of time due to conditioning, but discrete jumps in the dark current signals are present, probably caused by breakdown events that change the emitters’ location and intensity.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB059  
About • paper received ※ 10 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPRB073 CW Room Temperature Accelerating Structures impedance, operation, electron, SRF 2990
 
  • S.P. Antipov, P.V. Avrakhov, E. Gomez, S.V. Kuzikov
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • A.A. Vikharev
    IAP/RAS, Nizhny Novgorod, Russia
 
  To this day CW linear electron accelerators were based only on expensive and bulky (embedded in a cryostat) superconducting accelerating structures. CW regime can in principle be realized with normal conducting structures provided the shunt impedance is high. Such structures can be designed using dielectrics (ultra-pure ceramics in C-band and diamond in mm-waves) with ultra-low loss tangent (~10-6). The use of dielectrics allows to concentrate the electromagnetic energy density in the dielectric region and thus minimize fields and ohmic loss on metallic walls. The thermal loss in dielectric can be relatively low given the loss tangent is small. We report here the design of structures with shunt impedance on the order of 104 MOhm/m, which is several orders of magnitude higher than shut impedance in copper structures in GHz and THz range. High shunt impedance makes it possible to accelerate electrons to 1 MeV using kW-level CW RF sources like magnetrons in C-band and gyrotrons in THz range. Such CW accelerators will find applications in sterilization, food irradiation, industrial radiography and cargo inspection.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB073  
About • paper received ※ 21 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPRB106 Simulation of the Transition Radiation Transport Through an Optic System simulation, electron, optics, diagnostics 3059
 
  • M. Marongiu, A. Mostacci, L. Palumbo
    Sapienza University of Rome, Rome, Italy
  • F.G. Bisesto, E. Chiadroni, G. Di Pirro, G. Franzini, A. Giribono, V. Shpakov, A. Stella, A. Variola
    INFN/LNF, Frascati, Italy
  • A. Cianchi
    Università di Roma II Tor Vergata, Roma, Italy
  • A. Mostacci, L. Palumbo
    INFN-Roma, Roma, Italy
 
  Optical Transition Radiation (OTR) screens are widely used for beam profile measurements. The radiation is emitted when a charged particle beam crosses the boundary between two media with different optical properties. The main advantages of OTR are the instantaneous emission process allowing fast single shot measurements (i.e. bunch by bunch measurements in a multi bunch machine), and the good linearity with the beam charge (if coherent effects can be neglected). Furthermore, OTR angular distribution strongly depends on beam energy. Since OTR screens are typically placed in several positions along the Linac to monitor beam envelope, one may perform a distributed energy measurement along the machine: this will be useful, for instance, during the commissioning phase of a machine. This paper deals with the studies of an algorithm to optimize the generation and the transport of the transition radiation through an optic system using the simulation tool Zemax. The algorithm, in combination with a particle tracking code (i.e. Elegant), will allow to simulate the radiation generated by a beam and, so, to take into account beam divergence and energy spread or chromatic effects in the optic system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB106  
About • paper received ※ 08 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPRB116 X-ray Pinhole Camera for Emittance Measurements in Solaris Storage Ring emittance, storage-ring, photon, diagnostics 3084
 
  • A. Kisiel, A.M. Marendziak, M. Ptaszkiewicz, A.I. Wawrzyniak
    Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
 
  X-ray pinhole camera is widely used system for the transverse beam profile measurement and emittance feedback. However this method is predominantly applied to the middle and high energy storage rings. At Solaris storage ring with the nominal energy of 1.5 GeV, the design of the beamline was modified to provide sufficient X-ray photon flux for proper imaging. The successful installation and commissioning of the X-ray pinhole beamline allows now to measure the emittance and helps in proper 3rd harmonic cavities tuning against the coupled bunch mode instabilities. The paper describes the design details, simulations and measurement results obtained during the beamline operation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB116  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPTS015 Synchronous Measurements of Electron Bunches Under the Influence of the Microbunching Instability synchrotron, bunching, simulation, storage-ring 3119
 
  • M. Brosi, T. Boltz, E. Bründermann, S. Funkner, B. Kehrer, A.-S. Müller, M.J. Nasse, G. Niehues, M.M. Patil, P. Schreiber, P. Schönfeldt, J.L. Steinmann
    KIT, Karlsruhe, Germany
 
  Funding: This work has been supported by the German Federal Ministry of Education and Research (Grant No. 05K16VKA). We acknowledge the support by the Helmholtz International Research School for Teratronics.
The microbunching instability is a longitudinal collective instability which occurs for short electron bunches in a storage ring above a certain threshold current. The instability leads to a charge modulation in the longitudinal phase space. The resulting substructures on the longitudinal bunch profile vary over time and lead to fluctuations in the emitted power of coherent synchrotron radiation (CSR). To study the underlying longitudinal dynamics on a turn-by-turn basis, the KIT storage ring KARA (Karlsruhe Research Accelerator) provides a wide variety of diagnostic systems. By synchronizing the single-shot electro-optical spectral decoding setup (longitudinal profile), the bunch-by-bunch THz detection systems (THz power) and the horizontal bunch size measurement setup (energy spread), three important properties of the bunch during this instability can be measured at every turn for long time scales. This allows a deep insight into the dynamics of the bunch under the influence of the microbunching instability. This contribution will discuss effects like the connection between the emitted CSR power and the deformations in the longitudinal bunch profile on the time scale of the instability.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS015  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPTS017 Synchrotron Radiation Module in OCELOT Toolkit electron, undulator, simulation, FEL 3127
 
  • S. Tomin, G. Geloni
    EuXFEL, Hamburg, Germany
 
  Synchrotron radiation (SR) sources based on single-pass accelerators (e.g. linacs, plasma accelerators) have to cope with electron beams with a rather complicated phase space distribution. In this case, the convolution method usually employed to calculate radiation properties can give poor accuracy or be not applicable at all. Moreover, dynamical effects can also play a role in the emission mechanism. This happens when the beam parameters (e.g. beam current) significantly change during the passage through the undulator. In this work, we present a dedicated SR module of the OCELOT toolkit, which is well suited to deal with these situations.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS017  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPTS051 Comparison of Electron Cloud Build-Up Simulations Against Heat Load Measurements for the LHC Arcs With Different Beam Configurations electron, simulation, operation, synchrotron-radiation 3232
 
  • G. Skripka, G. Iadarola, L. Mether, G. Rumolo, E.G.T. Wulff
    CERN, Meyrin, Switzerland
  • P. Dijkstal
    PSI, Villigen PSI, Switzerland
 
  Electron cloud effects are among the main performance limitations for the operation of the Large Hadron Collider (LHC) with 25 ns bunch spacing. A large number of electrons impacting on the beam screens of the cold magnets induces significant heat load, reaching values close to the full cooling capacity available from the cryogenic system. Interestingly, it is observed that parts of the machine that are by design identical show very different heat loads. We used numerical simulations to investigate the possibility that these differences are induced by different surface properties, in particular maximum Secondary Electron Yield (SEY) for the different cryomagnets. Using the PyECLOUD code, the electron cloud build-up was simulated assuming different values of SEY in the LHC cold magnets. Comparing the measured heat loads to the simulation results for the 25 ns beams at 450 GeV we have identified the SEY values that match the observations in these conditions. These SEY values were found to be in good agreement with the heat loads measured with different beam configurations (changing the bunch pattern, the bunch intensity and the beam energy).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS051  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPTS058 BDSIM: Recent Developments and New Features Beyond V1.0 simulation, detector, site, experiment 3259
 
  • L.J. Nevay, A. Abramov, J. Albrecht, S. E. Alden, S.T. Boogert, H. Garcia Morales, S.M. Gibson, W. Shields, S.D. Walker
    JAI, Egham, Surrey, United Kingdom
  • J. Snuverink
    PSI, Villigen PSI, Switzerland
 
