Keyword: polarization
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MOPGW030 New Analytical Derivation of Group Velocity in TW Accelerating Structures cavity, dipole, simulation, coupling 155
 
  • M. Behtouei, M. Migliorati, L. Palumbo
    Sapienza University of Rome, Rome, Italy
  • L. Faillace
    Universita’ degli Studi di Milano & INFN, Milano, Italy
  • B. Spataro
    INFN/LNF, Frascati, Italy
 
  Ultra high-gradient accelerating structures are needed for the next generation of compact light sources. In the framework of the Compact Light XLS project, we are studying a high harmonic traveling-wave accelerating structure operating at a frequency of 35.982 GHz, in order to linearize the longitudinal space phase. In this paper, we propose a new analytical approach for the estimation of the group velocity in the structure and we compare it with numerical electromagnetic simulations that are carried out by using the code HFSS in the frequency domain.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW030  
About • paper received ※ 08 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPGW060 Cherenkov Radiation at Off-Axis Bunch Passage Through Dielectric Concentrator target, radiation, diagnostics, site 225
 
  • S.N. Galyamin, A.V. Tyukhtin, V.V. Vorobev
    Saint Petersburg State University, Saint Petersburg, Russia
 
  Funding: Work supported by the Grant from Russian Foundation for Basic Research (No. 17-52-04107).
Development of tunable systems for non-invasive bunch diagnostics is a modern trend in accelerator physics. Certain dielectric targets are considered in this context, for example, dielectric cones or prisms. Moreover, all-dielectric target which increase the radiated Cherenkov field near the predetermined focus up to several orders of magnitude has been described* and field near its focus and sensitivity of this target have been analyzed**. Here we consider a non-symmetrical case where charge trajectory has a shift with respect to structure axis. We develop analytical approach for description of Cherenkov radiation, perform three-dimensional simulations and compare the results.
* S.N. Galyamin and A.V. Tyukhtin, Phys. Rev. Lett., 113, 064802 (2014).
** S.N. Galyamin and A.V. Tyukhtin, Nucl. Instr. Meth. Phys. Res. B. 2017. V. 402. P.185-189.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW060  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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MOPMP012 Concepts of Longitudinally Polarized Electron and Positron Colliding Beams in the Circular Electron Positron Collider positron, resonance, electron, wiggler 445
 
  • Z. Duan, J. Gao, X.P. Li, D. Wang, Y. Wang, W.H. Xia, Q.J. Xu, C.H. Yu, Y. Zhang
    IHEP, Beijing, People’s Republic of China
 
  Funding: Work supported by National Key Research and Development Program of China (No.2018YFA0404300).
This paper reports some preliminary study into the imple- mentation of longitudinally polarized e+/e colliding beams in the Circular Electron Positron Collider, at a center of mass energy of 91 GeV as a Z factory and energies beyond.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPMP012  
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 emittance, rfq, experiment, acceleration 622
 
  • 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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MOPRB026 High-Quality Muon Beam Production Based on Superconducting Solenoids target, proton, experiment, solenoid 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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MOPRB041 Spin Resonance Strength in the Transparent Spin Mode of the NICA Collider solenoid, resonance, proton, 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. Kovalenko
    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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MOPRB093 eRHIC Electron Ring Design Status electron, storage-ring, solenoid, radiation 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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MOPTS011 Spin Motion Perturbation Effect on the EDM Statistic in the Frequency Domain Method betatron, dipole, storage-ring, lattice 861
 
  • A.E. Aksentyev
    FZJ, Jülich, Germany
  • A.E. Aksentyev
    MEPhI, Moscow, Russia
  • A.E. Aksentyev, V. Senichev
    RAS/INR, Moscow, Russia
 
  The spin precession axis of a particle involved in betatron motion precesses about the invariant spin axis defined on the closed orbit (CO). This precession can be observed in polarization data as a rapid, small-amplitude oscillation on top of the major effect oscillation caused by the precession of spin about the CO axis. The frequency of this latter oscillation is used in the Frequency Domain (FD) methodology as the EDM observable. [*] It is estimated by fitting polarimetry data by a sine function; the rapid oscillations, therefore, constitute a model specification error. This model error might introduce a bias into the frequency estimate. In the present work we investigate the effect of the spin precession axis motion on measurement data and fit quality, and conclude that it is not only insignificant (with regard to data perturbation) compared to spin tune variation, but is also controllable via the application of a Spin Wheel.
[*] Senichev Y, Aksentev A, Ivanov A, Valetov E. Frequency domain method of the search for the deuteron electric dipole moment in a storage ring with imperfections. arXiv:171106512. 2017 Nov 17
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPTS011  
About • paper received ※ 08 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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TUPGW033 Status of Test-Accelerator as Coherent THz Source (t-ACTS) at ELPH, Tohoku University radiation, electron, undulator, FEM 1475
 
