MOPRB —  Poster Session - Redback Spider   (20-May-19   16:00—18:00)
Paper Title Page
MOPRB001 Low Emittance Tuning of FCC-ee 574
 
  • T.K. Charles
    The University of Melbourne, Melbourne, Victoria, Australia
  • S. Aumon, B.J. Holzer, F. Zimmermann
    CERN, Geneva, Switzerland
  • K. Oide
    KEK, Ibaraki, Japan
 
  The FCC-ee project studies the design of a future 100 km e+/e circular collider for precision studies and rare decay observations in the range of 90 to 350 GeV center of mass energy with luminosities in the order of 1036 cm-2s-1. In order to reach these luminosity requirements, extreme focusing is needed in the interaction regions. For the Z energy (45.6 GeV) lattice, the maximum beta value is 8322 m, and the vertical beta function is 0.8 mm at the IP. These aspects of the FCC-ee lattice make it particularly susceptible to misalignments and field errors, and therefore present an appreciable challenge for emittance tuning. A challenging correction scheme is proposed to reduce the coupling and the vertical emittance. We describe a comprehensive correction strategy used for the low emittance tuning. The strategy includes special programs, that had been developed to optimise the lattice based on Dispersion Free Steering, linear coupling compensation based on Resonant Driving Terms and beta beat correction utilising response matrices. Thousands of misalignment and field error random seeds were introduced in MADX simulations and the final corrected lattices are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB001  
About • paper received ※ 09 April 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
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MOPRB003 Multi-Target Lattice for Muon Production From e+ Beam Annihilation on Target 578
 
  • O.R. Blanco-García
    LAL, Orsay, France
  • M. Antonelli, M.E. Biaginipresenter, M. Boscolo, A. Ciarma, S. Guiducci, C. Vaccarezza, A. Variola
    INFN/LNF, Frascati, Italy
  • G. Cesarini
    INFN-Roma, Roma, Italy
  • F. Collamati
    INFN-Roma1, Rome, Italy
  • R. Li Voti
    Sapienza University of Rome, Rome, Italy
  • P. Raimondi
    ESRF, Grenoble, France
 
  The Low Emittance Muon Accelerator~(LEMMA) aims at producing small emittance muons from positron annihilation with electrons in a target. Given the low cross section of the production process, a large number of positrons on the target are required, exposing it to high power deposition and the beam to large degradation because of multiple scattering and bremstrahlung. A multi-target IP, and multi-IP line has been studied to reduce the power deposition per target and the degradation of the positron beam while preserving the number of muon pairs produced. The lattice copes with the focusing and transport of three beams at two different energies, the positron beam at 45 GeV, and µ++ and µ beams at 22.5~GeV. Studies on the beam dynamics, number of targets, material and thickness of the targets are reported in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB003  
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB004 The European Spallation Source Neutrino Super Beam Design Study 582
 
  • M. Dracos, E. Bouquerel
    IPHC, Strasbourg Cedex 2, France
  • G. Fanourakis
    Institute of Nuclear and Particle Physics, Attiki, Greece
  • G. Gokbulut, A. Kayis Topaksu
    Cukurova University, Adana, Turkey
 
  Funding: This project is supported by the COST Action CA15139 EuroNuNet. It has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 777419.
The discovery of oscillations and the latest progress in neutrino physics will make possible to observe for the first time a possible CP violation at the level of leptons. This will help to understand the disappearance of antimatter in the Universe. The ESSnuSB* project proposes to use the proton linac of the ESS currently under construction to produce a very intense neutrino Super Beam, in parallel with the spallation neutron production. The ESS linac is expected to deliver 5 MW average power, 2 GeV proton beam, with a rate of 14 Hz and pulse duration of 2.86 ms. By doubling the pulse rate, 5 MW power more can be provided for the production of the neutrino beam. In order to shorten the proton pulse duration to few μs requested by the neutrino facility, an accumulation ring is needed, imposing the use and acceleration of H instead of protons in the linac. The neutrino facility also needs a separate target station with a different design than the one of the neutron facility. On top of the target, a hadron magnetic collecting device is needed in order to focus the emerging hadrons from the target and obtain an intense neutrino beam directed towards the neutrino detector.
A Very Intense Neutrino Super Beam Experiment for Leptonic CP Violation Discovery based on the European Spallation Source Linac, Nuclear Physics B, Vol 885, Aug 2014, 127-149, arXiv:1309.7022.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB004  
About • paper received ※ 10 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB005 Study of Higher-Order Achromat Lattice as an Alternative Option for the SOLEIL Storage Ring Upgrade 586
 
  • R. Nagaoka, A. Bence, P. Brunelle, L. Hoummi, A. Loulergue, A. Nadji, L.S. Nadolski, M.-A. Tordeux, A. Vivoli
    SOLEIL, Gif-sur-Yvette, France
  • A. Gamelin
    LAL, Orsay, France
 
  A ring composed of 20 symmetrical 7BA cells in which of a pair of chromaticity correcting sextupoles placed around horizontal dispersion bumps à la ESRF-EBS was developed as a baseline lattice for the SOLEIL storage ring upgrade (presented at IPAC2018). The strict phase relation between the two dispersion bumps provides an efficient way of optimizing the (on-momentum) nonlinear optics with a limited number of sextupoles. As an alternative, a scheme known as Higher-Order Achromat (HOA) develops a MBA (Multi-Bend Achromat) lattice where chromaticity correcting sextupoles are distributed in each M unit cell with a strict phase relation cell-wise such as to cancel basic geometric and chromatic resonance driving terms. The beam dynamics in a 20-fold 7BA HOA ring is compared with those of the baseline lattice, with focus on off-momentum properties such as Touschek lifetime, which are important for medium energy rings like SOLEIL. The robustness against errors, the reduction of the ring symmetry by introducing 4 longer straight sections, as well as a horizontal dispersion bump to cope with longitudinal on-axis injection scheme are also presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB005  
About • paper received ※ 22 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB006 HOM Damping Options for the Z-Pole Operating Scenario of FCC-ee 590
SUSPFO013   use link to see paper's listing under its alternate paper code  
 
  • S. Gorgi Zadeh
    Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
  • R. Calaga
    CERN, Meyrin, Switzerland
  • T. Flisgen
    FBH, Berlin, Germany
  • U. van Rienen
    University of Rostock, Rostock, Germany
 
  The Z-pole option of FCC-ee is an Ampere class machine with a beam current of 1.39 A. Due to high HOM power and strong HOM damping requirements, the present baseline of FCC-ee considers a single cell cavity at 400 MHz. In this paper, different HOM damping schemes are compared for the Z-pole operating scenario with the aim of lowering the parasitic longitudinal and transverse impedance. The HOM power for each damping scheme is also calculated.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB006  
About • paper received ※ 15 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB011 Progress on Muon Ionization Cooling Demonstration with MICE 594
 
  • C. Hunt
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • V.C. Palladino
    INFN-Napoli, Napoli, Italy
  • C.G. Whyte
    USTRAT/SUPA, Glasgow, United Kingdom
 
  Funding: STFC, NSF, DOE, INFN, CHIPP andd more
The Muon Ionization Cooling Experiment (MICE) at RAL has collected extensive data to study the ionization cooling of muons. Several million individual particle tracks have been recorded passing through a series of focusing magnets in a number of different configurations and a liquid hydrogen or lithium hydride absorber. Measurement of the tracks upstream and downstream of the absorber has shown the expected effects of the 4D emittance reduction. Further studies are providing now more and deeper insight.
Submitted by the chair of our MICE speakers bureau.
If accepted, a member of the collaboration will soon be identified to present the contribution and will register immediately after.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB011  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB012 RECENT RESULTS FROM MICE ON MULTIPLE COULOMB SCATTERING AND ENERGY LOSS 598
 
  • C.G. Whyte
    USTRAT/SUPA, Glasgow, United Kingdom
  • J.C. Nugent
    University of Glasgow, Glasgow, United Kingdom
 
  Funding: STFC, NSF, DOE, INFN, CHIPP and more
Multiple Coulomb scattering and energy loss are well known phenomena experienced by charged particles as they traverse a material. However, from recent measurements by the MuScat collaboration, it is known that the simulation code (GEANT4) available at the time overestimated the scattering of muons in low Z materials. Updates to GEANT4 have brought the simulations in line with the MuScat data and these new models can be validated over a larger range of momentum, 170-250 MeV/c, with MICE data. This is of particular interest to the Muon Ionization Cooling Experiment (MICE) collaboration which has the goal of measuring the reduction of the emittance of a muon beam induced by energy loss in low Z absorbers. MICE took data without magnetic field suitable for multiple scattering measurements in the spring of 2016 using a lithium hydride absorber and in the fall of 2017 using a liquid hydrogen absorber. The measurement in lithium hydride is reported here along with the preliminary measurements in liquid hydrogen. In the fall of 2016 MICE took data with magnetic fields on and measured the energy loss of muons in a lithium hydride absorber. These data are all compared with the Bethe-Bloch formula and with the predictions of various models, including the default GEANT4 model.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB012  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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MOPRB013 Focusing of High-Brightness Electron Beams with Active-Plasma Lenses 601
 