  BDSIM is a program that creates a 3D model of an accelerator from an optical beam line description using a suite of high energy physics software including Geant4, CLHEP and ROOT. In one single simulation the passage of particles can be tracked accurately through an accelerator including the interaction with the accelerator material and subsequent secondary radiation production and transport. BDSIM is regularly used to simulate beam loss and energy deposition as well as machine detector interface studies. In this paper we present the latest developments beyond BDSIM V1.0 added for ongoing studies. For simulation of collimation systems several new additions are described including new element geometry, enhanced sensitivity and output information. The output has been further enhanced with aperture impact information and dose information from scoring meshes. As well as supporting the full suite of Geant4 physics lists, a new user interface is described allowing custom physics lists and user components to be easily included in BDSIM. New undulator, crystal collimator and wire-scanner elements are also described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS058  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPTS102 Helical Wiggler Model for Fast Tracking wiggler, electron, optics, undulator 3356
 
  • W.F. Bergan, V. Khachatryan, D. L. Rubin
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: NSF-1734189 DGE-1650441
In order to test the process of Optical Stochastic Cooling (OSC) at the Cornell Electron Storage Ring (CESR), we plan to use helical wigglers as both the pickup and kicker, since the required radiation wavelength of 800nm can be achieved with lower magnetic field strength in helical as compared to planar wigglers. In order to simulate the lattice with such wigglers, it is useful to be able to model the effect of the wiggler on the optics without resorting to direct tracking, which is time-consuming and so ill-suited for the repeated evaluations necessary in running an optimizer. We generate a Taylor map to third order for this element using analytic field expressions, enabling easy determination of the effects of such an element on linear and nonlinear optics. This model is compared with the results of direct tracking and shows good agreement.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS102  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPTS104 Synchrotron Radiation Reflections in the CLIC Beam Delivery System photon, detector, collider, synchrotron 3363
 
  • D. Arominski, A. Latina, A. Sailer, D. Schulte
    CERN, Meyrin, Switzerland
 
  Synchrotron radiation (SR) reflection is an important issue for future linear colliders. High fluxes of the SR might impact the performance of the detector, through irradiation of the forward luminosity and beam quality calorimeters or of the innermost layers of the vertex detector. The photon reflections depend on the beam pipe apertures’ size, their shape, and materials used with various surface roughness. In this work, we present a study of SR including reflection for the 380 GeV and 3 TeV beam parameters and optics of the Compact Linear Collider’s Final Focus System. The simulations of the SR reflections using the Synrad+ software are presented and the impact on the detector is discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS104  
About • paper received ※ 29 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPTS106 Accelerator Optimization using Big Data Science Techniques plasma, experiment, electron, proton 3370
 
  • C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: This project has received funding from STFC under grant reference ST/P006752/1.
Managing, analyzing and interpreting large, complex datasets and high rates of data flow is a growing challenge for many areas of science and industry. At particle accelerators and light sources, this data flow occurs both, in the experiments as well as the machine itself. The Liverpool Big Data Science Center for Doctoral Training (LIV. DAT) was established in 2017 to tackle the challenges in Monte Carlo modelling, high performance computing, machine learning and data analysis across particle, nuclear and astrophysics, as well as accelerator science. LIV. DAT is currently training 24 PHD students, making it one of the largest initiatives of this type in the world. This contribution presents research results obtained to date in projects that focus on the application of big data techniques within accelerator R&D.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS106  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPTS107 Designing the European Spallation Source Tuning Dump Beam Imaging System proton, target, linac, optics 3374
 
  • M.G. Ibison, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • E. Adli, G. Christoforo, H. Gjersdal
    University of Oslo, Oslo, Norway
  • M.G. Ibison, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
  • T.J. Shea, C.A. Thomas
    ESS, Lund, Sweden
 
  Funding: In-Kind Agreement, ESS/Norway
The first section of the European Spallation Source (ESS) to receive high-energy protons when live operation begins will be the Tuning Dump beam-line. The dump line will be used during accelerator commissioning to tune the linac, and must accept the full range of ESS energies up to 2 GeV, from 5µs probe pulse to full 2.86ms pulse length, and beam sizes up to the 250 mm limit of the physical aperture, although the allowed pulse rate will be restricted by the thermal capacity of the dump. An imaging system has been developed to view remotely the transverse beam profile in the section immediately before the dump entrance, using insertable scintillator screens. This contribution presents the principal design parameters for this system, with particular reference to the techniques used in assessing the radiation and thermal environments and their impact on the selection of locations for the imaging cameras, and the specification of the mechanical screen actuators. The predicted optical performance of the system is also summarised.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS107  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THXPLS1 Review of Ion Therapy Machine and Future Perspective synchrotron, operation, controls, proton 3391
 
  • K. Noda
    NIRS, Chiba-shi, Japan
 
  Cancer therapy with ion beams presents several advantages as compared to proton therapy or conventional radiation therapy but its diffusion is limited by the size and cost of the accelerator facility. The ion therapy facilities are presently in operation have generated important developments in particular to the gantry, beam delivery technique, and beam scanning system, while new treatment facilities being planned in United States, Europe, and Asia. This talk will present the current status of this field, as well as the future perspective.  
slides icon Slides THXPLS1 [26.303 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THXPLS1  
About • paper received ※ 13 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THYYPLS3 A Remote-Controlled Robot-Car in the TPS Tunnel photon, controls, operation, laser 3435
 
  • T.Y. Lee, B.Y. Chen, T.W. Hsu, B.Y. Huang, C.H. Kuo, W.Y. Lin
    NSRRC, Hsinchu, Taiwan
 
  A remote-controlled robot-car named ’PhotonBot’ was put into the TPS accelerator tunnel and is equipped with a 360 degrees LiDAR for SLAM and navigation, two cameras for perception and first-person view, and a thermal imaging system. The robot can be remotely controlled and can send data to a remote PC through Wi-Fi. With SLAM, it can go more freely without being restricted to a designated path. In order to ensure it can work continuously, there is a wireless charging station in case of a low battery.  
slides icon Slides THYYPLS3 [18.013 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THYYPLS3  
About • paper received ※ 09 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMP002 Optics Design and Beam Dynamics Simulation for a VHEE Radiobiology Beam Line at PRAE Accelerator linac, gun, electron, optics 3444
 
  • A. Faus-Golfe, B. Bai, Y. Han, C. Vallerand
    LAL, Orsay, France
  • R. Delorme, Y. Prezado
    IMNC, Orsay, France
  • M. Dosanjh
    CERN, Meyrin, Switzerland
  • P. Duchesne
    IPN, Orsay, France
  • V. Favaudon, C. Fouillade, P.M. Poortmans, F. Pouzoulet
    Institut Curie - Centre de Protonthérapie d’Orsay, Orsay, France
 
  The Platform for Research and Applications with Electrons (PRAE) is a multidisciplinary R&D facility gathering subatomic physics, instrumentation, radiobiology and clinical research around a high-performance electron accelerator with beam energies up to 70 MeV. In this paper we report the complete optics design and performance evaluation of a Very High Energy Electron (VHEE) innovative radiobiology study, in particular by using Grid mini-beam and FLASH methodologies, which could represent a major breakthrough in Radiation Therapy (RT) treatment modality.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP002  
About • paper received ※ 27 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMP008 Feasibility Study on Mo-99 Production Using Hybrid Method Based on High Power Electron Accelerator target, neutron, electron, photon 3462
 
  • A. Taghibi Khotbeh-Sara, F. Rahmani
    KNTU, Tehran, Iran
  • F. Ghasemi
    NSTRI, Tehran, Iran
  • H. Khalafi
    AEOI, Tehran, Iran
  • M. Mohseni Kejani
    Shahid Beheshti University, Tehran, Iran
 