  • S. Kashiwagi, H. Hama, F. Hinode, K. Kanomata, S. Miura, N. M. Morita, T. Muto, I. Nagasawa, K. Nanbu, S. Ninomiya, H. Saito, K. Takahashi, H. Yamada
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
 
  A test-Accelerator as Coherent Terahertz Source (t-ACTS) has been under development at the Research Center for Electron Photon Science (ELPH), Tohoku University, in which an intense coherent terahertz radiation is generated from the femtosecond electron pulses. Velocity bunching scheme in a traveling accelerating structure is employed to generate femtosecond electron pulses, and the generation of femtosecond electron pulses was confirmed by spectrum analysis of coherent transition radiation using Michelson interferometer. Coherent transition radiation and coherent undulator radiation in the terahertz (THz) region from the short electron pulses has been demonstrated, and their characteristics such as frequency spectrum, spatial distribution and polarization were measured and compared with theoretical calculations. We have succeeded to generate the coherent transition radiation up to approximately 5 THz and the coherent undulator radiation with narrow bandwidth from 2.6 to 3.4 THz. At present, development of a variable polarized THz light source using a crossed-undulator system is being carried out. In addition, we are developing a nondestructive beam monitor using Cherenkov radiation emitted from the electron pulses. The status of t-ACTS will be presented in this conference.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW033  
About • paper received ※ 17 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPGW069 Insertion Devices for the Day-One Beamlines of ILSF undulator, vacuum, wiggler, storage-ring 1561
 
  • M. Hadad
    Shahid Beheshti University, Tehran, Iran
  • S. Dastan, M. Hadad, J. Rahighi, M. Razazian, F. Saeidi, S. Yousefnejad
    ILSF, Tehran, Iran
 
  The Iranian Light Source Facility (ILSF) is a new 3 GeV synchrotron radiation laboratory with ultralow emittance of 270 pm-rad, which is in the design stage. Seven beamlines are planned to start operation with several different insertion devices installed in the storage ring either from "day one" or within the first year of operation. The most operational undulator for polarized radiations -Apple II- has been deliberated for the solid state electron spectroscopy, the Spectromicroscopy and the ARPES beamlines. The hybrid wigglers for the XPD and the EXAFS beamlines and in-vacuum undulators for Macromolecular Crystallography and SCD beamlines have been chosen too. The emission of these IDs covers a wide spectral range extending from hard X-rays to UV. Pre-design of the IDs were already done in ILSF. The main parameters of magnetic design as well as radiation parameters for the first phase of ILSF insertion devices have been described in this paper.
farhad.saeidi@ipm.ir
saeidi.farhad@gmail.com
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW069  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPRB003 Virtual Shimming and Magnetic Measurements of two Long Period APPLE-II Undulators at the Canadian Light Source MMI, undulator, multipole, storage-ring 1679
 
  • C.K. Baribeau, T.M. Pedersen, M.J. Sigrist
    CLS, Saskatoon, Saskatchewan, Canada
 
  Assembly and shimming have completed for a pair of long period APPLE-II type elliptically polarized undulators, QP-EPU180 and EPU142, at the Canadian Light Source. Both devices were shimmed using a weighted cost single-objective simulated annealing algorithm, with shims generated iteratively based on Hall probe and flipping coil data. In this paper we present detailed measurements on the two EPUs, including their magnetic and spectral performance across a wide range of gap and polarization operating points, as well as measured and predicted changes in field due to the virtual shimming.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB003  
About • paper received ※ 08 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPRB005 Photon Polarisation Modelling of APPLE-II EPUs photon, undulator, operation, simulation 1687
 
  • M.J. Sigrist, C.K. Baribeau, T.M. Pedersen
    CLS, Saskatoon, Saskatchewan, Canada
 