  • R. Pompili
    INFN/LNF, Frascati, Italy
 
  Plasma-based technology promises a tremendous reduction in size of accelerators used for research, medical, and industrial applications, making it possible to develop tabletop machines accessible for a broader scientific community. By overcoming current limits of conventional accelerators and pushing particles to larger and larger energies, the availability of strong and tunable focusing optics is mandatory also because plasma-accelerated beams usually have large angular divergences. In this regard, active-plasma lenses represent a compact and affordable tool to generate radially symmetric magnetic fields several orders of magnitude larger than conventional quadrupoles and solenoids. However, it has been recently proved that the focusing can be highly nonlinear and induce a dramatic emittance growth. Here, we present experimental results showing how these nonlinearities can be minimized and lensing improved. These achievements represent a major breakthrough toward the miniaturization of next-generation focusing devices.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB013  
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB017 Development of Inter-Digital H-Mode Drift-Tube Linac Prototype with Alternative Phase Focusing for a Muon Linac in the J-PARC Muon G-2/EDM Experiment 606
SUSPFO041   use link to see paper's listing under its alternate paper code  
 
  • Y. Nakazawa, H. Iinuma
    Ibaraki University, Ibaraki, Japan
  • K. Hasegawa, Y. Kondo, T. Morishita
    JAEA/J-PARC, Tokai-mura, Japan
  • N. Hayashizaki
    RLNR, Tokyo, Japan
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • Y. Iwata
    NIRS, Chiba-shi, Japan
  • N. Kawamura, T. Mibe, M. Otani, T. Yamazaki, M. Yoshida
    KEK, Ibaraki, Japan
  • R. Kitamura, H.Y. Yasuda
    University of Tokyo, Tokyo, Japan
  • N. Saito
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • Y. Sue
    Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
 
  Funding: This work is supported by JSPS KAKENHI Grant Numbers JP15H03666, JP18H03707, JP16H03987, and JP16J07784.
An inter-digital H-mode drift-tube linac (IH-DTL) is developed in a muon linac at the J-PARC E34 experiment. IH-DTL will accelerate muons from 0.34 MeV to 4.5 MeV at a drive frequency of 324 MHz. Since IH-DTL adopts an APF method, with which the beam is focused in the transverse direction using the RF field only, the proper beam matching of the phase-space distribution is required before the injection into the IH-DTL. Thus, an IH-DTL prototype was fabricated to evaluate the performance of the cavity and beam transmission. As a preparation of the high-power test, a test coupler is designed and fabricated. In this paper, the development of the coupler and the result of the low-power measurement will be presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB017  
About • paper received ※ 29 April 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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MOPRB018 Conceptual Design of Negative-Muon Decelerator for Material Science 610
 
  • C. Ohmori, M. Otani, K. Shimomura
    KEK, Tokai, Ibaraki, Japan
  • T. Takayanagi
    JAEA/J-PARC, Tokai-mura, Japan
 
  In 2018, a Negative-Muon Spin Rotation and Relaxation technique was developed in J-PARC Material and Life Science Facility. It is a novel scheme to investigate the motion of hydrogens in the chemicals and materials. To study small samples, the surface of materials and thin foils, a low energy negative muon beam is required. To decelerate intense 300-keV muons to 15-keV, we propose a system which consists of pulse generators and multi-gap induction decelerators. In this design, an inductive adder scheme is considered to use for the high voltage pulse source. High impedance magnetic alloy ring cores will be loaded in the decelerator cells. The high impedance cores which have much larger size than those for public use were developed for J-PARC RF systems and used for many applications including CERN booster RF, anti-proton deceleration and medical accelerator. In this paper, we present a conceptual design of muon deceleration system.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB018  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB019 Beam Optics Study on FFA-MERIT Ring 613
 
  • H. Okita, Y. Ishi, Y. Kuriyama, Y. Mori, Y. Ono, A. Taniguchi, T. Uesugipresenter
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • N. Ikeda, Y. Yonemura
    Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka, Japan
  • M. Kinsho, K. Okabe, M. Yoshimoto
    JAEA/J-PARC, Tokai-mura, Japan
  • Y. Miyake
    KEK, Tokai, Ibaraki, Japan
  • M. Muto
    New Affiliation Request Pending, -TBS-, Unknown
  • A. Sato
    Osaka University, Osaka, Japan
 
  Funding: This work was funded by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan).
Intense negative muon source MERIT (Multiplex Energy Recovery Internal Target) for the nuclear transformation to mitigate the long lived fission products from nuclear plants has been proposed. For the purpose of proof-of-principle of MERIT scheme, FFA ring has been developed. The results of beam optics study for MERIT ring will be reported in this conference.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB019  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB021 Remodeling of 150 MeV FFAG Main Ring at KURNS to Pion Production Ring 616
 
  • K. Suga, Y. Fuwa, Y. Ishi, Y. Kuriyama, Y. Mori, H. Okita, T. Uesugipresenter
    Kyoto University, Research Reactor Institute, Osaka, Japan
 
  A possibility of remodeling main ring of 150 MeV FFAG accelerator at Kyoto University, Institute for Integrated Radiation and Nuclear Science (KURNS) to Pion Production Ring (PPR) for muon transmutation study has been discussed. Design was made on the assumption that 400 MeV proton beams circulate and hit a target in the ring to generate pions. Optimizations of lattice parameters and 3D magnet modeling are reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB021  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB022 Current Status of the High-Power RF Systems During Phase2 Operation in SuperKEKB 619
 
  • K. Watanabe, K. Marutsuka, Ma. Yoshida, S.I. Yoshimoto
    KEK, Ibaraki, Japan
 
  The SuperKEKB is an asymmetric-energy two-ring collider consisting of the high-energy ring (HER) for 7 GeV electrons and the low-energy ring (LER) for 4 GeV positrons at KEK. Both the electron and positron beams are injected from the Linac injector complex, which includes a newly constructed 1.1 GeV positron damping ring (DR) to supply a high-quality low emittance positron beam to the LER. The high power RF system has a role to drive the ARES cavities and the superconducting RF cavities for the SuperKEKB. The operating frequency of RF system is 508.9 MHz. The required RF power from the klystron at maximum storage beam current is ~850 kW (CW). The number of RF stations is total 31 for the main ring (MR) and DR. The status of each high power RF components, troubles of them and operation condition that occurred during phase 2 commissioning from Feb 2018 to July 2018 will be reported in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB022  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB023 Design of the Wien-Filter Type Spin Rotator for the Low-Emittance Muon Beam 622
SUSPFO050   use link to see paper's listing under its alternate paper code  
 
  • H.Y. Yasuda
    University of Tokyo, Tokyo, Japan
  • H. Iinuma, Y. Nakazawa
    Ibaraki University, Hitachi, Ibaraki, Japan
  • N. Kawamura, T. Mibe, M. Otani
    KEK, Ibaraki, Japan
  • Y. Kondo
    JAEA/J-PARC, Tokai-mura, Japan
  • N. Saito
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  • Y. Sue
    Nagoya University, Graduate School of Science, Chikusa-ku, Nagoya, Japan
 
  Funding: This work was supported by JSPS KAKENHI Grant Numbers JP18J22129, JP18H03707.
Muon linac is developed for the muon g-2/EDM experiment at J-PARC. In this experiment, ultra slow muon is accelerated to a momentum of 300 MeV/c with the four linac structures. This scheme offers new opportunity for precise measurements; it enables us to reverse muon polarization at early stage of acceleration. The reversal of polarization is a common method of precision polarization measurements as it can be used to identify or reduce systematic uncertainties dependent on time. It is necessary to accelerate muons and flip its spin without substantial emittance growth for the experimental requirement. As one of the candidates for our spin rotator, we are developing the Wien-filter type. In this poster, the design of the Wien-filter type spin rotator for the low emittance muon beam will be presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB023  
About • paper received ※ 16 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB024 Beam-Gas and Beam-Thermal Photon Scattering in CEPC 626
 
  • S. Bai, J. Gao, H. Geng, D. Wang, Y. Wang, C.H. Yu, Y. Zhang
    IHEP, Beijing, People’s Republic of China
  • Y. Zhang
    University of Chinese Academy of Sciences, Beijing, People’s Republic of China
 
  The Circular Electron Positron Collider (CEPC) is a proposed Higgs factory with center of mass energy of 240 GeV to measure the properties of Higgs boson and test the standard model accurately. Beam loss background in detectors is an important topic at CEPC. Beam-Gas scattering (BG) and Beam-Thermal photon scattering (BTH), although not so serious as Radiative Bhabha scattering (RBB) and Beamstrahlung (BS), are also important components of the beam induced backgrounds at CEPC due to the beam lifetime. In this paper, we evaluated the beam-gas and beam-thermal photon scattering in simulation and designed collimators to suppress the radiation level on the machine and the detector.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB024  
About • paper received ※ 28 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB026 High-Quality Muon Beam Production Based on Superconducting Solenoids 630
 
  • Y. Bao, X. Li, Y. Li, Y.P. Song, X. Tong
    IHEP, Beijing, People’s Republic of China
 