  In this study, the idea 99Mo production using hybrid method based on electron accelerator has been pre-sented. Two different main production channels of 100Mo(γ,n)99Mo and 98Mo(n,γ)99Mo can be used for 99Mo production in this system. By considering high power Linac (30 MeV, 1 mA in average beam current) and one-stage approach, the calculation of 100Mo(γ,n)99Mo reactions in the optimized 100Mo target in two different designs (strip and disc) has been simu-lated. It is predicted that about 61 and 53 Ci of 99Mo activity per 24-hour irradiation on the strip target and the disc plates can be achieved, respectively. The threshold energy of photoneutron at 100Mo is about 9 MeV, so a large part of bremsstrahlung photons cannot participate in photoneutron reaction. For feasibility study, new hybrid approach has been tested by 10 MeV Rhodotron. Due to the low threshold of photo-neutron in deuteron (about 2.2 MeV) and significant low energy photons in 100Mo, photoneutron flux is available. So, Molybdenum target in heavy water Tank increases the production yield of 99Mo using neutron absorption reaction in 98Mo. The total activity of 99Mo has been predicted about 0.23 Ci per 24 hours e-beam irradiation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP008  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMP011 Optics and Commissioning of the CNAO Experimental Beam Line experiment, proton, MMI, optics 3472
 
  • S. Savazzi, E. Bressi, L. Falbo, V. Lante, C. Priano, M. G. Pullia
    CNAO Foundation, Pavia, Italy
  • P. Meliga
    University of Pavia, Pavia, Italy
 
  CNAO (National Centre for Oncological Hadronthera-py) in Pavia is one of the six centres worldwide in which hadrontherapy is administered with both protons and carbon ions. The main accelerator is a 25 m diameter synchrotron designed to accelerate carbon ions up to an energy of 400 MeV/u and protons up to an energy of 250 MeV. It was designed with three treatment rooms and an ’experimental room’ where research can be carried out. The room itself was built since the beginning, but the beam line was planned to be installed in a second moment in order to give priority to treatments. The beam line of the experimental room (XPR) is designed to be "general purpose", for research activities in different fields. In October 2018 the installation phase of the line was started and it ended in January 2019. In this paper a short description of the optics layout and commissioning strategy is given.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP011  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMP012 New Industrial Application Beamline for the cERL in KEK target, electron, linac, vacuum 3475
 
  • Y. Morikawa, K. Haga, M. Hagiwara, K. Harada, N. Higashi, T. Honda, Y. Honda, M. Hosumi, Y. Kamiya, R. Kato, H. Kawata, Y. Kobayashi, H. Matsumura, C. Mitsuda, T. Miura, T. Miyajima, S. Nagahashi, N. Nakamura, K.N. Nigorikawa, T. Nogami, T. Obina, H. Sagehashi, H. Sakai, M. Shimada, M. Tadano, R. Takai, H. Takaki, O. A. Tanaka, Y. Tanimoto, A. Toyoda, T. Uchiyama, A. Ueda, K. Umemori, M. Yamamoto
    KEK, Ibaraki, Japan
 
  The new beam line for the industrial applications is constructed at the cERL (compact Energy Recovery LINAC) in KEK. In these applications, only north straight sections of cERL consisting of injector and main LINAC will be used. The test for the radio isotope production and electron beam irradiation for the materials are firstly planned with very small beam current without energy recovery.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP012  
About • paper received ※ 11 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMP025 Modern Heavy Ion Based Test Facilities For Spacecrafts Electronics Qualification detector, heavy-ion, monitoring, electron 3497
 
  • P.A. Chubunov
    ISDE, Moscow, Russia
  • V.S. Anashin
    United Rocket and Space Corporation, Institute of Space Device Engineering, Moscow, Russia
  • I.V. Kalagin, S.V. Mitrofanov, V.A. Skuratov
    JINR, Dubna, Moscow Region, Russia
 
  All spacecraft electronics should be subject to radiation hardness qualifications. For modern semiconductor technologies, individual high-energy particles of outer space are the greatest danger, causing upsets and failures in satellite equipment. For ground tests at single event effects, heavy ion-based modeling facilities are used. The report describes the test benches used for testing space-based electronics, created on the basis of the U-400, U-400M ion accelerators in the FLNR JINR (Dubna, Russia) at the request of ISDE (Moscow, Russia).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP025  
About • paper received ※ 18 May 2019       paper accepted ※ 26 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMP026 Mobile Accelerator Based on Ironless Pulsed Betatron for Dynamic Objects Radiographing betatron, electron, ion-source, target 3500
 
  • V.A. Fomichev, A.A. Chinin, S.G. Kozlov, Yu.P. Kuropatkin, V.I. Nizhegorodtsev, I.N. Romanov, K.V. Savchenko, V.D. Selemir, O.A. Shamro, E.V. Urlin
    RFNC-VNIIEF, Sarov, Nizhniy Novgorod region, Russia
 
  The paper concerns a mobile accelerator based on the ironless pulsed betatron. The accelerator has a possibility to obtain up to three frames in a single pulse and is aimed to radiograph dynamic objects with a large optical thickness. The block diagram of the accelerator, the temporal diagram of its separate systems operation and oscillograms of the betatron output parameters are provided. The testing powering in a single frame mode was carried out in 2018. The capacitance of the storage of the betatron electromagnet pulsed powering system that defines the electron beam energy was equal to 1800 μF. The following test results have been obtained. The thickness of the lead test object examined with X-rays reached 140 mm at 4 m from the tantalum target of the betatron. The full width of the output gamma pulse at half maximum in a single frame mode was equal to 120 ns; the dimension of the radiation source was 6 mm x 3 mm; the dimension of the tantalum target was 6 mm x 6 mm. The application of these accelerators within the radiographic complex* enables the optimization of the hydrodynamic experiments geometry resulting in the increase of the test efficiency.
* Pat. 2548585 C1 RU MPK G03B 42/02. D.I. Zenkov and others. «Mobile radiographic complex and radiation source of betatron type for radiographic complex» (in Russian), 2015.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP026  
About • paper received ※ 25 April 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMP027 Concept of Radiographic Complex Based on Ironless Pulsed Betatrons for Small-Angle Tomography betatron, experiment, collimation, ion-source 3503
 
  • O.A. Shamro, A.A. Chinin, V.A. Fomichev, Yu.P. Kuropatkin, V.I. Nizhegorodtsev, K.V. Savchenko, V.D. Selemir
    RFNC-VNIIEF, Sarov, Nizhniy Novgorod region, Russia
 
  The active research complexes intended for the radiography of dynamic objects with a high optical density are reviewed. The concept of a multi-beam radiographic complex for a small-angle tomography based on ironless pulsed betatrons is proposed*. It is possible to use up to 18 compact facilities in a complex; they are located in three horizontal planes. The test object is placed in the explosion-proof chamber. Each facility consists of two typical units: an accelerator unit, and a unit of the electromagnet pulsed powering system. The output parameters of the facility are the maximum translucent capacity of 200 mm of the lead at 1 m from the betatron target, the resolution of less than 1 mm, the gamma-pulse full width at half maximum of 100 ns in a single frame mode, the gamma-pulse full width at half maximum of 150 ns in a three-frame mode. The complex will be able to obtain up to 54 frames in one hydrodynamic experiment at the operation of each facility in a three-frame mode. The complex is compact. Its diameter with a service area will be 20 m.
* Pat. 2515053 С1 RU МPK G03B 42/02. Yu.P. Kuropatkin, others. «Method of Radiograph. Image Form. of Fast Processes in Inhomogeneity and Radiograph. Complex for its Implementation», 2014.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP027  
About • paper received ※ 25 April 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMP033 Beam Characterisation Using MEDIPIX3 and EBT3 Film at the Clatterbridge Proton Therapy Beamline proton, detector, simulation, experiment 3510
 
