MC2: Photon Sources and Electron Accelerators
T15 Undulators and Wigglers
Paper Title Page
TUPGW017 Superconducting Undulator Coils with Period Length Doubling 1426
 
  • S. Casalbuoni, N. Glamann, A.W. Grau, T. Holubek, D. Saez de Jauregui
    KIT, Eggenstein-Leopoldshafen, Germany
 
  Funding: Work supported by the German government in the BMBF-project Superconducting ’Insertion Device Technologies for Ultra-Low-Emittance Light Sources’ (05K12CK1)
Only since few years it has been demonstrated experimentally that NbTi based superconducting undulators (SCUs) have a higher peak field on axis for the same gap and period length in operation with electron beam with respect to permanent magnet undulators (even the ones in vacuum and cooled to cryogenic temperatures). Another advantage of NbTi based SCUs with respect to permanent magnet devices is radiation hardness, widely demonstrated for NbTi magnets, which is and will become an increasingly important issue with the small gaps in the newest machines as round beam storage rings and FELs. Moreover, SCU technology allows switching of the period length by changing the current direction in one of separately powered subset of winding packages of the superconducting coils. This feature further broadens the energy range of the emitted photons, required by the different beamlines. To this end 0.5 m long superconducting undulator coils with switchable period length between 17 mm and 34 mm have been developed. In this contribution we describe the design and report on the quench tests, as well as on the magnetic field measurements.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW017  
About • paper received ※ 25 April 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 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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TUPGW098 Fabrication & Cold Tests of a Millimeter-Period RF Undulator 1643
 
  • F. Toufexis, B. J. Angier, D. Gamzina, S.G. Tantawi
    SLAC, Menlo Park, California, USA
 
  Funding: This project was funded by U.S. Department of Energy under Contract No. DE-AC02-76SF00515, and the National Science Foundation under Contract No. PHY-1415437.
To reduce the linac energy required for an FEL radiating at a given wavelength, and hence its size, a smaller undulator period with sufficient field strength is needed. Previous work from our group successfully demonstrated a microwave undulator at 11.424GHz, using a corrugated cylindrical waveguide operating at the HE11 modes. We have designed a mm-wave undulator cavity at 91.392GHz* with an equivalent undulator period of 1.75 mm. This undulator requires 1.4 MW for sub microsecond pulses for an equivalent K value of 0.1. In this work we present the mechanical design and fabrication of this 91.392 GHz RF Undulator, as well as preliminary cold test data.
* F. Toufexis and S.G. Tantawi, "A 1.75-mm Period RF-Driven Undulator", Proceedings of IPAC17.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPGW098  
About • paper received ※ 10 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPRB002 The Conceptual Design of a 36 GHz RF Undulator 1676
 
  • D. Zhu
    ASCo, Clayton, Victoria, Australia
  • A.W. Cross, L. Zhang
    USTRAT/SUPA, Glasgow, United Kingdom
  • Y.E. Tan
    AS - ANSTO, Clayton, Australia
 
  The CompactLight project supported by European H2020 is to design a hard X-ray FEL facility beyond today’s state of the art. The project integrates photo injector, X-band acceleration and innovative compact short-period undulators together to make the machine more compact. RF undulator has an extraordinary advantage of working at very short undulator period. A conceptual design for a RF undulator at 36 GHz using a corrugated cylindrical waveguide operating in the HE11 mode is presented in this paper. Based on beam dynamics simulation and photon beam radiation simulations, the possibility of RF undulator to be used in CompactLight project is evaluated.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB002  
About • paper received ※ 15 May 2019       paper accepted ※ 23 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 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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TUPRB004 Magnetic Measurements of Insertion Devices Using the Vibrating Wire Technique 1683
 
  • C.K. Baribeau, D. Bertwistle, E. J. Ericson, J.T. Gilbert, T.M. Pedersen
    CLS, Saskatoon, Saskatchewan, Canada
 