  Funding: This work is supported by the Science Foundation of The Chinese Academy of Sciences and National Natural Science Foundation of China (No. 11875281)
In labs, muon beams are produced by protons hitting targets. The initial phase space of the muon beam is extremely large. In general, two types of muon collection methods have been used in the world. One is to put the muon production target in a superconducting solenoid, and low-energy muons are collected from the back of the target, then transported through a bent solenoid. In this way, a high-intensity muon beam can be collected, but the energy spread is wide and the beam polarization is low. For most muSR applications a surface muon beam with narrow energy bite and high polarization is required. Most muSR facilities are built with collecting magnets by the side of the target, in this way only a small fraction of muons with low emittance are collected and transported downstream. In this work we outline a muon collection method based on superconducting solenoid. Instead of using bent solenoids, a matching section with a dipole magnet is used to select muons with a certain momentum and match to downstream beamliines. A high-quality muon beam can be achieved with a high intensity and polarization. Such a method can be adapted to the MUSIC, Mu2e, and COMET muon beamlines after their dedicate experiments and convert the beamlines into a high quality muSR facility.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB026  
About • paper received ※ 30 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB027 Progress of HEPS Accelerator System Design 633
 
  • P. He, J.S. Cao, F.S. Chen, J. Chen, H. Dong, D.Y. He, Y. Jiao, W. Kang, C. H. Li, J.Y. Li, F. Long, H.H. Lu, X. Qi, Q. Qin, H. Qu, J.Q. Wang, G. Xu, J.H. Yue, J. Zhang, J.R. Zhang, P. Zhang
    IHEP, Beijing, People’s Republic of China
 
  The 4th generation ring-based light sources, HEPS (High Energy Photon Source) 7BA lattice has been de-veloped at IHEP. This is 6Gev, 200mA machine which has horizontal emittance Ɛh around 60pm.rad to gain the high brilliance photon beam. this compact lattice design bring so many engineering challenges for accelerator magnets, vacuum components, beam diagnotice, etc. This paper will present the noval lattice design and subsystem design progress.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB027  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB028 Application of WCM in Beam Commissioning of RCS in CSNS 636
 
  • M.T. Li, F. Li
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • Y.W. An, S.Y. Xupresenter, T.G. Xu
    IHEP, Beijing, People’s Republic of China
 
  Wall Current Monitor (WCM) is the only beam instru-ment in RCS of CSNS. It is utilized to derive many kinds of physics parameters during beam commissioning. The longitudinal phase distribution of the bunch over the boosting time is deduced for our future analyzation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB028  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB029 Longitudinal Tomography for Analysing the Longitudinal Phase Space Distribution in RCS of CSNS 639
 
  • M.T. Li
    IHEP CSNS, Guangdong Province, People’s Republic of China
  • Y.W. An, S.Y. Xupresenter, T.G. Xu
    IHEP, Beijing, People’s Republic of China
 
  It is proved that in the beam commissioning of the RCS of CSNS, the longitudinal optimization is vital for the promotion of the beam power. The WCM is the only beam instrument for the measurement of the longitudinal parameters. It is important for us to deduce the longitudi-nal phase space distribution, using the WCM data. The longitudinal tomography is applied, and some satisfying results have been obtained.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB029  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB031 Progress of Conceptual Study for the Accelerators of a 2-7GeV Super Tau Charm Facility at China 643
 
  • Q. Luo, W. Li, D.R. Xu
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  • W.W. Gao, J.Q. Lan
    Fujian University of Technology, Fuzhou, People’s Republic of China
 
  Funding: Supported by National Natural Science Foundation of China U1832169 and the Double Fist-Class University Project Foundation of USTC.
This paper shows the progress of the conceptual study for the accelerators of a super tau charm facility in China. Since the BEPCII will finish its historical mission in 5~10 years and its upgrade plan will only achieve a small luminosity enhancement of 3~5 times, a new next generation tau-charm collider will play an irreplaceable role in future high energy physics study. The luminosity of this successor is about 5×1034cm−2s−1 pilot and 1×1035cm−2s−1 nominal, with the electron beam longitudinally polarized at the IP. The general scheme of the accelerators and the beam pa-rameters are shown. Several key technologies such as beam polarization and beam emittance diagnostics are also discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB031  
About • paper received ※ 14 May 2019       paper accepted ※ 17 May 2019       issue date ※ 21 June 2019  
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MOPRB032 Interaction Section Lattice Design for a STCF Project 646
 
  • W.W. Gao, J.Q. Lan
    Fujian University of Technology, Fuzhou, People’s Republic of China
  • Q. Luopresenter
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  The Super Tau-Charm Factory (STCF) planning in China is characterized with high luminosity, wide energy range and high longitudinal polarized electron beam. In order to achieve high luminosity, this project will adopt the recently proposed collision scheme based on Large Piwinski angle and Crab Waist. In this paper, a preliminary lattice design of interaction region meeting the above collision scheme is described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB032  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB033 Preliminary Research of HOM for 100MHz Superconducting Cavity in the Pre-Research Project of HALS 649
SUSPFO070   use link to see paper's listing under its alternate paper code  
 
  • Y.G. Tang, L. Wang, C.-F. Wu
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  A 100MHz QWR superconducting cavity is researched in the pre-research project of Hefei Advanced Light Source (HALS). Higher order modes (HOM) damping is a big challenge for synchrotron radiation light source. In this paper, we first apply the novel choke mode structure to the 100MHz QWR (quarter wave resonator) cavity in order to damp the HOM. We identify the main harmful higher order modes. The HOMs in the QWR cavity are suppressed by optimizing the choke dimensions. The broadband HOM impedance spectrum of the cavity was also evaluated by calculating the beam induced wake potential in time domain. The results show that choke mode structure has a good HOM damping effect on the QWR cavity.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB033  
About • paper received ※ 25 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB036 Study on Beam-induced heating in injection section of Hefei Light Source 652
 
  • D.R. Xu, W. Xupresenter
    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  
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MOPRB041 Spin Resonance Strength in the Transparent Spin Mode of the NICA Collider 656
 
  • Y. Filatov, S.V. Vinogradov
    MIPT, Dolgoprudniy, Moscow Region, Russia
  • A.M. Kondratenko, M.A. Kondratenko
    Science and Technique Laboratory Zaryad, Novosibirsk, Russia
  • A.D. Kovalenkopresenter
    JINR, Dubna, Moscow Region, Russia
 
  To implement the polarization program at the NICA complex (Dubna, Russia) the novel mode of ion polarization control - the transparent spin mode - is planned to use. To set up the transparent spin mode in the NICA collider two solenoidal snakes will be placed in straights of the Multi Purpose Detector (MPD) and the Spin Physics Detector (SPD). The beam polarization at SPD will be controlled by means of ‘‘weak’’ solenoids. The main characteristic of the transparent spin mode is the spin resonance strength, which consists of two parts: a coherent part arising due to additional transverse and longitudinal fields on the beam trajectory deviating from the design orbit and an incoherent part associated with the particles’ betatron and synchrotron oscillations (beam emittances). The resonance strength allows one to formulate requirements on the magnitudes of the control solenoids’ fields. The theoretical analysis, calculation and spin tracking simulation of the spin resonance strength in the whole momentum range of the NICA collider are presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB041  
About • paper received ※ 01 May 2019       paper accepted ※ 17 May 2019       issue date ※ 21 June 2019  
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MOPRB043 Two-Beam Operation in DESIREE 659
 
  • A. Källberg, M. Björkhage, M. Blom, H. Cederquist, P. Reinhed, S. Rosén, H.T. Schmidt, A. Simonsson, H. Zettergren
    Stockholm University, Stockholm, Sweden
 
  The current status of DESIREE is described, with special emphasis on the setup for collision experiments with ions in both the two electrostatic rings - negative ions in one ring and positive in the other. By measuring the kinetic energy released in mutual neutralization reactions be-tween the two ions at collision energies close to zero eV in 3D, the population of different reaction channels has been obtained. The different steps necessary to set up the beams to get well controlled experimental properties are described as well as the principles behind our automatic optimization routines, which are extensively used with consistent result.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB043  
About • paper received ※ 02 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB045 Future High Power Proton Drivers for Neutrino Beams 662
 
  • D.C. Plostinar, M. Eshraqi, B. Gålnander
    ESS, Lund, Sweden
  • V.A. Lebedev
    Fermilab, Batavia, Illinois, USA
  • C.R. Prior
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • Y. Sato
    KEK, Ibaraki, Japan
  • J.Y. Tang
    IHEP, Beijing, People’s Republic of China
 
  Funding: ESSnuSB has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 7774.
Over the last two decades, significant efforts were made through several international studies to identify and develop technical solutions for potential Neutrino Factories and Superbeam Facilities. With many questions now settled, as well as clearer R&D needs, various proposals are being made for future facilities in China, Europe, Japan and North America. These include both developing and adapting existing machines as well as green-field solutions. In this paper, we review all the major accelerator programmes aimed at delivering high-power proton beams for neutrino physics.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB045  
About • paper received ※ 22 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB046 Status of the ESSnuSB Accumulator Design 666
 