  • J.S.L. Yap, J. Resta-López, R. Schnuerer, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • N.J.S. Bal
    ASI, Amsterdam, The Netherlands
  • N.J.S. Bal, M. Fransen, F. Linde
    NIKHEF, Amsterdam, The Netherlands
  • A. Kacperek
    The Douglas Cyclotron, The Clatterbridge Cancer Centre NHS Foundation Trust, Wirral, United Kingdom
  • J.L. Parsons
    Cancer Research Centre, University of Liverpool, Liverpool, United Kingdom
  • J. Resta-López, R. Schnuerer, C.P. Welsch
    The University of Liverpool, Liverpool, United Kingdom
 
  Funding: EU FP7 grant agreement 215080, H2020 Marie Skłodowska-Curie grant agreement No 675265 - Optimization of Medical Accelerators (OMA) project and the Cockcroft Institute core grant STGA00076-01.
The Clatterbridge Cancer Centre (CCC) in the UK is a particle therapy facility providing treatment for ocular cancers using a 60 MeV passively scattered proton therapy beam. A model of the beamline using the Monte Carlo Simulation toolkit Geant4 has been developed for accurate characterisation of the beam. In order to validate the simulation, a study of the beam profiles along the delivery system is necessary. Beam profile measurements have been performed at multiple positions in the CCC beam line using both EBT3 GAFchromic film and Medipix3, a single quantum counting chip developed specifically for medical applications, typically used for x-ray detection. This is the first time its performance has been tested within a clinical, high proton flux environment. EBT3 is the current standard for conventional radiotherapy film dosimetry and was used to determine the dose and for correlation to fluence measured by Medipix3. The count rate linearity and doses recorded with Medipix3 were evaluated across the full range of available beam intensities, up to 3.12 x 1010 protons/s. The applicability of Medipix3 for proton therapy dosimetry is discussed and compared against the performance of EBT3.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP033  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMP038 Collaborative Strategies for Meeting the Global Need for Cancer Radiation Therapy Treatment Systems linac, electron, vacuum, permanent-magnet 3526
 
  • M. Dosanjh, P. Collier, I. Syratchev, W. Wuensch
    CERN, Meyrin, Switzerland
  • A. Aggarwal
    KCL, London, United Kingdom
  • D. Angal-Kalinin, P.A. McIntosh, B.L. Militsyn
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • R. Apsimon
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • S.T. Boogert
    Royal Holloway, University of London, Surrey, United Kingdom
  • G. Burt
    Lancaster University, Lancaster, United Kingdom
  • N. Coleman, D.A. Pistenmaa
    ICEC, Washington, DC, USA
  • A.W. Cross
    USTRAT/SUPA, Glasgow, United Kingdom
  • I.V. Konoplev, S.L. Sheehy
    JAI, Oxford, United Kingdom
 
  The idea of designing affordable equipment and developing sustainable infrastructures for delivering radiation treatment for patients with cancer in countries that lack resources and expertise stimulated a first International Cancer Expert Corps (ICEC) championed, CERN-hosted workshop in Geneva in November 2016. Which has since been followed by three additional workshops involving the sponsorship and support from UK Science and Technology Facilities Council (STFC). One of the major challenges in meeting this need to deliver radiotherapy in low- and middle-income countries (LMIC) is to design a linear accelerator and associated instrumentation system which can be operated in locations where general infrastructures and qualified human resources are poor or lacking, power outages and water supply fluctuations can occur frequently and where climatic conditions might be harsh and challenging. In parallel it is essential to address education, training and mentoring requirements for current, as well as future novel radiation therapy treatment (RTT) systems.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP038  
About • paper received ※ 11 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMP041 A Comparative Study of Biological Effects of Electrons and Co-60 Gamma Rays on pBR322 Plasmid DNA electron, experiment, controls, proton 3533
 
  • K.L. Small, R.M. Jones
    UMAN, Manchester, United Kingdom
  • D. Angal-Kalinin, M. Surman
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • A. Chadwick, N.T. Henthorn, K. Kirkby, M.J. Merchant, R. Morris, E. Santina
    The Christie NHS Foundation Trust, Manchester, United Kingdom
  • R. Edge
    Dalton Cumbrian Facility, University of Manchester, Cumbria, United Kingdom
  • R.J. Smith
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Very High-Energy Electron (VHEE) therapy is a rapidly developing field motivated by developments in high-gradient linacs. Advantages include sufficient penetration (>30 cm) for treatment of deep-seated tumours, measured insensitivity to inhomogeneities and rapid delivery time, making VHEE viable for treatment of heterogeneous regions, e.g. lung or bowel. Researchers at the University of Manchester and CERN have routinely produced accelerating gradients of ~100 MeV/m for the CLIC project. Suitable modification can result in a high gradient medical linac producing 250 MeV electrons within a treatment room. Radiobiological research for VHEE is vital to understand its use in radiotherapy and how it compares with conventional modalities. The goal of radiotherapy is to destroy tumour cells while sparing healthy cells, primarily by damaging DNA within the cancer cell. The study aim is to understand the fundamental interactions between VHEE and biological structures through plasmid irradiation studies - both computational, using the Monte Carlo GEANT4-DNA code, and experimental. Plasmid irradiation experiments have been carried out at using Co-60 gammas at the Dalton Cumbrian Facility and using 6-15 MeV electrons at the Christie NHS Foundation Trust to determine the type and quantity of damage caused to DNA by electron irradiation. These experiments are a world first in VHEE radiobiology, with further studies planned at higher energies using the CLARA and CLEAR facilities at Daresbury and CERN. These studies will also consider the effective dose range of VHEE with energy, as well as implications of damage on DNA. Research into this area of radiotherapy can provide a valuable addition to tools currently available to physicians in the fight against cancer.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP041  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMP044 Radiation Hard Sensor for Reactor Applications laser, GUI, timing, detector 3545
 
  • R.J. Abrams, M.A. Cummings, R.P. Johnson, T.J. Roberts
    Muons, Inc, Illinois, USA
  • D.M. Kaplan
    Illinois Institute of Technology, Chicago, Illinois, USA
 
  A novel method of measuring temperature of the coolant inside a reactor core is presented. The method, which is both standoff and non-invasive, is based on the interaction between an ultrasonic pulse and a delayed light pulse in the coolant. In the interaction, the light pulse, which is scattered backward by Brillouin scattering, is frequency-shifted. The frequency shift is dependent on the temperature and other parameters of the coolant. The light pulses and the ultrasound pulses are generated and detected outside of the core.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPMP044  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPGW015 Proposed Beam Test of a Transverse Gradient Undulator at the SINBAD Facility at DESY undulator, linac, electron, experiment 3609
 
  • R. Rossmanith, A. Bernhard, K. Damminsek, J. Gethmann, S. Richter
    KIT, Karlsruhe, Germany
  • R.W. Aßmann, F. Burkart, U. Dorda, F. Jafarinia, B. Marchetti
    DESY, Hamburg, Germany
  • M. Kaluza
    IOQ, Jena, Germany
 
  While Laser Plasma Accelerators produce beams with the high output energy required for FELs, up to now the relatively high energy spread has prohibited FEL lasing. Therefore it was proposed to replace the normal FEL undulators by Transverse Gradient Undulators (TGUs). For a first, small scale test of the TGU concept, a 40 period prototype high gradient superconductive TGU was built at KIT and will be tested with beam at the ARES-linac in the new accelerator test facility SINBAD (Short Innovative Bunches and Accelerators at Desy) at DESY. The proposed tests are summarized in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW015  
About • paper received ※ 07 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPGW036 Development of Supercontinuum Light Production System Using Er Fiber Laser for Pulse Radiolysis* laser, experiment, electronics, electron 3660
 