  The CLS is currently commissioning two APPLE-II in-sertion devices (IDs), see [1], and constructing two more that allow for operation in ’universal mode’, i.e. selecting arbitrary photon polarisation parameters. Two of these devices will operate in the soft x-ray range where there is expected to be a significant change to polarisation at the sample due to transmission effects of the beam line op-tics. Arbitrary polarisation selection of the ID will counter transmission effects and enable circular polarisation at the sample position. A polarisation model of the device is derived which allows for the calculation of both the Stokes parameters and photon energy for any set point of ID gap and phase. Numerical solutions of these equa-tions allow the calculation of gap and phase set points for any desired photon energy or polarisation. The results of the polarisation model are compared with numerical simulations of the synchrotron radiation calculated using measured magnetic fields at various polarisation modes.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB005  
About • paper received ※ 13 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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TUPRB006 Effect of Electrostatic Deflectors and Fringe Fields on Spin for Hadron Electric Dipole Moment Measurements on Storage Rings storage-ring, dipole, controls, vacuum 1691
 
  • J. Michaud, J.-M. De Conto, Y. Gómez Martínez
    LPSC, Grenoble Cedex, France
 
  The observed matter-antimatter asymmetry in the universe cannot be explained by the Standard Model. An explanation is a non-vanishing Electric Dipole Moment of subatomic particles. The JEDI (Jülich Electric Dipole moment Investigations) collaboration is preparing a direct EDM measurement of protons and deuterons first at the storage ring COSY (COoler SYnchrotron) and later at a dedicated storage ring. To achieve this, one needs a stable polarization, i.e. around 1000 seconds for spin coherence time. One source of decoherence are the electrostatic deflectors, and this must be quantified. We developed an analytical model for cylindrical deflectors, including fringe fields, and the associated beam and spin transfer functions, integrated over the deflector. All boundaries (including ground) are considered, giving a realistic, accurate field map up to any order. We get universal formulas, the only adjustable parameter being the deflector gap/radius ratio, all other terms being numerical. This has been implemented in BMAD. We present the mathematical, physical and numerical developments, as well as results for a proton storage ring.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB006  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPRB024 A Concept for Upgrade of FLASH2 Undulator Line undulator, FEL, electron, operation 1736
 
  • E. Schneidmiller, B. Faatz, I. Hartl, S. Schreiber, M. Tischer, M. Vogt, M.V. Yurkov, J. Zemella
    DESY, Hamburg, Germany
  • W. Wurth
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
 
  FLASH is the first soft X-ray FEL user facility, routinely providing brilliant photon beams for users since 2005. There are plans to upgrade both existing undulator lines of this facility, FLASH1 and FLASH2. FLASH1 will mainly operate in XUV range in seeding and SASE modes, while FLASH2 will use the standard SASE regime as well as new lasing concepts aiming at production of brilliant photon beams on the fundamental and harmonics down to 1nm. In this paper we present a concept for FLASH2 upgrade, and discuss different advanced options.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB024  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPRB033 Fixed-gap Undulators for Elettra and FERMI undulator, electron, FEL, operation 1760
 
  • B. Diviacco, R. Bracco, D. Millo
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
 
  In the context of an R&D program on alternative undulator schemes, two fixed-gap, linearly polarised, adjustable-phase undulators (APUs) were built and successfully tested, the first on the FERMI free electron laser, the second on the Elettra storage ring. The latter is now in regular operation for the ALOISA surface science beam line. As a further elaboration on the fixed-gap concept, two elliptically polarised undulators (EPUs) are now being developed for FERMI and for Elettra. We have also started the construction of a double period APU providing an extended tuning range to the TwinMic soft X-Ray microscopy beam line. We present here the main design and construction aspects of the new undulators under development.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB033  
About • paper received ※ 09 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPRB037 Experimental Demonstration of Vector Beam Generation With Tandem Helical Undulators undulator, experiment, radiation, simulation 1766
 
  • S. Matsuba
    HSRC, Higashi-Hiroshima, Japan
  • M. Fujimoto, M. Katoh
    UVSOR, Okazaki, Japan
  • M. Hosaka
    Nagoya University, Nagoya, Japan
  • K. Kawase
    QST, Tokai, Japan
  • T. Konomi, N. Yamamoto
    KEK, Ibaraki, Japan
  • A. Miyamoto
    Toshiba, Yokohama, Japan
  • S. Sasaki
    ANL, Argonne, Illinois, USA
 