  The commissioning of new in-vacuum insertion devices (ID) at the Canadian Light Source has motivated the assembly and development of a vibrating wire system. The advantage of the technique is that it is a sensitive magnetic measurement instrument at relatively low cost. Moreover, most hall probe systems require transverse access, which is often not available for in-vacuum or Delta-like devices. It is comparatively simple to string a taut wire through the gap of an in-vacuum ID. We describe the experimental challenges in mapping the field of an 80 mm period in-vacuum wiggler, IVW80, using the vibrating wire technique, and compare results against simulation and data obtained from Hall probe measurements.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB004  
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 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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TUPRB015 Cryogenic, in-Vacuum Magnetic Measurement Setup for Superconducting Undulators 1709
 
  • A.W. Grau, S. Casalbuoni, N. Glamann, D. Saez de Jauregui
    KIT, Eggenstein-Leopoldshafen, Germany
 
  The magnetic field quality has a strong impact on the performance of insertion devices (IDs) when installed in synchrotron light sources. Superconducting IDs have the advantage to produce a higher magnetic peak field for a given gap and period length than IDs assembled with permanent magnets. Before installation of a superconducting ID in a synchrotron light source it is of fundamental importance to characterize the magnetic properties by accurate field and field integral measurements. We follow this aim within our R&D program for superconducting undulators (SCUs). In this contribution, we describe the equipment and the challenges of a cryogenic, in vacuum measurement setup to perform magnetic measurements of the local field, the field integrals and the multipole components of in vacuum SCUs assembled in the final cryostat.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB015  
About • paper received ※ 29 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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TUPRB021 Undulator Radiation Dose Caused by Synchrotron Radiation at the European XFEL 1724
 
  • S. Liu
    DESY, Hamburg, Germany
  • Y. Li, F. Wolff-Fabris
    EuXFEL, Hamburg, Germany
 
  Radiation damage of the undulators is a big concern for the light sources. At the European XFEL (EuXFEL), dosimeters based on on-line Radfets are used for the un-dulator radiation dose measurements. However, since the Radfets are not only sensitive to the electrons and neu-trons but also to the photons, it can capture the synchro-tron radiation (SR) generated in the undulators, which is not considered to be the main source for undulator radia-tion damage. Therefore, it is important to estimate the contribution of synchrotron radiation to the radiation doses measured by the Radfets. For this purpose, we have first calculated the synchrotron radiation profile using SPECTRA, and then put the profile into the tracking code BDSIM to track it through the whole undulator beam line. The radiation doses from SR have been simulated and compared with the measured values. The differences in the radiation doses measured by the Radfets before and after Pb shielding will also be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB021  
About • paper received ※ 30 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPRB022 Triple Period Undulator 1728
 
  • A. Meseck, J. Bahrdt, W. Frentrup, M. Huck, C. Kuhn, C. Rethfeldt, M. Scheer
    HZB, Berlin, Germany
  • E.C.M. Rial
    DLS, Oxfordshire, United Kingdom
 
  Insertion devices are one of the key components of modern synchrotron radiation facilities. They allow for generation of radiation with superior properties enabling experiments in a variety of disciplines, such as chemistry, biology, crystallography and physics to name a few. For future cutting edge experiments in soft and tender x-rays users require high flux and variable Polarization over a wide photon energy range independent of other desired properties like variable pulse length, variable timing or Fourier transform limited pulses. In this paper, we propose a novel ID-structure, called Triple Period Undulator (TPU), which allow us to deliver a wide energy range from a few ten eV to a few keV at the same beamline with high flux and variable Polarization. The TPU are particularly interesting in context of BESSY III, the successor facility of BESSY II.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB022  
About • paper received ※ 15 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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TUPRB033 Fixed-gap Undulators for Elettra and FERMI 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 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 1769
SUSPFO043   use link to see paper's listing under its alternate paper code  
 