  • T. Uchida, S. Hanai, K. Sakaue, M. Washio
    Waseda University, Tokyo, Japan
 
  Pulse radiolysis is one of the methods to elucidate radiation chemical reactions. In order to elucidate that, not only high temporal resolution, but also a light source with a broad spectrum band is required. A Xe flash lamp is mentioned as a light source having a broad spectrum band. However, in measurement using a Xe flash lamp, the time resolution is limited to the nanosecond order. In this research, we have developed supercontinuum light as a light source that enables picosecond time resolution and has a broader spectrum band. In this paper, we developed a light source using an Er doped fiber laser for pulse radiolysis measurement, and report the results and future prospects here.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW036  
About • paper received ※ 15 May 2019       paper accepted ※ 24 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPGW042 Applications of Compact Laser Plasma Accelerator (CLAPA) Beamline in Peking University proton, laser, acceleration, plasma 3676
 
  • D.Y. Li, J.E. Chen, Y.X. Geng, X.Y. Hu, C.C. Li, Q. Liao, C. Lin, H.Y. Lu, W.J. Ma, M.J. Wu, X.H. Xu, X.Q. Yan, T. Yang, Y.Y. Zhao, J.G. Zhu, K. Zhu
    PKU, Beijing, People’s Republic of China
 
  Proton beam with energies less than 10 MeV, <1% energy spread, several to tens of pC charge can be stably produced and transported in Compact LAser Plasma Accelerator (CLAPA) at Peking University. The CLAPA beam line is an object-image point analysing system, which ensures the transmission efficiency and energy selection accuracy for proton beams with initial large divergence angle and energy spread. A spread-out Bragg peak (SOBP) is produced with high precision beam control, which is essential for cancer therapy. Other primary application experiments based on laser-accelerated proton beam have also been carried out, such as proton radiograph, stress testing for tungsten, irradiation of semi-conductor sensor to simulate the space irradiation environment and so on.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW042  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPGW048 Temporal Characterization of Electron Bunches From Self-Injection and Ionization Injection in a Laser Wakefield Accelerator injection, electron, laser, plasma 3693
 
  • J. Zhang, Y.X. He, J.F. Hua, D.X. Liu, W. Lu, Y. Ma, C.H. Pai, Y.P. Wu
    TUB, Beijing, People’s Republic of China
  • Z. Nie, Q. Su
    UCLA, Los Angeles, California, USA
 
  Plasma based accelerators (PBAs) have a proven capability to generate high energy electron beams with ultrashort duration (~ 10 fs) and high peak current (~ 10 kA), which opens the opportunity for compact free electron lasers. To meet the requirements of such challenging applications, controllable injection is highly needed to produce high-quality and highly stable electron beams. As we know, the beam parameters,including the current profile, strongly depend on the injection process. To explore the underlying physics and optimize beam parameters in PBAs, a temporal characterization is highly required for different injection schemes. Based on coherent transition radiation(CTR) method, the preliminary experiment to measure beam temporal profiles from both self-injection and ionization injection schemes in a single-shot mode has been performed at Tsinghua University. And the simulations using the similar experimental parameters have been performed to interpret the different injection processes, which show some agreement with the experimental results, especially for the features of bunch durations  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW048  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPGW051 MCP Based Detectors of European XFEL FEL, detector, photon, electron 3703
 
  • E. Syresin, O.I. Brovko, A.Yu. Grebentsov
    JINR, Dubna, Moscow Region, Russia
  • W. Freund, J. Grünert
    EuXFEL, Schenefeld, Germany
  • M.V. Yurkov
    DESY, Hamburg, Germany
 
  Radiation detectors based on microchannel plates (MCP) are used for measurements of the SASE process of the European XFEL. Detectors operate in a wide dynamic range from the level of spontaneous emission to the saturation level (between a few nJ and 25 mJ) and in a wide wavelength range from 0.05 nm to 0.4 nm for SASE1 and SASE2 and from 0.4 nm to 4.43 nm for SASE3. Photon pulse energies are measured by the MCPs with an anode and by a photodiode. The MCP imager measures the photon beam image with a phosphor screen. Three MCP detectors are installed, one behind each SASE undulator (SASE1, SASE2, and SASE3). Calibration and first experiments with the MCP detectors are under discussion.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW051  
About • paper received ※ 29 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPGW058 Design and Study of a 6 Degree-Of-Freedom Universal Adjustment Platform for HL-LHC Components alignment, operation, ECR, target 3720
 
  • M. Sosin, T. Blaszczyk, A. Herty, J. Jaros, H. Mainaud Durand
    CERN, Meyrin, Switzerland
 
  In the accelerator domain, the safe and easy alignment of components located in radioactive areas, is a main concern. The position of devices, such as magnets and collimators, has to be adjusted in a fast and ergonomic way to decrease the ionizing dose received by the personnel. Each equipment type has its own unique set of requirements such as the weight, or the desired position accuracy. The two opposite approaches are, on one hand, a simple and time-consuming manual adjustment, using regulating screws and shims, and, on the other hand, the use of precise and expensive automatic positioning stages and platforms. In the frame of the High Luminosity LHC project, in order to fulfill the safety and technical requirements of alignment for lightweight components, a standardized system is under development. It will provide easy, low-cost and fast adjustment capability for several types of components that could be embarked on it. This paper describes the design, the study and the test results of such a universal adjustment solution. The engineering approach, the lessons learned, the issues and the mechanical components behavior are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW058  
About • paper received ※ 10 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPGW062 The New CERN East Area Primary and Secondary Beams target, secondary-beams, optics, proton 3730
 
  • E. Montbarbon, D. Banerjee, J. Bernhard, D. Brethoux, M. Brugger, B.D. Carlsen, N. Charitonidis, A. Ebn Rahmoun, S. Evrard, L. Gatignon, A. Gerbershagen, E. Harrouch, M. Lazzaroni, B. Rae, M.S. Rosenthal, M.W.U. Van Dijk
    CERN, Geneva, Switzerland
 
  The East Area is one of the intensely used facilities at CERN, now serving for over 56 years beams to more than 20 user teams and experiments for about 200 days of running each year. Besides primary proton and ion beams for the irradiation facilities IRRAD and CHARM, mixed secondary beams of hadrons, electrons and muons within a range of 0.5 GeV/c to 12 GeV/c are provided. The CERN management approved an upgrade and renovation of the full facility to meet reliably future beam test and physics requirements. We present new, flexible beam optics that will assure better purity of the secondary beams, even with the new possibility of highly pure electron, hadron or muon beams. The upgrade also includes a pulsed powering scheme with energy recovering power supplies and new laminated magnets that will reduce both power and cooling requirements. The renovation phase started already and first beams in the new facility will be delivered from 2021 on.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW062  
About • paper received ※ 03 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPGW063 The "Physics Beyond Colliders" Projects for the CERN M2 Beam experiment, optics, hadron, detector 3734
 
  • D. Banerjee, J. Bernhard, M. Brugger, N. Charitonidis, L. Gatignon, A. Gerbershagen, E. Montbarbon, B. Rae, M.S. Rosenthal, M.W.U. Van Dijk, B. Veit, V. de Jesus
    CERN, Geneva, Switzerland
  • S. Cholak
    Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
  • G. D’Alessandro
    JAI, Egham, Surrey, United Kingdom
 
  Physics Beyond Colliders is an exploratory study aimed at exploiting the full scientific potential of CERN’s accelerator complex up to 2040 and its scientific infrastructure through projects complementary to the existing and possible future colliders. Within the Conventional Beam Working Group (CBWG), several pro-jects for the M2 beam line in the CERN North Area were proposed, such as a successor for the COMPASS experiment, a muon programme for NA64 dark sector physics, and the MuonE proposal aiming at investigating the hadronic contribution to the vacuum polarisation. We present integration and beam optics studies for 100-160 GeV/c muon beams as well as an outlook for improvements on hadron beams, which include RF-separated options and low-energy antiproton beams and radiation studies for high intensity beams. In addition, necessary beam instrumentation upgrades for beam particle identification and momentum measurements are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW063  
About • paper received ※ 30 April 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPGW070 Design of the Cockcroft Beamline: Adjustable Transport of Laser Wakefield Electrons to an Undulator undulator, electron, laser, plasma 3749
 