  • Y. Zou, T.J.C. Ekelöf, M. Olvegård, R.J.M.Y. Ruber
    Uppsala University, Uppsala, Sweden
  • E. Bouquerel, M. Dracos
    IPHC, Strasbourg Cedex 2, France
  • M. Eshraqi, B. Gålnander
    ESS, Lund, Sweden
  • H.O. Schönauer, E.H.M. Wildner
    CERN, Geneva, Switzerland
 
  Funding: This project is supported by the COST Action CA15139 EuroNuNet. It has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 777419.
The 2.0 GeV, 5 MW proton linac for the European Spallation Source, ESS, will have the capacity to accelerate additional pulses and send them to a neutrino target, providing an excellent opportunity to produce an unprecedented high performance neutrino beam, the ESS neutrino Super Beam, ESSnuSB, to measure, with precision, the CP violating phase at the 2nd oscillation maximum. In order to comply with the acceptance of the target and horn systems that will form the neutrino super beam, the long pulses from the linac must be compressed by about three orders of magnitude with minimal particle loss, something that will be achieved through multi-turn charge-exchange injection in an accumulator ring. This ring will accommodate over 2·1014 protons, which means that several design challenges are encountered. Strong space charge forces, low-loss injection with phase space painting, efficient collimation, a reliable charge stripping system, and e-p instabilities are some of the important aspects central to the design work. This paper presents the status of the accumulator ring design, with multi-particle simulations of the injections procedure.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB046  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB048 Collimation System Studies for the FCC-hh 669
 
  • R. Bruce, A. Abramov, A. Bertarelli, M.I. Besana, F. Carra, F. Cerutti, M. Fiascaris, G. Gobbi, A.M. Krainer, A. Lechner, A. Mereghetti, D. Mirarchi, J. Molson, M. Pasquali, S. Redaelli, D. Schulte, E. Skordis, M. Varasteh Anvar
    CERN, Geneva, Switzerland
  • A. Abramov
    JAI, Egham, Surrey, United Kingdom
  • A. Faus-Golfe
    LAL, Orsay, France
  • M. Serluca
    IN2P3-LAPP, Annecy-le-Vieux, France
 
  The Future Circular Collider (FCC-hh) is being designed as a 100 km ring that should collide 50 TeV proton beams. At 8.3 GJ, its stored beam energy will be a factor 28 higher than what has been achieved in the Large Hadron Collider, which has the highest stored beam energy among the colliders built so far. This puts unprecedented demands on the control of beam losses and collimation, since even a tiny beam loss risks quenching superconducting magnets. We present in this article the design of the FCC-hh collimation system and study the beam cleaning through simulations of tracking, energy deposition, and thermo-mechanical response. We investigate the collimation performance for design beam loss scenarios and potential bottlenecks are highlighted.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB048  
About • paper received ※ 18 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB049 Study of Beam-Gas Interactions at the LHC for the Physics Beyond Colliders Fixed-Target Study 673
 
  • C. Boscolo Meneguolo, R. Brucepresenter, F. Cerutti, M. Ferro-Luzzi, M. Giovannozzi, A. Mereghetti, J. Molson, S. Redaelli
    CERN, Geneva, Switzerland
  • A. Abramov
    JAI, Egham, Surrey, United Kingdom
 
  Among several working groups formed in the framework of Physics Beyond Colliders study, launched at CERN in September 2016, there is one investigating specific fixed-target experiment proposals. Of particular interest is the study of high-density unpolarized or polarized gas target to be installed in the LHCb detector, using storage cells to enhance the target density. This work studies the impact of the interactions of 7 TeV proton beams with such gas targets on the LHC machine in terms of particle losses.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB049  
About • paper received ※ 17 April 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
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MOPRB050 Performance of the Collimation System During the 2018 Lead Ion Run at the Large Hadron Collider 677
 
  • N. Fuster-Martínez, R. Bruce, J.M. Jowett, A. Mereghetti, D. Mirarchi, S. Redaelli
    CERN, Meyrin, Switzerland
 
  As part of the Large Hadron Collider (LHC) heavy-ion research programme, the last month of the 2018 LHC run was dedicated to Pb ion physics. Several heavy-ion runs have been performed since the start-up of the LHC. These runs are challenging for collimation, despite lower intensities, because of the degraded cleaning observed compared to protons. This is due to the differences of the interaction mechanisms in the collimators. Ions experience fragmentation and electromagnetic dissociation that result in a substantial flux of off-rigidity particles that escape the collimation system. In this paper, the collimation system performance and the experience gained during the 2018 Pb ion run are presented. The measured performance is compared with the expectation from the Sixtrack-FLUKA coupling simulations and the agreement discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB050  
About • paper received ※ 07 May 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
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MOPRB051 Collimation System Upgrades for the High Luminosity Large Hadron Collider and Expected Cleaning Performance in Run 3 681
 
  • A. Mereghetti, R. Bruce, N. Fuster-Martinezpresenter, D. Mirarchi, S. Redaelli
    CERN, Geneva, Switzerland
 
  In the framework of the High-Luminosity Large Hadron Collider project (HL-LHC), the LHC collimation system needs important upgrades to cope with the foreseen brighter beams. New collimation hardware will be installed in two phases, the first one during the LHC second Long Shutdown (LS2), in 2019-20, followed by a second phase starting in 2024 (LS3). This paper reviews the collimation upgrade plans for LS2, focused on a first impedance reduction of the system, through the installation of collimators based on new materials, and the improvement of collimation cleaning, achieved by adding new collimators in the cold dispersion suppressor regions. The performance of the new system in terms of cleaning inefficiency for proton and lead ion beams is presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB051  
About • paper received ※ 06 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB052 Gamma Factory at CERN: Design of a Proof-of-Principle Experiment 685
 
  • Y. Dutheil, R. Alemany-Fernández, H. Bartosik, N. Biancacci, R. Bruce, P. Czodrowski, V. Fedosseev, B. Goddard, S. Hirlaender, J.M. Jowett, R. Kersevan, M. Kowalska, M. Lamont, D. Manglunki, J. Molson, A.V. Petrenko, M. Schaumann, F. Zimmermann
    CERN, Geneva, Switzerland
  • S. E. Alden, A. Bosco, S.M. Gibson, L.J. Nevay
    JAI, Egham, Surrey, United Kingdom
  • A. Apyan
    ANSL, Yerevan, Armenia
  • E.G. Bessonov
    LPI, Moscow, Russia
  • A. Bosco, S.M. Gibson, L.J. Nevay
    Royal Holloway, University of London, Surrey, United Kingdom
  • F. Castelli
    Università degli Studi di Milano, Milano, Italy
  • F. Castelli, C. Curatolo, L. Serafini
    INFN-Milano, Milano, Italy
  • K. Kroeger
    FSU Jena, Jena, Germany
  • A. Martens
    LAL, Orsay, France
  • V. Petrillo
    Universita’ degli Studi di Milano, Milano, Italy
  • M. Sapinski, T. Stöhlker
    GSI, Darmstadt, Germany
  • G. Weber
    IOQ, Jena, Germany
  • Y.K. Wu
    FEL/Duke University, Durham, North Carolina, USA
 
  The Gamma Factory (GF) initiative proposes to create novel research tools at CERN by producing, accelerating and storing highly relativistic partially stripped ion beams in the LHC rings and by exciting their atomic degrees of freedom by lasers, to produce high-energy photon beams. Their intensity would be several orders of magnitude higher than those of the presently operating light sources in the particularly interesting gamma-ray energy domain reaching up to 400 MeV. In this energy domain, the high-intensity photon beams can be used to produce secondary beams of polarized electrons, polarized positrons, polarized muons, neutrinos, neutrons and radioactive ions. Over the years 2017-2018 we have demonstrated that these partially stripped ion beams can be successfully produced, accelerated and stored in the CERN accelerator complex, including the LHC. The next step of the project is to build a proof of principle experiment in the SPS to validate the principal GF concepts. This contribution will present the initial conceptual design of this experiment along with its main challenge - the demonstration of the fast cooling method of partially stripped ion beams.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB052  
About • paper received ※ 19 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB055 First Partially Stripped Ions in the LHC (208Pb81+) 689
 
  • M. Schaumann, R. Alemany-Fernández, H. Bartosik, T. Bohl, R. Bruce, G.H. Hemelsoet, S. Hirlaender, J.M. Jowett, V. Kain, M.W. Krasny, J. Molson, G. Papotti, M. Solfaroli Camillocci, H. Timko, J. Wenninger
    CERN, Geneva, Switzerland
 
  The Gamma Factory initiative proposes to use partially stripped ion (PSI) beams as drivers of a new type of high intensity photon source. As part of the ongoing Physics Beyond Collider studies, initial beam tests with PSI beams have been executed at CERN. On 25 July 2018 lead ions with one remaining electron (208Pb81+) were injected and accelerated in the LHC for the first time. After establishing the injection and circulation of a few 208Pb81+ bunches, beam lifetimes of about 50 hours could be established at 6.5 TeV proton equivalent energy. This paper describes the setup of the beam tests and observations made.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB055  
About • paper received ※ 29 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB056 THz Radiator Based on Photonic Band Gap Crystal for SwissFEL 693
 