  Vector beam is a light beam with spatially modulated polarization state across the beam. Particular examples of vector beam are radial and azimuthal polarization which have donut-shaped intensity and radially and azimuthally oriented linear polarization state. Vector beam has long been interest in the laser community and it is well known that vector beam can be created by superposing two optical vortex beams which have spiral wave fronts. It has been demonstrated that optical vortex beam can be generated from a helical undulator as harmonics. Therefore, we propose a scheme to generate vector beam by superposing two optical vortex beams from two helical undulators in tandem, based on the principle of the ’crossed undulator’. The experiment was carried out at UVSOR BL1U. In this paper, we describe the principle and the experimental details.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB037  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPRB038 Characteristics of Polarized Coherent Radiation in Thz Region From a Crossed-Undulator undulator, radiation, experiment, electron 1769
 
  • H. Saito, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, N. M. Morita, T. Muto, I. Nagasawa, K. Nanbu, S. Ninomiya, K. Takahashi, H. Yamada
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
 
  A variable polarized THz light source using a crossed-undulator configuration has been developed at Research Center for Electron Photon Science (ELPH), Tohoku University. It consists of two planar undulators of which deflecting planes cross at right angles and a phase shifter for phase adjustment. Polarization of the crossed-undulator has observation angle dependence due to that of radiation wavelength and optical path length difference between two radiations. That limits an angular range maintaining the identical polarization state. Assuming undulator parameters for our experiment (a fundamental frequency 1.9 THz and a number of periods seven) degree of circular polarization larger than 0.9 can be obtained only in the range of 2.2 mrad, i. e. 13% of the radiation angular spread.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB038  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPRB047 Proposal of the Reflection Hard X-Ray Self-Seeding at the SHINE Project FEL, undulator, photon, lattice 1792
 
  • T. Liu, C. Feng
    SARI-CAS, Pudong, Shanghai, People’s Republic of China
 
  FEL self-seeding has been demonstrated a great advantage for the generation of a fully coherent and high brightness X-ray pulse experimentally. Generally, transmission monochromators with single crystal are adopted worldwide, such as LCLS, PAL-XFEL and European-XFEL. Recently, the self-seeding scheme based on a reflection monochromator with a double-crystal is proposed and demonstrated at SACLA successfully. In view of several potential advantages of the reflection type, here we give the proposal of the reflection monochromator based self-seeding and enable the application on the SHINE project. This manuscript is mainly focus on monochromator schemes at SHINE, instead of FEL simulations. We will present considerable schemes based on the specific undulator line.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB047  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPRB072 Compact APPLE X for Future SXL FEL and 3 GeV Ring at MAX IV Laboratory undulator, photon, vacuum, FEL 1833
 
  • H. Tarawneh, P. N’gotta, L.K. Roslund, A. Thiel, K. Åhnberg
    MAX IV Laboratory, Lund University, Lund, Sweden
 
  An overview of the design of compact elliptically polarizing undulator with small round magnetic gap to provide full polarization control of synchrotron radiation in a more cost effective manner and consuming less built in space than the state of the art devices. This type of undulator is meant as source for the potential future Soft X-ray (SXL) FEL beamline using the linear accelerator at MAX IV. In addition, it offers new capabilities for future beamlines at the 3 GeV ring to use full polarization control to photon energies using the fundamental harmonic which are not attainable with today’s technology of the out-of-vacuum insertion devices at 3 GeV beam energy.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB072  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPRB102 Numerical Study of the Delta II Polarizing Undulator for LCLS II undulator, simulation, electron, laser 1899
 
  • K. Tian, H.-D. Nuhn
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by US Department of Energy Contract DE-AC03-76SF00515.
The Delta undulator has been operated successfully in LCLS with full control of the polarization mode and K value of the device. In LCLS II, a new Delta II undulator will be based on a similar design but with some differences. In this paper, we will present numerical simulation results that provide guidance to choose the geometric shape of the magnet poles and define the required tolerance for assembling the undulator magnets.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB102  
About • paper received ※ 10 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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TUPTS108 Numerical Simulations of RHIC FY17 Spin Flipper Experiments simulation, resonance, experiment, dipole 2174
 