  • K.A. Dewhurst, H.L. Owen
    UMAN, Manchester, United Kingdom
  • E. Brunetti, D.A. Jaroszynski, S.M. Wiggins
    USTRAT/SUPA, Glasgow, United Kingdom
  • B.D. Muratori
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • M.J. de Loos, S.B. van der Geer
    Pulsar Physics, Eindhoven, The Netherlands
 
  Funding: Work supported by U.K. STFC (Grant No. ST/G008248/1), EuPRAXIA (Grant No. 653782), ECs LASERLAB-EUROPE (Grant No. 654148), U.K. EPSRC (Grant No. EP/J018171/1, EP/J500094/1 and EP/N028694/1).
The Cockcroft Beamline is being designed to transport 1 GeV electrons from a laser wakefield accelerator (LWFA) to an undulator at the Scottish Centre for the Application of Plasma-based Accelerators (SCAPA) in Glasgow, UK. To demonstrate undulator radiation in the X-ray spectral region and potentially free electron laser (FEL) gain, electrons should be transported between the LWFA and the undulators with high fidelity. In this paper we present the design of an adjustable beam line to transport LWFA electrons to the undulator for a range of energies, from 0.5 GeV to 1 GeV, while preserving the electron beam properties and matching the undulator-beam coupling.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW070  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPGW071 Genetic Optimisation of Beamline Design for DIAMOND synchrotron, framework, photon, experiment 3753
 
  • F. Bakkali Taheri, M. Apollonio, R. Bartolini, B. Singh
    DLS, Oxfordshire, United Kingdom
  • R. Bartolini, J. Li
    JAI, Oxford, United Kingdom
  • R. Bartolini
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
 
  The problem of optimisation of beamline structures is studied, from the point of view of multi-objective genetic algorithms. While this approach has been successfully used in the exploration of potential particle accelerator lattices, it has never been applied to beamline design. In this paper, the Non-Dominated Sorting Genetic Algorithm II (NGSA II) is used to optimize a structure where photons are assumed to propagate through the optical elements according to the wavefront model as implemented in SRW. It is shown that appropriate objective functions can help to set up an interesting set of parameters, with competitive computational resources compared to the traditional approach. Examples illustrating this optimization method are shown in the context of DIAMOND.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW071  
About • paper received ※ 13 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPRB030 Novel FPGA-based Instrumentation for Personnel Safety Systems in Particle Accelerator Facility FPGA, controls, monitoring, operation 3872
 
  • S. Pioli, M. Belli, M.M. Beretta, B. Buonomo, P. Ciambrone, D.G.C. Di Giulio, O. Frasciello, A. Variola
    INFN/LNF, Frascati, Italy
  • P. Valente
    INFN-Roma, Roma, Italy
 
  Personnel safety system for particle accelerator facility involves different devices to monitor gates, shielding doors, dosimetry stations, search and emergency buttons. In order to achieve the proper reliability, fail-safe and fail-proof capabilities, these systems are developed compliant with safety standards (like the IEC-61508 on ’Functional Safety’, ANSI N43.1 ’Radiation Safety for the design and operation of Particle Accelerator’ and NCRP report 88) involving stable technologies like electro-mechnaical relays and, recently, PLC. As part of the Singularity project at Frascati National Laboratories of INFN, this work will report benchmark of a new FPGA-based system from the design to the validation phase of the prototype currently operating as personnel safety system at the Beam Test Facility (BTF) of Dafne facility. This novel instrument is capable of: devices monitoring in real-time at 1 kHz, dual modular redundancy, fail-safe and fail-proof, multi-node distributed solution on optical link, radiation damage resistance and compliant with IEC-61508, ANSI N43.1 and NCRP report 88. The aim of this FPGA-based system is to illustrate the feasibility of FPGA technology in the field of personnel safety for particle accelerator in order to take advantage of a fully digital system integrated with facility control system, evaluate the related reliability and availability and realize a standard, scalable and flexible hardware solution also for other fields with similar requirements like machine protection systems.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB030  
About • paper received ※ 30 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPRB053 Upgrade of the Historical Data Query and Analysis System for HLS-II database, status, real-time, operation 3928
 
  • Z.Y. Xie, C. Li, G. Liu, Z.X. Shao, Y. Song, J.G. Wang, K. Xuan
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  The current historical data query and analysis system for the Hefei Light Source II (HLS-II) was developed with Apache Struts2. However, Apache Struts2 need to be fixed from time to time to avoid being attacked. Therefore, a new system based on Spring Boot and Vue.js is developed. Meanwhile, the performance of the system is optimized, and the radiation monitor module is added. This paper will detail the system architecture and software implementation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB053  
About • paper received ※ 24 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPRB059 Radiation Safety at SOLARIS 1.5 GeV Storage Ring storage-ring, injection, electron, MMI 3940
 
  • M.B. Jaglarz
    SOLARIS, Kraków, Poland
  • A.I. Wawrzyniak, J. Wikłacz
    Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
 
  Radiation measurements at Solaris are continuously performed by using 9 radiation monitor stations (RMS) located around the storage ring and the beamlines area. 4 of RMS are connected to the Personal Safety System and in case of exceeding alarm level dump the beam or close safety shutters. Moreover thermoluminescence dosimeters (TLDs) are used to registered doses in the classified areas according to the Polish regulation. Measurements are performed since 2015 when the commissioning of the storage ring has started. Since that time several improvements to the radiation shielding was done to fulfill the ALARA principle. Moreover the electron beam optimizations during the injection, ramping and operation were performed to decrease the electrons losses and the radiation level. This presentation will report on radiation measurements results obtained before and after the chopper installation. Additionally problems with radiation level while the beam current is increasing to the designed 500mA value will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB059  
About • paper received ※ 26 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPRB083 Detailed Analysis Of The Baseline Dose Levels And Localized Radiation Spikes In The Arc Sections Of The Large Hadron Collider During Run 2 operation, experiment, ECR, monitoring 4009
 
  • K. Bilko, M. Brugger, R. Garcia Alia, F.J. Harden, Y. Kadi, O. Stein
    CERN, Geneva, Switzerland
 
  The Large Hadron Collider (LHC) has eight insertion regions (IRs) which house the large experiments or accelerator equipment. These IRs are interconnected with the arc sections consisting of a periodic magnet structure. During the operation of the LHC small amounts of the beam particles are lost, creating prompt radiation fields in the accelerator tunnels and the adjacent caverns. One of the main loss mechanisms in the LHC arc sections is the interaction of the beam particles with the residual gas molecules. The analysis of the dose levels based on the beam loss measurement data shows that the majority of the measurements have similar levels, which allow to define baseline values for each arc section. The baseline levels decreased during the years 2015, 2016 and stabilised in 2017 and 2018 at annual dose levels below 50 mGy, which can be correlated with the residual gas densities in the LHC arcs. In some location of the arcs radiation spikes exceed the base line by more than two orders of magnitude. In addition to the analysis of these dose levels, a novel approach of identifying local dose maxima and the main driving mechanisms creating these radiation spikes will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB083  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPRB084 Run 2 Prompt Dose Distribution and Evolution at the Large Hadron Collider and Implications for Future Accelerator Operation operation, collimation, proton, luminosity 4013
 
  • O. Stein, K. Bilko, M. Brugger, R. Garcia Alia, F.J. Harden, Y. Kadi, A. Lechner, G. Lerner
    CERN, Geneva, Switzerland
 