  • L. Shi, R. Ischebeck, S. Reiche
    PSI, Villigen PSI, Switzerland
 
  Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 701647.
The electromagnetic radiation in 1-20 THz has many unique properties when it interacts with matter due to its non-ionizing excitation in matter. Especially the dynamics of the excited matter can be probed with the help of X-ray pulses at a free electron laser facility, e.g. SwissFEL, to deepen our understanding of a wide range of phenomena. Due to its high research potential, various means of THz generation have been proposed and demonstrated. We investigate preliminarily here its generation based on a relativistic electron bunch and a photonic band gap crystal (PBG) made of dielectric rods. The PBG provides additional degrees of freedom for the THz pulse tuning. Additionally, the unwanted radiation parts can be damped by the structure in order to minimize the deleterious beam dynamics effects. The crystal also promises the integration of generation, filtering and coupling for transport into a single piece.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB056  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB057 An Approach to Alleviating Heavy Beam Loading Effect on the Synchrotron Machine Through the Existed Low Level RF Feedback System 697
 
  • L.-H. Chang, F.Y. Chang, M.H. Chang, S.W. Chang, L.J. Chen, F.-T. Chung, Y.T. Li, M.-C. Lin, Z.K. Liu, C.H. Lo, Ch. Wang, M.-S. Yeh, T.-C. Yu
    NSRRC, Hsinchu, Taiwan
 
  To pursue the highest brightness and intensity of the synchrotron light, the synchrotron machines are pushed to operate with as high as possible of the beam current. To suppress the heavy beam loading effects, the direct RF feedback is currently widely used. This paper provides an another approach to alleviating the heavy beam loading effects on machine operation. Different from the direct RF feedback technique, this approach need not add additional feedback loop to the existed RF feedback system. Applying a proper angle rotation to the I-Q error signals of the cavity voltage, before entering the existed feedback loop, is the only action required in this approach. The paper will explain the working mechanism and investigate the behaviour of this approach, through an example case, with numerical simulation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB057  
About • paper received ※ 16 April 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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MOPRB058 Collimation of Partially Stripped Ion Beams in the LHC 700
 
  • A. Abramov, L.J. Nevay
    JAI, Egham, Surrey, United Kingdom
  • R. Bruce, N. Fuster-Martínez, A.A. Gorzawski, M.W. Krasny, J. Molson, S. Redaelli, M. Schaumann
    CERN, Meyrin, Switzerland
 
  In the scope of the Physics Beyond Colliders studies, the Gamma Factory initiative proposes the use of partially stripped ions as a driver of a new type, high intensity photon source in CERN’s Large Hadron Collider (LHC). In 2018, the LHC accelerated and stored partially stripped 208-Pb-81+ ions for the first time. The collimation system efficiency recorded during this test was found to be prohibitively low. The worst losses were localised in the dispersion suppressor (DS) of the betatron-cleaning insertion. Analytic arguments and simulations show that the large losses are driven by the stripping of the remaining electron from the Pb nucleus by the primary collimators. The rising dispersion in the DS pushes the resulting off-rigidity, fully-stripped ions into the aperture of the superconducting magnets. In this study the measured loss maps are compared against results from simulations. Different mitigation strategies are outlined, including a dispersion suppressor (DS) collimator, crystal collimation or an orbit bump.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB058  
About • paper received ※ 10 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB059 Collimation of Heavy-Ion Beams in the HE-LHC 704
SUSPFO111   use link to see paper's listing under its alternate paper code  
 
  • A. Abramov, L.J. Nevay
    JAI, Egham, Surrey, United Kingdom
  • R. Bruce, M.P. Crouch, N. Fuster-Martínez, A. Mereghetti, J. Molson, S. Redaelli
    CERN, Meyrin, Switzerland
 
  A design study for a future collider to be built in the LHC tunnel, the High-Energy Large Hadron Collider (HE-LHC), has been launched as part of the Future Circular Collider (FCC) study at CERN. It would provide proton collisions at a centre-of-mass energy of 27 TeV as well as collisions of heavy ions at the equivalent magnetic rigidity. HE-LHC is being designed under the stringent constraint of using the existing tunnel and therefore the resulting lattice and optics differ in layout and phase advance from the LHC. It is necessary to evaluate the performance of the collimation system for ion beams in HE-LHC in addition to proton beams. In the case of ion beams, the fragmentation and electromagnetic dissociation that relativistic heavy ions can undergo in collimators, as well as the unprecedented energy per nucleon of the HE-LHC, requires dedicated simulations. Results from a study of collimation efficiency for the nominal lead ion (Pb-82-208) beams performed with the SixTrack-FLUKA coupling framework are presented. These include loss maps with comparison against an estimated quench limit as well as detailed considerations of loss spikes in the superconducting aperture for critical sections of the machine such as the dispersion suppressors.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB059  
About • paper received ※ 18 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB060 Simulating Novel Collimation Schemes for High-Luminosity LHC With Merlin++ 708
 
  • S.C. Tygier, R.B. Applebypresenter
    UMAN, Manchester, United Kingdom
  • R.J. Barlow, S. Rowan
    IIAA, Huddersfield, United Kingdom
 
  Due to the large stored beam energy in the HL-LHC new collimation technologies must be used to protect the machine. Active halo control of the proton beam halo with a Hollow Electron Lens can give a kick to protons at the edge of the beam without effecting the core. Various modes of operation are possible for example the electron lens can have a continuous current or it can be pulsed to different amplitudes for each passage of the proton beam. In this article we use Merlin++ simulations to show the performance of these modes for HL-LHC parameters. We also present recent simulations comparing scattering models in Merlin++.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB060  
About • paper received ※ 08 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB061 Simulations and Measurements of Coherent Synchrotron Radiation at the MAX-IV Short Pulse Facility 712
 
  • B.S. Kyle
    University of Manchester, Manchester, United Kingdom
  • R.B. Applebypresenter
    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  
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MOPRB062 nuSTORM Decay Ring 716
 
  • J.-B. Lagrange
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • R.B. Appleby, S.C. Tygier
    UMAN, Manchester, United Kingdom
  • J. Pasternak
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  Precise neutrino cross section measurements and search for sterile neutrinos can be done with neutrino beams produced from muons decaying in a storage ring due to its precisely known flavour content and spectrum. In the proposed nuSTORM facility pions would be directly injected into a racetrack storage ring, where circulating muon beam would be captured. The storage ring has three options: a FODO solution with large aperture quadrupoles, a racetrack FFA (Fixed Field Alternating gradient) using the recent developments in FFAs and a hybrid solution of the two previous options. Machine parameters, linear optics design and beam dynamics of the hybrid solution are discussed in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB062  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB063 Longitudinal Tomography in a Scaling FFA 719
 
  • D.J. Kelliher, C. Brown, J.-B. Lagrangepresenter, S. Machida, C.R. Prior, C.T. Rogers
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • Y. Ishi, Y. Kuriyama, H. Okita, T. Uesugi
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • S.L. Sheehy
    JAI, Oxford, United Kingdom
 
  In a synchrotron the rate of acceleration is limited by the ramp rate of the bending field. There is no such constraint in a Fixed Field alternating gradient Accelerator (FFA), allowing a much higher repetition rate and novel modes of operation such as beam stacking. It is of interest to obtain a picture of the longitudinal phase space from experimental data in order to diagnose the response of the beam to various RF programmes. Longitudinal tomography, already well established in synchrotrons, involves reconstructing the phase space using bunch monitor data obtained for a sufficient number of turns in a synchrotron oscillation. Here we reconstruct the longitudinal phase space using data from the 150 MeV scaling FFA at KURNS, Osaka, Japan.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB063  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB064 Precision Modelling of Energy Deposition in the LHC using BDSIM 723
SUSPFO121   use link to see paper's listing under its alternate paper code  
 
  • S.D. Walker, A. Abramov, S.T. Boogert, S.M. Gibson, L.J. Nevay, H. Pikhartova
    JAI, Egham, Surrey, United Kingdom
 
  A detailed model of the Large Hadron Collider (LHC) has been built using Beam Delivery Simulation (BDSIM) for studying beam loss patterns and is presented and discussed in this paper. BDSIM is a program which builds a Geant4 accelerator model from generic components bridging accelerator tracking routines and particle physics to seamlessly simulate the traversal of particles and any subsequent energy deposition in particle accelerators. The LHC model described here has been further refined with additional features to improve the accuracy of the model, including specific component geometries, tunnel geometry, and more. BDSIM has been extended so that more meaningful comparisons with other simulations and data can be made. Firstly, BDSIM can now record losses in the same way that SixTrack does: when a primary exceeds the limits of the aperture it is recorded as a loss. Secondly, by placing beam loss monitors (BLMs) within the BDSIM model and recording the simulated dose and energy deposition, it can be directly compared with real BLM data. These results are presented here and compared with SixTrack and BLM data from a typical fill in 2018.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB064  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB065 Enhancing Experimental Prospects With Low Energy Antiprotons 727
 