  • P. Adams, H. Huang, J. Kewisch, C. Liu, F. Méot, P. Oddo, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, T. Roser
    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.
Spin flipper experiments during RHIC Run 17 have demonstrated the 97% effectiveness of polarization sign reversal during stores. Zgoubi numerical simulations were setup to reproduce the experimental conditions. A very good agreement between the experimental measurements and simulation results was achieved at 23.8GeV, thus the simulations are being used to help optimize the various Spin Flipper parameters. The ultimate goal for these simulations is to serve as guidance towards a perfect flip at high energies to allow a routine Spin Flipper use during physics runs.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPTS108  
About • paper received ※ 13 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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WEPMP048 Development of Spin Rotator and an Absolute Polarimeter for Polarized He-3 at BNL dipole, solenoid, scattering, target 2440
 
  • D. Raparia, G. Atoian, S. Ikeda, R.F. Lambiase, M. Okamura, A. Poblaguev, J. Ritter, S. Trabocchi, A. Zelenski
    BNL, Upton, Long Island, New York, USA
  • R. Milner, M. M. Musgrave
    MIT, Cambridge, Massachusetts, USA
 
  Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
EBIS Preinjector will provide longitudinally polarized 3He++ ions with about 80% polarization and 5.1011 particles per bunch at 6 MeV, which must be rotated to vertical direction before it ions are injected into the Booster. The 3He++ longitudinal polarization is first rotated to the transverse direction by the 21.5° bending magnet. Then the solenoid spin-rotator rotates the spin to the vertical direction. The spin-rotator will be a pulsed solenoid with a reversible field to enable spin flips. The vertically polarized beam will be returned back to the straight HEBT line by the system of three dipole magnets after the spin rotator solenoid. The low-energy polarimeter can be installed in the straight beam line section after the second dipole magnet. To measure transverse (vertical) polarization of the 3He beam at 5-6 MeV, the spin correlated asymmetry of 3He scattering on a 4He gas target (~5 Torr) will be measured with left/right symmetric strip detectors. Paper will present status of the project.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPMP048  
About • paper received ※ 19 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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WEPGW012 Vertical Beam Size Measurement Methods at the BESSY II Storage Ring and their Resolution Limits diagnostics, storage-ring, electron, detector 2491
 
  • M. Koopmans, F. Armborst, J.G. Hwang, A. Jankowiak, P. Kuske, M. Ries, G. Schiwietz
    HZB, Berlin, Germany
 
  With the VSR upgrade for the BESSY II electron storage ring* bunch resolved diagnostics are required for machine commissioning and to ensure the long-term quality and stability of operation. For transverse beam size measurements we are going to use an interferometric method, which will be combined with a fast gated intensified CCD camera at a subsequent stage. A double-slit interferometer method has already been verified successfully at BESSY II**. In addition first 2D bunch resolved measurement tests have been performed at the dedicated diagnostics beamline for bunch length measurements. Measurements of the interferometer and X-ray pinholes as function of a vertical electron beam excitation are compared in this paper.
* A. Jankowiak et al., Germany, June 2015. DOI: 10.5442/R0001
** M. Koopmans et al., in Proc. IPAC’17, paper MOPAB032, 2017
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW012  
About • paper received ※ 09 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPGW113 Propose a Non-Destructive Stern-Gerlach Apparatus for Measuring the Spin Polarization of Electron Beam electron, quadrupole, simulation, software 2763
 
  • W. Liu, E. Wang
    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.
Mott polarimeter is used for measuring the spin polarization of <10 MeV electron beam destructively. We propose a nondestructive spin polarization measurement device for electron beam based on Stern-Gerlach effect, which include a magnetic quadrupole, Lorenz force compensated electric quadrupole and Beam position monitor. The magnetic quadrupole provides a spin-magnetic interaction force (or Stern-Gerlach force) for the spin polarized electrons. The electric quadrupole provides an electric field force for electrons to offset the Lorentz force induced by the magnetic quadrupole. So that the polarized electron beam only experience the gradient force in the device, which has ability to split the spin polarized electron beam. By measuring the split spin polarized electrons using high resolution beam position monitor, the polarization of electron beam can be calculated. We will present the theoretical analysis and calculation of electron motion in this device.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW113  
About • paper received ※ 01 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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WEPGW122 EXPERIMENTAL VERIFICATION OF TRANSPARENT SPIN MODE IN RHIC collider, controls, experiment, resonance 2783
 