  During the operation of the Large Hadron Collider (LHC) small fractions of beam particles are lost, creating prompt radiation fields in the accelerator tunnels. Exposed electronics and accelerator components show lifetime degradation and stochastic Single Event Effects (SEEs) which can lead to faults and downtime of the LHC. Close to the experiments the radiation levels scale nicely with the integrated luminosity since the luminosity debris is the major contributor for creating the radiation fields in this area of the LHC. In the collimation regions it was expected that the radiation fields scale with the integrated beam intensities since the beams are continuously cleaned from particles which exceed the accelerator’s acceptance. The analysis of radiation data shows that the dose measurements in the collimation regions normalised with the integrated beam intensities for 2016 and 2017 are comparable. Against expectations, the intensity normalised radiation datasets of 2018 in these regions differ significantly from the previous years. Especially in the betatron collimation region the radiation levels are up to a factor 3 higher. The radiation levels in the collimation regions correlate with the levelling of beta-star and the crossing angle in the high luminosity experiments ATLAS and CMS. These increased normalised doses have direct implications on the expected dose levels during future LHC operation, including the High-Luminosity LHC (HL-LHC) upgrade.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB084  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPRB085 HiRadMat: A Facility Beyond the Realms of Materials Testing proton, experiment, target, instrumentation 4016
 
  • F.J. Harden, A. Bouvard, N. Charitonidis, Y. Kadi
    CERN, Geneva, Switzerland
 
  The ever-expanding requirements of high-power targets and accelerator equipment has highlighted the need for facilities capable of accommodating experiments with a diverse range of objectives. HiRadMat, a High Radiation to Materials testing facility at CERN has, throughout operation, established itself as a global user facility capable of going beyond its initial design goals. Pulsed high energy, high intensity, proton beams have been delivered to experiments ranging from materials testing, detector’s prototype validation, radiation to electronics assessment and beam instrumentation. A 440 GeV/c proton beam is provided directly from the CERN SPS. Up to 288 bunches/pulse at a maximum pulse intensity of 3.5 x 1013 protons/pulse can be delivered. Through collaborative efforts, HiRadMat has developed into a state-of-the-art facility with improved in situ measurement routines, beam diagnostic systems and data acquisition techniques, offered to all users. This contribution summarises the recent experimental achievements, highlights previous facility enhancements and discusses potential future upgrades with particular focus on HiRadMat as a facility open to novel experiments.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB085  
About • paper received ※ 29 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPRB086 Design & Optimization of the Alignment Supports for the New Laminated Magnets for the CERN East Area Consolidation Project alignment, operation, GUI, secondary-beams 4020
 
  • R. Vanhoutte, D. Brethoux, A. Ebn Rahmoun, S. Evrard, F.J. Harden, E. Harrouch, M. Lazzaroni, M. Lino Diogo dos Santos, R. Lopez, D.E. Nogtikov, J. Renedo Anglada
    CERN, Meyrin, Switzerland
 
  The East Area is one of CERNs experimental area, running since its foundation in 1958. Extracting a 24GeV proton beam from the Proton Synchrotron accelerator, the primary beam is divided into different secondary beams, serving various experiments and user’s facilities such as CLOUD, CHARM, IRRAD. Due to improved optics and an energy saving scheme, the facility will go under a renovation between 2019 and 2020, including the replacement of the magnets with new laminated ones to allow a cycled powering scheme. Those magnets need improved supports, and in some cases even a new design, to optimize the alignment operations in those areas. This article will mainly address the different proposed solutions for plug-in supports as well as for conventional ones.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB086  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPRB087 Study of the Energy Savings Resulting from the East Area Renovation ECR, experiment, operation, power-supply 4023
 
  • B. LM. Lamaille, F. Dragoni, S. Evrard, F.J. Harden, E. Harrouch, M. Lazzaroni, R. Lopez, K.D. Papastergiou
    CERN, Meyrin, Switzerland
 
  CERN’s East Experimental Area, situated on the Swiss side of the Meyrin site, with its four beamlines, has served physics for more than 40 years. As the building and equipment are reaching their end of life, a thorough consolidation project has been initiated in order to pro-vide many more years of reliable operation. This article addresses the different proposed solutions to reduce significantly the energy consumption of the East Area. It outlines the methodology applied to estimate as precisely as possible the future attained energy savings, which will result in an estimated reduction of approximately 80% in electricity usage (from 11 GWh to 2 GWh per year) and of approximately 65% in gas usage for heating purpose (from 3 GWh to 1 GWh per year).  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB087  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPRB088 Optimizing The Reliability of The Fire Alarm System in The Taiwan Photon Source detector, controls, shielding, storage-ring 4026
 
  • W.S. Chan, F.-D. Chang, C.S. Chen, Y.F. Chiu, J.C. Liu, Z.-D. Tsai
    NSRRC, Hsinchu, Taiwan
 
  The fire alarm system plays a critical role for the safety of building occupants. However, in the past two years from 2016 to 2017, occasionally false alarms at the Taiwan Photon Source (TPS) occurred. Results of more detailed observations indicated that radiation and/or electromagnetic interference (EMI) of the TPS accelerator disturb smoke detectors and signal line circuits (SLCs). Lead shielding covers, adjusting of the detector alarm verification time and a laser-based aspi-rating smoke detector were used to reduce the probabil-ity that fire alarms become activated to less than 0.5 times per year.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB088  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPRB098 FETS Personnel & Machine Interlock Systems controls, timing, ion-source, status 4057
 
  • J.H. Macgregor
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
 
  The Front End Test Stand (FETS) [1] is a high energy pulsed proton driver that aims to produce a perfectly chopped 50 Hz, 60 mA, 2 ms H’ beam. FETS consists of a Penning Ion source, Low Energy Beam Transport (LEBT), 4 m long bolted construction 324 MHz four vane Radio Frequency Quadrupole (RFQ). The H’ Beam will be perfectly chopped so that bunches of particles can be trapped and accelerated with very low loss into a circular accelerator. To protect personnel from X-ray radiation along with prompt neutrons & gamma radiation, a concrete block-house has been built around the facility and a personnel interlock and search system developed. This paper discusses the mechanical and electrical systems used to ensure personnel safety via the Personnel Protection System (PPS) and machine safety by use of a Programmable Logic Controller, (PLC), used as the Machine Interlock Systems.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB098  
About • paper received ※ 09 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPRB118 Study on the Influence of the Range Shifter Material in a Scanning Nozzle for Proton Therapy Based on Monte Carlo Method proton, neutron, ECR, scattering 4100
 
  • Y.C. Yu, H.D. Guo, Y.Y. Hu, X.Y. Li, Y.J. Lin, P. Tan, X.D. Tu, L.G. Zhang
    HUST, Wuhan, People’s Republic of China
 
  Range shifter plays a key role in decreasing the energy of the proton beam to realize shallow tumours treatment with the scanning nozzle in Huazhong University of Science and Technology Proton Therapy Facility (HUST-PTF). To control the transverse scattering and decrease the damage to healthy tissue caused by secondary particle, influence of the range shifter material was studied. In this paper, the Monte Carlo software Geant4 and FLUKA are applied to analyse the transport process of proton beam in the range shifters made of six different materials: PMMA, Lexan, Lucite, Polyethylene, Polystyrene, and Wax. The beam spot sizes at the iso-center with or without range shifter was calculated for the HUST-PTF scanning nozzle. The relationship between the thickness of the range shifters of the six materials and the proton energy was obtained. The secondary neutron yield at the end of the nozzle was also analysed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB118  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPTS036 Quench Detection and Diagnostic Systems for the Superconducting Circuits for the HL-LHC dipole, luminosity, data-acquisition, electronics 4183
 
  • R. Denz, D.O. Calcoen, E. De Matteis, V. Froidbise, S. Georgakakis, S. Haas, S. Mundra, T. Podzorny, A.P. Siemko, J. Spasic, J. Steckert
    CERN, Geneva, Switzerland
  • D. Blasco Serrano
    CIEMAT, Madrid, Spain
 