  • 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 the European Union’s Horizon 2020 research and innovation programme under the Marie SkłodowskaCurie grant agreement No 721559.
The Extra Low Energy Antiproton ring (ELENA) is a critical upgrade to the Antiproton Decelerator (AD) at CERN and saw the first beam in 2018. ELENA will significantly enhance the achievable quality of low energy antiproton beams and enable new experiments. To fully exploit the potential of this new facility, advances are required in numerical tools that can adequately model beam transport, life time and interaction, beam diagnostics tools and detectors to fully characterize the beam’s properties, as well as in novel experiments that take advantage of the enhanced beam quality that ELENA can provide. These research areas are in the heart of the pan-European research and training network AVA (Accelerators Validating Antimatter physics) which started in 2017. This contribution presents research results within AVA on the performance of ultra-thin diamond membranes, electron cooling and beam life time studies of low energy ion and antiproton beams, as well as efficient integration and performance optimization of cryogenic detectors in ELENA and associated trap experiments. These results are used to describe the optimum layout of a state-of-the-art low energy antiproton facility and associated experiments.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB065  
About • paper received ※ 13 May 2019       paper accepted ※ 17 May 2019       issue date ※ 21 June 2019  
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MOPRB067 High-gradient Single Cycle Terahertz Accelerating Structures 731
 
  • S.P. Antipov, E. Gomez, S.V. Kuzikov
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • A.A. Vikharev
    IAP/RAS, Nizhny Novgorod, Russia
 
  Recently, gradients on the order of 1 GV/m level have been obtained in a form of single cycle (~1 ps) THz pulses produced by conversion of a high peak power laser radiation in nonlinear crystals (~1 mJ, 1 ps, up to 3% conversion efficiency). These pulses however are broadband (0.1-5 THz) and therefore a new accelerating structure type is required. For electron beam acceleration with such pulses we propose arrays of parabolic focusing micro-mirrors with common central. These novel structures could be produced by a femtosecond laser ablation system developed at Euclid Techlabs. This technology had already been tested for production of several millimeters long, multi-cell structure which has been testing with electron beam. We also propose using of structures where necessary GV/m E-fields are excited by a drive bunch travelling in the corrugated waveguide. The radiated by drive bunch sequence of short range delayed wakes are guided in this case by metallic disks and reflected back being focused exactly at time when the witness bunch arrives.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB067  
About • paper received ※ 21 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB069 Generation of High Power Short Rf Pulses using an X-Band Metallic Power Extractor Driven by High Charge Multi-Bunch Train 734
 
  • J.H. Shao, M.E. Condepresenter, D.S. Doran, G. Ha, W. Liu, J.G. Power, C. Whiteford, E.E. Wisniewski
    ANL, Argonne, Illinois, USA
  • H.B. Chen, M.M. Peng, J. Shi, H. Zha
    TUB, Beijing, People’s Republic of China
  • C.-J. Jing
    Euclid TechLabs, LLC, Solon, Ohio, USA
  • J. Seok
    UNIST, Ulsan, Republic of Korea
 
  Short pulse two-beam acceleration (TBA) is a structure wakefield acceleration (SWFA) approach aiming to achieve gradient above 250 MV/m using rf pulses less than 20 ns. An X-band 11.7 GHz metallic power extractor has been developed as the power source to test accelerating structures in this extreme regime. The power extractor is designed to be driven by high charge bunches separated by 769.2 ps (9 times the X-band period) on an L-band 1.3 GHz beamline. In the recent experiment, ~280 MW rf pulses with 3 ns flat-top have been measured by a coaxial rf pickup when driven by 8-bunch trains with a total charge of ~500 nC. The power level is ~50% lower than the theoretical prediction and simulation. Experimental investigation suggests that the missing power was mainly caused by the multipacting issue inside the rf pickup, which could be eliminated by a newly-designed directional coupler.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB069  
About • paper received ※ 19 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB072 eRHIC in Electron-Ion Operation 738
 
  • W. Fischer, E.C. Aschenauer, E.N. Beebe, M. Blaskiewicz, K.A. Brown, D. Bruno, K.A. Drees, C.J. Gardner, H. Huang, T. Kanesue, C. Liu, M. Mapes, G.T. McIntyre, M.G. Minty, C. Montag, S.K. Nayak, M. Okamura, V. Ptitsyn, D. Raparia, J. Sandberg, K.S. Smith, P. Thieberger, N. Tsoupas, J.E. Tuozzolo, F.J. Willeke, A. Zaltsman, A. Zelenski
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy.
The design effort for the electron-ion collider eRHIC has concentrated on electron-proton collisions at the highest luminosities over the widest possible energy range. The present design also provides for electron-nucleon peak luminosities of up to 4.7·1033 cm-2s−1 with strong hadron cooling, and up to 1.7·1033 cm-2s−1 with stochastic cooling. Here we discuss the performance limitations and design choices for electron-ion collisions that are different from the electron-proton collisions. These include the ion bunch preparation in the injector chain, acceleration and intrabeam scattering in the hadron ring, path length adjustment and synchronization with the electron ring, stochastic cooling upgrades, machine protection upgrades, and operation with polarized electron beams colliding with either unpolarized ion beams or polarized He-3.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB072  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB074 Using an Energy Scan to Determine the Tunes and Orbit in the First FFA Girder of CBETA 742
 
  • C.M. Gulliford, N. Banerjee, A.C. Bartnik, J.A. Crittenden, P. Quigley
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • J.S. Berg
    BNL, Upton, Long Island, New York, USA
 
  This work reports the results of performing a scan of the beam energy performed during the Fractional Arc Test of the CBETA machine, a multi-pass SRF ERL featuring a non-scaling FFA return loop. The FFA arc consists of identical doublets that are designed to have an energy acceptance from 42 to 150 MeV, with a betatron phase advance (i.e., tune) per cell and periodic orbit position that depends on energy. In the CBETA fractional arc test, we transport the beam through 4 such cells (the first girder), and are capable of injecting beam in to the arc with energies as high as 59 MeV. By creating betatron oscillations in the arc, we can compute the phase advance per cell and periodic orbit position as a function of energy within that range. In addition, because the phase advance varies as a function of energy, the computation also provides an estimate of the offsets of the BPMs in that arc.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB074  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB075 Radiation Limits on Permanent Magnets in CBETA 745
 
  • V.O. Kostroun, C.M. Gullifordpresenter
    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  
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MOPRB076 CBETA Beam Commissioning Results 748
 
  • C.M. Gulliford, N. Banerjee, A.C. Bartnik, I.V. Bazarov, J.A. Crittenden, K.E. Deitrick, A. Galdi, G.H. Hoffstaetter, P. Quigley, K.W. Smolenski
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • J.S. Berg, S.J. Brooks, R.J. Michnoff, D. Trbojevic
    BNL, Upton, Long Island, New York, USA
 
  We report on the first results of commissioning CBETAwith a fully closed return loop. We repeat much of our early commissioning from the fractional arc test, namely setting up the injection system, calibrating the main linac, and steering the beam through the first splitter line. Most importantly, first results from sending the beam all the way through the FixedField Alternating gradient permanent magnet return arc are described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB076  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB077 Results From the CBETA Fractional Arc Test 751
 
  • C.M. Gulliford, N. Banerjee, A.C. Bartnik, J.A. Crittenden, P. Quigley
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • J.S. Berg
    BNL, Upton, Long Island, New York, USA
 
  We report on commissioning experiments of the Cornell Brookhaven Energy Recovery Test Accelerator Fractional Arc Test. The beam from the injector is accelerated by a linac with a 36 MeV design energy gain, is transported through a splitter line that uses conventional magnets, and finally into a four cell permanent magnet based fixed field alternating (FFA) gradient arc. We measure beam properties in the injector, calibrate the energy gain and phase of the linac cavities using time of flight to a BPM at the end of the linac. We scan individual cavity phases and pass beam through the cavities to determine the transverse offset of the individual cavities. We scan the beam position in the splitter BPMs to estimate and correct the nonlinearity in the BPM response. We tested our path length adjustment mechanism. We measure the dispersion and R56 in the FFA arc.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB077  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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MOPRB078 Beam Based Measurements of the CBeta Main Linac Cavity Alignment 755
 
  • C.M. Gulliford, A.C. Bartnik, J.A. Crittenden, P. Quigley
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • J.S. Berg
    BNL, Upton, Long Island, New York, USA
 
  Funding: This work was funded by NYSERDA, the New York State Energy Research and Development Agency.
Initial attempts at steering the beam through the CBETA main linac indicated the cavities were vertically offset with respect to the BPMs on either side of the linac.  In particular, manual alignment of the beam in the first and last cavities suggested a vertical offset of roughly 5 mm.  This work presents the results of beam based measurements of the individual cavity offsets taken during the CBETA Fractional Arc Test.  With only a single cavity powered at a time, beam was injected at several different vertical offsets, the RF phase was scanned over 360 degrees, and the beam position was measured at the end of the cryomodule. We analyzed the data in two ways. We first compute the RMS spread in the measurements at a given position, and considered the offset with the minimum RMS spread to be the cavity offset. We also fit the measurements at a given phase to a line as a function of initial displacement, and use a model for the transfer matrix of the cavity and downstream drift to compute the offset. The two methods agree well, resulting in an average vertical offset of the main linac cavities of 4.0 plus/minus 1 mm.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB078  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB080 Transient Beam Loading and Mitigation in JLEIC Collider Rings 758
 