  • V.S. Morozov, Y.S. Derbenev, F. Lin, Y. Zhang
    JLab, Newport News, Virginia, USA
  • P. Adams, H. Huang, F. Méot, V. Ptitsyn, W.B. Schmidke
    BNL, Upton, Long Island, New York, USA
  • Y. Filatov
    MIPT, Dolgoprudniy, Moscow Region, Russia
  • H. Huang
    ODU, Norfolk, Virginia, USA
  • A.M. Kondratenko, M.A. Kondratenko
    Science and Technique Laboratory Zaryad, Novosibirsk, Russia
 
  Funding: Supported in part by the U.S. DoE under Contract No. DE-AC05-06OR23177 and by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DoE.
High electron and ion polarizations are some of the key design requirements of a future Electron Ion Collider (EIC). The transparent spin mode, a concept inspired by the figure 8 ring design of JLEIC, is a novel technique for preservation and control of electron and ion spin polarizations in a collider or storage ring. It makes the ring lattice "invisible" to the spin and allows for polarization control by small quasi-static magnetic fields with practically no effect on the beam’s orbital characteristics. It offers unique opportunities for polarization maintenance and control in Jefferson Lab’s JLEIC and in BNL’s eRHIC. The transparent spin mode has been demonstrated in simulations and we now plan to test it experimentally. We present a design of an experiment using a polarized proton beam stored in one of the RHIC rings. In the experiment, one of the RHIC rings is configured in the transparent spin mode by aligning the axes of its two Siberian snakes. The experiment goals, procedures, hardware requirements and expected results are presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW122  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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WEPGW124 Spin Response Function for Spin Transparency Mode of RHIC resonance, collider, controls, lattice 2791
 
  • V.S. Morozov, Y.S. Derbenev, F. Lin, Y. Zhang
    JLab, Newport News, Virginia, USA
  • P. Adams, H. Huang, F. Méot, V. Ptitsyn, W.B. Schmidke
    BNL, Upton, Long Island, New York, USA
  • Y. Filatov
    MIPT, Dolgoprudniy, Moscow Region, Russia
  • H. Huang
    ODU, Norfolk, Virginia, USA
  • A.M. Kondratenko, M.A. Kondratenko
    Science and Technique Laboratory Zaryad, Novosibirsk, Russia
 
  Funding: Supported by the U.S. DoE under Contracts No. DE-AC05-06OR23177 and DE-AC02-98CH10886.
In the Spin Transparency (ST) mode of RHIC, the axes of its Siberian snakes are parallel. The spin tune in the ST mode is zero and the spin motion becomes degenerate: any spin direction repeats every particle turn. In contrast, the lattice of a conventional collider determines a unique stable periodic spin direction, so that the collider operates in the Preferred Spin (PS) mode. Contributions of perturbing magnetic fields to the spin resonance strengths in the PS mode are usually calculated using the spin response function. However, in that form, it is not applicable in the ST mode. This paper presents a response function formalism expanded for the ST mode of operation of conventional colliders with two identical Siberian snakes in the highly-relativistic limit. We present calculations of the spin response function for RHIC in the ST mode.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW124  
About • paper received ※ 01 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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THPGW044 Highly Stable Linearly Polarized Arbitrary Temporal Shaping of Picosecond Laser Pulses laser, controls, experiment, flattop 3682
 
  • F. Liu, S. Huang, K.X. Liu
    PKU, Beijing, People’s Republic of China
  • S. Zhang
    JLab, Newport News, Virginia, USA
 
  This paper reports the study and demonstration of a new variable temporal shaping method capable of generating linearly polarized picosecond laser pulses with arbitrary predefined shapes, which are highly desired by various applications including low emittance high brightness electron bunch generation in photocathode guns. It is found that both high transmittance and high stability of the shaped pulses can be achieved simultaneously when crystals are set at specific phase delay through the fine control of the crystal temperature. Such variable temporal shaping technique may lead to new opportunities for many potential applications over a wide range of laser wavelengths, pulse repetition rates, time structures and power levels, etc. In addition, a new double-pass variable shaping method is also proposed and could significantly simplify the shaper structure and reduce the cost.
*liufangming@pku.edu.cn
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPGW044  
About • paper received ※ 13 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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