  The High Luminosity LHC project (HL-LHC) will incorporate a new generation of superconducting elements such as high field superconducting magnets based on Nb3Sn conductors and MgB2 based high temperature superconducting links for magnet powering. In addition, the HL-LHC will also feature new generations of NbTi based magnets. The proper protection and diagnostics of those elements require the development of a new generation of integrated quench detection and data acquisition systems as well as novel methods for quench detection. The next generation of quench detection systems is to a large extent software defined and serves at the same time as high performance data acquisition system. The contribution will discuss the specific needs of HL-LHC in terms of quench detection and present recent results from tests with prototype magnets. The contribution will show the implementation of new quench detection methods such as current derivative sensors. Measures for increasing the system dependability and easing its maintenance will be explained, as well as the improved supervision architecture using Ethernet based field-bus systems for fast data transmission.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS036  
About • paper received ※ 07 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPTS046 The Limited B-Field Integral of Superconducting Longitudinal Gradient Bend Magnet simulation, emittance, storage-ring, synchrotron-radiation 4213
 
  • C. Chen, L. Wang, H.R. Zhang, T. Zhang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  The National Synchrotron Radiation Laboratory (NSRL) is planning a fourth generation diffraction-limited light source–Hefei Advanced Light Source (HALS), it is based on a seven-bend achromat lattice providing an ultralow natural emittance of 34 pm rad. The emittance can be even lower with the use of longitudinal gradient bends (LGBs) and anti-bends (ABs). The designed energy for HALS is 2.4 GeV, superconducting LGB might be employed instead of normal bending magnet since it can improve radiated beam critical energy to hard x-ray regions without using up any straight sections. To get a peak field about 6 T and small B-field profile full width half maximum, SLS-2 type LGB is considered. In this paper, the limited B-field integral (along the beam path) is trying to be find with some restrictions.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS046  
About • paper received ※ 12 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPTS067 Characterisation of the Radiation Hardness of Cryogenic Bypass Diodes for the HL-LHC Inner Triplet Quadrupole Circuit neutron, experiment, quadrupole, luminosity 4268
 
  • D. Wollmann, C. Cangialosi, C. Cangialosi, F. Cerutti, G. D’Angelo, S. Danzeca, R. Denz, M. Favre, R. Garcia Alia, D. Hagedorn, A. Infantino, G. Kirby, L. Kistrup, T. Koettig, J. Lendaro, B. Lindstrom, A. Monteuuis, F. Rodriguez-Mateos, A.P. Siemko, K. Stachon, A. Tsinganis, M. Valette, A.P. Verweij, A. Will
    CERN, Meyrin, Switzerland
  • A. Bernhard, A.-S. Müller
    KIT, Karlsruhe, Germany
 
  Funding: Work supported by the HL-LHC Project.
The powering layout of the new HL-LHC Nb3Sn triplet circuits is the use of cryogenic bypass diodes, where the diodes are located inside an extension to the magnet cryostat, operated in superfluid helium and exposed to radiation. Therefore, the radiation hardness of different type of bypass diodes has been tested at low temperatures in CERN’s CHARM irradiation facility during the operational year 2018. The forward characteristics, the turn on voltage and the reverse blocking voltage of each diode were measured weekly at 4.2 K and 77 K, respectively, as a function of the accumulated radiation dose. The diodes were submitted to a dose close to 12 kGy and a 1 MeV equivalent neutron fluence of 2.2x1014,n/cm2. After the end of the irradiation campaign the annealing behaviour of the diodes was tested by increasing the temperature slowly to 300 K. This paper describes the experimental setup, the measurement procedure and discusses the results of the measurements.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS067  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPTS073 Radiation Damage to Undulator Electronics at an Electron Accelerator electron, electronics, photon, neutron 4285
 
  • T.Y. Chung, C.-H. Chang, A.Y. Chen, Y.W. Chen, J.C. Huang, J.C. Jan
    NSRRC, Hsinchu, Taiwan
 
  Experience gained from commissioning and operation of three elliptical polarization undulators (EPU) at the TPS taught us that undulator driving systems can behave erratically following a beam dump or loss. In this work, we discuss possible harmful radiation sources in a storage ring and analyse the effect of lack of electronic component radiation resistance in the system. According to measurements of spatial radiation distribution at the TPS, we propose solutions and an improved design for Phase-II EPUs.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS073  
About • paper received ※ 19 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPTS077 Beam Instability Induced by RF System of an FEL-THZ Source electron, FEL, linac, target 4298
 
  • X.D. Tu, G. Feng, S.J. He, T. Hu, J. Jiang, S.Y. Lu, Y.Q. Xiong
    HUST, Wuhan, People’s Republic of China
 
  An SLAC-like Compact Linac installed on the HUST FEL-THz has been used as an injector to produce high power THz radiation. To meet the requirements of monochromaticity and repeatability for FEL, performance of electron beam and stability of RF system are notable. According to the existing facility, based on measurement results of RF jitter, instability of beam has been calculated, and it has been verified in relevant experiments. Furthermore, stability targets in RF system has been pro-posed in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS077  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPTS093 Synchrotron Radiation Heating of the Helical Superconducting Undulator photon, vacuum, synchrotron, synchrotron-radiation 4328
 
  • J.C. Dooling, R.J. Dejus, V. Sajaev
    ANL, Argonne, Illinois, USA
 
  Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02- 06CH11357.
A helical superconducting undulator (HSCU) was installed in the Advanced Photon Source (APS) Storage Ring (SR) during the January 2018 maintenance period. Shortly after the reintroduction of beam into the SR in late January, higher than expected heating was observed in the cryogenic cooling system. Steering the electron beam orbit in the upstream dipole provided reduction of the amount of synchrotron radiation reaching into the HSCU and allowed the device to properly cool and operate. Modeling the HSCU geometry with MARS shows the importance of Compton Scattering in transferring synchrotron photons with energies in the range of 10-100 keV through the vacuum chamber into the HSCU magnet pole and winding regions. Simulations carried out using MARS with EGS5 enabled indicate a rapid increase in transfer efficiency from the chamber wall to the HSCU with photon energy. Realistic spectral distributions of synchrotron photons are employed as input to MARS for several bending magnet field strengths.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS093  
About • paper received ※ 12 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
FRXXPLS3 Application of a Phase Space Beam Position and Size Monitor for Synchrotron Radiation electron, synchrotron, detector, synchrotron-radiation 4376
 
  • N. Samadi
    University of Saskatchewan, Saskatoon, Canada
  • L.D. Chapman, L.O. Dallin
    CLS, Saskatoon, Saskatchewan, Canada
  • X. Shi
    ANL, Argonne, Illinois, USA
 
  We will report on a system (ps-BPM) that can measure the electron source vertical position and angular motion along with the vertical source size and angular size at a single location in a synchrotron bend magnet beamline*. This system uses a combination of a monochromator and a filter with a K-edge to which the monochromator was tuned in energy. The vertical distribution of the beam with and without the filter was simultaneously visualized with an imaging detector. The small range of angles from the source onto the monochromator crystals creates an energy range that allows part of the beam to be below the K-edge and the other part above. Measurement of the beam vertical location without the absorber and edge vertical location with the absorber allowes measurement of the source position and angle. The beam width and edge width give information about the vertical electron source size and angular distribution. The ps-BPM measurements have been made where the electron beam size and angular distribution was adjusted using skew quads. The ps-BPM measurements correlate well with modeling of the ps-BPM system as well as conventional beam size measurements using a pinhole.
* A phase-space beam position monitor for synchrotron radiation. J Synchrotron Radiat, 2015. 22(4): p. 946-55.
 
slides icon Slides FRXXPLS3 [4.593 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-FRXXPLS3  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)