  • J. Guo, R.A. Rimmer, H. Wangpresenter, S. Wang
    JLab, Newport News, Virginia, USA
  • J.D. Fox
    Stanford University, Stanford, California, USA
  • T. Mastoridis
    CalPoly, San Luis Obispo, California, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177, with additional support from U.S. DOE Award Number DE-SC-0019287
The Jefferson Lab Electron-Ion Collider (JLEIC) is an asymmetric high luminosity ring-ring collider proposed as the next major R&D facility for the nuclear physics community. Both of JLEIC’s electron and ion collider rings have high beam current with gaps serving the pur-poses of beam abort, ion clearing, etc. Such a time-varying beam loading in the RF cavities would generate modulation in cavity RF phase/voltage, causing cyclic shift of collision point and potential luminosity loss. We studied a few approaches to mitigate the RF phase modu-lation and IP shift, such as correcting the RF phase/voltage modulation with traditional LLRF feed-back, one-turn feedback (OTFB), or RF feedforward (FF); optimizing the bunch fill pattern to limit the RF phase/voltage modulation to a small fraction of the bunch trains in the collider ring; or matching the RF phase modulation in the two rings. The preliminary re-sults are discussed in this paper.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB080  
About • paper received ※ 23 May 2019       paper accepted ※ 24 May 2019       issue date ※ 21 June 2019  
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MOPRB081 Electron Beam’s Closed Orbit in the Crab Crossing Scheme of Future Electron-Ion Colliders 762
 
  • Y. Hao, V. Ptitsyn
    BNL, Upton, Long Island, New York, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  In crab-crossing collision geometry the closed orbit of the electron beam will be altered by the beam-beam interaction and the tilted head and tail of the ion beam. We will present the linear model to determine the closed orbit and compare with the simulation. Also, the relation of the closed orbit and the synchro-betatron resonance will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB081  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB082 Scaling Properties of the Synchro-Beta Resonance in Crab Crossing Scheme of Future Electron Ion Collider 766
 
  • Y. Hao, Y. Luo, V. Ptitsyn
    BNL, Upton, Long Island, New York, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  The synchro - beta resonance due to the beam-beam interaction was predicted by the strong-strong simulation in the future electron-ion collider designs. In this paper, we study the scaling properties of the degradation rate of this unwanted resonance. These studies motivated the possible countermeasures of the luminosity degradation associated with the resonance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB082  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB085 First Results from Commissioning of Low Energy RHIC Electron Cooler (LEReC) 769
 
  • D. Kayran, Z. Altinbas, D. Bruno, M.R. Costanzo, K.A. Drees, A.V. Fedotov, W. Fischer, M. Gaowei, D.M. Gassner, X. Gu, R.L. Hulsart, P. Inacker, J.P. Jamilkowski, Y.C. Jing, J. Kewisch, C.J. Liaw, C. Liu, J. Ma, K. Mernick, T.A. Miller, M.G. Minty, L.K. Nguyen, M.C. Paniccia, I. Pinayev, V. Ptitsyn, V. Schoefer, S. Seletskiy, F. Severino, T.C. Shrey, L. Smart, K.S. Smith, A. Sukhanov, P. Thieberger, J.E. Tuozzolo, E. Wang, G. Wang, A. Zaltsman, H. Zhao, Z. Zhao
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The brand new non-magnetized bunched beam electron cooler (LEReC) [1] has been built to provide luminosity improvement for Beam Energy Scan II (BES-II) physics program at the Relativistic Heavy Ion Collider (RHIC) BES-II [2]. The LEReC accelerator includes a photocathode DC gun, a laser system, a photocathode delivery system, magnets, beam diagnostics, a SRF booster cavity, and a set of Normal Conducting RF cavities to provide sufficient flexibility to tune the beam in the longitudinal phase space. This high-current high-power accelerator was successfully commissioned in period of March -September 2018. Beam quality suitable for cooling has been demonstrated. In this paper we discuss beam commissioning results and experience learned during commissioning.
[1] A. Fedotov et al., ’Status of bunched beam electron cooler LEReC’ in these proceedings.
[2] C.Liu et al., ’Improving luminosity of Beam Energy Scan II at RHIC’ in these proceedings.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB085  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB087 Proposal for a High Transformer Ratio CW Dielectric Accelerator 773
 
  • V. Litvinenko
    Stony Brook University, Stony Brook, USA
  • J.C. Brutus, Y.C. Jing, I. Pinayev, G. Wang
    BNL, Upton, Long Island, New York, USA
  • M.E. Conde, C.-J. Jing, J.G. Power
    ANL, Argonne, Illinois, USA
  • A. Kanareykin
    Euclid Beamlabs LLC, Bolingbrook, USA
  • N. Vafaei
    UCLA, Los Angeles, California, USA
 
  Advanced CW accelerators are one of high priority directions identified by Advanced Accelerator Concepts Research Roadmap Workshop Report *. High transformer ratio of beam-driven accelerators is critically important for cost-effective FEL systems. We present a proposed experiment for demonstrating a high transformer ratio CW dielectric accelerator using operational SRF accelerator built for Coherent electron Cooling experiment. This accelerator operates with CW electron beam comprised of 78 kHz train of electron bunches. Electron bunches with controllable longitudinal and charge up to 10 nC per bunch are generated in 1.25 MV SRF photo-electron gun. This bunches are ballistically compressed to duration of 10-to-30 psec and accelerated to 15 MeV in SRF linac**. Such bunches would be excellent drivers of high-transformer ratio DWA accelerators. In this paper we present expected performance of proposed CW DWA accelerator.
*Advanced Accelerator Concepts Research Roadmap Workshop Report, 2016,
*V.N. Litvinenko et al., In proc.of FEL’17, Santa Fe, NM, USA, August 20-25, 2017, p. 132
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB087  
About • paper received ※ 19 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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MOPRB088 Study of Fluctuations in Undulator Radiation in the IOTA Ring at Fermilab 777
SUSPFO128   use link to see paper's listing under its alternate paper code  
 
  • 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  
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MOPRB089 Experimental Study of a Single Electron in a Storage Ring via Undulator Radiation 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. Lobachpresenter
    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  
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MOPRB090 Simulation Challenges for eRHIC Beam-Beam Study 785
 
  • Y. Luo, F.J. Willeke
    BNL, Upton, Long Island, New York, USA
  • Y. Hao
    FRIB, East Lansing, USA
  • J. Qiang
    LBNL, Berkeley, California, USA
  • Y. Roblin, H. Zhang
    JLab, Newport News, Virginia, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The 2015 Nuclear Science Advisory Committee Long Rang Plan identified the need for an electron-ion collider (EIC) facility as a gluon microscope with capabilities beyond those of any existing accelerator complex. To reach the required high energy, high luminosity, and high polarization, the eRHIC design, based on the existing heavy ion and polarized proton collider RHIC, adopts a very small \beta-function at the interaction points, a high collision repetition rate, and a novel hadron cooling scheme. A full crossing angle of 22 mrad and crab cavities for both electron and proton rings are required. In this article, we will present the high priority R\&D items related to the beam-beam interaction studies for the current eRHIC design, the simulation challenges, and our plans and methods to address them. Recent progresses on this project are reported too.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB090  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB091 Combined Strong-Strong and Weak-Strong Beam-Beam Simulations for Crabbed Collision in eRHIC 788
 
  • Y. Luo, G. Bassi, M. Blaskiewicz, W. Fischer, Y. Hao, C. Montag, V. Ptitsyn, V.V. Smaluk, F.J. Willeke
    BNL, Upton, Long Island, New York, USA
  • K. Ohmi
    KEK, Ibaraki, Japan
  • J. Qiang
    LBNL, Berkeley, California, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In the eRHIC, to compensate the geometric luminosity loss, local crab cavities on both sides of the interaction points are to adopted. The previous strong-strong beam-beam simulations showed that the luminosity degradation depends on the crab cavity frequency, proton synchrotron tune, proton bunch length and so on. In this article, we apply a combined strong-strong and weak-strong beam-beam simulation to investigate the incoherent and coherent beam motions with crabbed collison, and to calculate more realistic beam emittance growth rates and luminosity degradation rate.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB091  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB092 Symplectic and Exact Tracking of Low Energy 197Au78+ in the Relativistic Heavy Ion Collider 791
 
  • Y. Luo, W. Fischer, F. Méot, G. Robert-Demolaize
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In the coming RHIC low energy scan, the electron cooling technique is to be used to cool the ions 197Au79+ with its energy range between 3.85~GeV/nucleon to 5.75~GeV/nucleon. To overlap the electron beam and the 197Au79+ beam at the cooling section, a recombination monitor is to be used to detect the maximum flux of 197Au78+ ions generated in the cooling section. In the previous studies, we tracked 197Au78+ ions through the RHIC lattice defined with 197Au79+ with an equivalent momentum deviation. In the article, we explode different symplectic ways to track 197Au78+ ions exactly. We calculate and compare the trajectories and loss map of 197Au78+ ions through the RHIC ring.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB092  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB093 eRHIC Electron Ring Design Status 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  
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MOPRB098 An Increased Extraction Energy Booster Complex for the Jefferson Lab Electron Ion Collider 797
 
  • E.A. Nissen
    JLab, Newport News, Virginia, USA
 
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, world-wide license to publish or reproduce this manuscript.
The proposed Jefferson Lab Electron Ion Collider (JLE-IC) envisions an ion complex composed of an ion linac, two booster synchrotrons and a collider ring. The evolving design of the JLEIC booster required an increase in the extraction energy of the booster from 8 to 12.1 GeV kinetic energy, necessitating two machines instead of one. The decision was also made to switch to warm magnets, thus increasing the total radius of the 8 GeV booster. The second booster is now the same size as the collider rings. In this work we present the new designs for JLEIC’s Low Energy Booster (LEB) and High Energy Booster (HEB).
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB098  
About • paper received ※ 14 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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MOPRB100 An Improved eRHIC Interaction Region Design Without High Field Nb3Sn Magnets 799
 
  • B. Parker, R.B. Palmer, H. Witte
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The IR magnets for the eRHIC Collider proposed at BNL must provide strong fields for the high momentum hadron beam and yet protect the nearby electron beam focusing channel from these fields. In our initial design the electron and hadron magnets were staggered so their respective cold masses did not overlap; however, this restricts the longitudinal space for the first hadron quadrupole and led to the challenge of making a high-field Nb3Sn main coil structure fit inside limited radial space within an external field active shield coil. In our new layout the crossing angle increased from 22 to 25 mrad and the electron and hadron cold masses are now side-by-side. This layout allows longer magnetic lengths for reducing the coil peak fields; NbTi conductor can now be used everywhere. Of course we must take care to control magnetic cross talk between neighboring apertures. One trick we will use to accomplish this is to maximize the yoke material thickness between the beams by tapering (i.e. change coil radius as a function of longitudinal position) some of the electron coils. The new eRHIC IR layout and magnet design is reported in this paper along with ongoing R&D to wind tapered coils.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB100  
About • paper received ※ 15 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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MOPRB103 A Phase Shifter for Multi-Pass Recirculating Proton LINAC 802
 
  • J. Qiang, L.N. Brouwer, S. Prestemon
    LBNL, Berkeley, California, USA
 
  Funding: This work was supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 and used computer resources at the National Energy Research Scientific Computing Center.
The multi-pass recirculating proton linac can significantly improve the usage efficiency of RF superconducting cavities by passing the proton beam through the same cavity multiple times. However, in order to achieve the multiple acceleration, synchronous conditions in phase have to be satisfied. In this paper, we propose a fixed field superconducting magnet system as a phase shifter to meet the synchronous conditions.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB103  
About • paper received ※ 09 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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MOPRB104 A Parameter Study for Improving the Performance of the Production Target for the Fermilab Muon g-2 Experiment 806
 
  • D. Stratakis
    Fermilab, Batavia, Illinois, USA
 
  The target station of the Muon g-2 Experiment is one of the central pieces for the production of secondary pions which eventually will decay to the desired mu-ons. In this paper, we report adjustments made to opti-mize its performance. For instance, in the simulation we vary the size of the primary incoming beam and examine its impact on the downstream production. We then compare this with the actual measured beam size upstream of the target. In addition, we examine the sensitivity in performance with the strength of the lithium lens for pion capture and the distance between lens and target. We compare measured data with simu-lation results.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB104  
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB105 Measurement and Analysis of Beam Phase-space Distributions for the Fermilab Muon Campus accelerator complex 810
 
  • A. Ramirez
    University of Houston, Houston, Texas, USA
  • D. Stratakispresenter
    Fermilab, Batavia, Illinois, USA
 
  The Muon g-2 experiment at Fermilab is tasked with measuring the muon’s anomalous magnetic moment with high precision. Since the experiment requires large amounts of muons, it is imperative to systematically study the behavior of the beam along the transport line. Unfortunately, the available diagnostics only provide beam information in X-Y space. For a complete evaluation, information of the phase-space is required. This paper demonstrates a technique to measure the beam phase-space distribution by using a set of beam profiles. First, we establish the theoretical framework that describes the principle of the technique. Next, we apply the technique at four different locations along the accelerator delivery line. Finally, we compare our findings to predictions from tracking simulations. Our results indicate that the beam phase-space volume is conserved, along the beam delivery line, suggesting minimal loses and linear transport as expected by design. Compared to the simulations, there is good agreement in both horizontal and vertical plane with the former being at the 4% level while the latter being in the 15% level. Our proposed technique is expected to provide a promising approach for optimizing injection and thereby improving the performance of the Muon g-2 Experiment.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB105  
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB106 3D Theory of Microbunched Electron Cooling for Electron-Ion Colliders 814
 
  • G. Stupakov, P. Baxevanis
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by the Department of Energy, Contract No. DE-AC02-76SF00515.
The Microbunched Electron Cooling (MBEC) * is a promising cooling technique that can find applications in future hadron and electron-ion colliders. A 1D model of MBEC has been recently developed in Ref. **. This model predicts the cooling time below two hours for eRHIC 255 GeV proton beams, when two amplification sections are used in the cooling system. In this work, we go beyond the 1D model of Ref. * and develop a realistic 3D theory of MBEC. Our approach is based on the analysis of the dynamics of microscopic 3D fluctuations in the electron and hadron beams during their interaction and propagation through the system. We derive an analytical expression for the cooling rate and optimize it for the parameters of eRHIC. Our analytical results are in reasonable agreement with simulations.
* D. Ratner. Phys. Rev. Lett. 111, 084802 (2013).
** G. Stupakov. PRAB 21, 114402 (2018)
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB106  
About • paper received ※ 29 April 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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MOPRB109 Cavity Design for the Updated eRHIC Crabbing System 818
 
  • S. Verdú-Andrés, Q. Wu
    BNL, Upton, Long Island, New York, USA
 
  Funding: Work supported by Brookhaven Science Associates LLC under contract no. DE-SC0012704 with the U.S. Department of Energy.
The electron-ion collider eRHIC proposed by Brookhaven National Laboratory includes a crabbing system to reestablish head-on collisions for a maximum geometric overlap of the colliding bunches. Since the last cavity design, the crossing angle has increased from 22 to 25 mrad to relax the field strength requirement in one of the IR magnets - increasing the deflecting kick required to collider the bunches head on - and one of the considered options is to have both proton and electron crab cavities work at 200 MHz. The present paper discusses the RF design of the 200 MHz crab cavities for the electron and hadron beams of eRHIC.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB109  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB110 Simulation Study of the Emittance Measurements in Magnetized Electron Beam 822
 
  • S.A.K. Wijethunga, J.R. Delayen, G.A. Krafft
    ODU, Norfolk, Virginia, USA
  • J. F. Benesch, F.E. Hannon, G.A. Krafft, M.A. Mamun, G.G. Palacios Serrano, M. Poelker, R. Suleiman, S. Zhangpresenter
    JLab, Newport News, Virginia, USA
 
  Funding: This work is supported by the Department of Energy, Laboratory Directed Research and Development funding, under contract DE-AC05-06OR23177
Electron cooling of the ion beam is key to obtaining the required high luminosity of proposed electron-ion colliders. For the Jefferson Lab Electron Ion Collider, the expected luminosity of 1034 〖 cm〗-2 s-1 will be achieved through so-called ’magnetized electron cooling’, where the cooling process occurs inside a solenoid field, which will be part of the collider ring and facilitated using a circulator ring and Energy Recovery Linac (ERL). As an initial step, we generated magnetized electron beam using a new compact DC high voltage photogun biased at -300 kV employing an alkali-antimonide photocathode. This contribution presents the characterization of the magnetized electron beam (emittance variations with the magnetic field strength for different laser spot sizes) and a comparison to GPT simulations.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB110  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPRB116 Laser Sculpted Cool Proton Beams 826
 
  • S.M. Gibson, L.J. Nevay
    Royal Holloway, University of London, Surrey, United Kingdom
  • S. E. Alden, S.M. Gibson, L.J. Nevay
    JAI, Egham, Surrey, United Kingdom
 
  Funding: We acknowledge support by STFC grant ST/P003028/1
Hydrogen ion accelerators, such as CERN’s Linac4, are increasingly used as the front end of high power proton drivers for high energy physics, spallation neutron sources and other applications. Typically, a foil strips the hydrogen ion beam to facilitate charge-exchange injection of protons into orbits of high energy accelerators, in which the resulting emittance is dominated by phase-space painting. In this paper, a new method to laser extract a narrow beam of neutralised hydrogen from the parent H ion beam is proposed. Subsequent foil stripping and capture of protons into a storage ring generates cool proton bunches with significantly reduced emittance compared to the parent beam. The properties of the extracted proton beam can be precisely controlled and sculpted by adjusting the optical parameters of the laser beam. Recirculation of the parent beam allows time for space-charge effects to repopulate the emittance phase space prior to repeated laser extraction. We present particle tracking simulations of the proposed scheme, including the laser-particle interaction with realistic optical parameters and show the resulting emittance is reduced. Developments for an experimental demonstration of a laser controlled particle beam are outlined. In principle, the proposed scheme could considerably reduce the emittance of protons bunches injected into an accelerator, such as the LHC.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPRB116  
About • paper received ※ 16 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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