  • 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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TUPRB052 The Mini-Period Permanent Magnet Staggered Undulator for Compact X-Ray Free Electron Laser 1797
 
  • L.G. Yan, D.R. Deng, J. Wang
    CAEP/IAE, Mianyang, Sichuan, People’s Republic of China
 
  Funding: Work supported by National Natural Science Foundation of China under grant of 11505174, 11505173 and 11605190.
Miniaturization of X-ray free electron laser requires reduction of undulator period length. In this proceeding, a mini-period permanent magnet staggered undulator was proposed, which is free of superconducting solenoid and thus has advantages of easy-manufacture and low-cost. After optimization, it can generate periodic field of peak field 0.71 T with period length 10 mm and pole gap 2 mm, which has been verified on a prototype. Combined with X-band linac, the length of 1 nm XFEL facility using the permanent magnet staggered undulator can be confined within 44 m.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB052  
About • paper received ※ 30 April 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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TUPRB055 First Results of the IVU16 Prototype Undulator Measurements 1808
 
  • C. Yu, Y.Z. He, X. Hu, Z. Jiang, M.F. Qian, Y.M. Wen, S. Xiang, L. Yin, J.D. Zhang, W. Zhang, Q.G. Zhou
    SINAP, Shanghai, People’s Republic of China
  • H.X. Deng, B. Liu, D. Wang
    SARI-CAS, Pudong, Shanghai, People’s Republic of China
  • H.F. Wang, Z.T. Zhao
    SSRF, Shanghai, People’s Republic of China
 
  The Shanghai Synchrotron Radiation Facility (SSRF) has developed a 16 mm period length, 4 mm gap, in-vacuum undulator (IVU) that is planned to be installed and tested in the 1.5 GeV SXFEL-SBP beam line. This paper will describe the main parameters of the undulator and the key design choices that have been made. The first undulator prototype was assembled and magnetically tested. First measurements with vacuum chamber will be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB055  
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 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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TUPRB094 New Superconducting Undulator Magnetic Measurement System for the Advanced Photon Source Upgrade 1881
 
  • M. Kasa, E.R. Anliker, Y. Ivanyushenkov, Y. Shiroyanagi
    ANL, Argonne, Illinois, USA
 
  Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Magnetic measurements of existing superconducting undulators (SCUs) are performed under normal operating conditions after final assembly into the cryostat and before installation on the Advanced Photon Source (APS) storage ring. The SCU cryostat for the APS upgrade has been scaled in length from the current cryostat and will contain two SCUs. While some aspects of the current measurement system are desirable to retain, such as a room temperature measurement bore, scaling the current measurement techniques to the length required for the APS upgrade cryostat is not feasible. To address these challenges a unique system has been developed at the APS to allow measurements of the two SCU magnets in the long cryostat. The measurement system developed allows the magnets to be operated under normal operating conditions while maintaining the measurement equipment at room temperature and atmospheric pressure.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB094  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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TUPRB095 Superconducting Undulators for the Advanced Photon Source Upgrade 1884
 
  • M. Kasa, E.R. Anliker, J.D. Fuerst, Q.B. Hasse, Y. Ivanyushenkov, I. Kesgin, Y. Shiroyanagi, E. Trakhtenberg
    ANL, Argonne, Illinois, USA
 
  Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
The magnetic devices group at the Advanced Photon Source (APS) is in the process of designing and developing superconducting undulators (SCUs) for the APS upgrade. While similar in some aspects to previous SCU systems currently in operation at the existing APS, the new SCU systems will include two undulators installed in one cryostat which occupies an entire straight section of the storage ring. Straight sections containing planar undulators will either be configured as ’in-line’, where the two undulators behave as one source, or canted, where the two undulators are operated independently. Also under development is a superconducting arbitrary polarizing emitter (SCAPE) which can produce planar, elliptical, and helical undulator fields.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB095  
About • paper received ※ 14 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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TUPRB101 Damping Trapped Modes in an in-Vacuum Undulator at a Synchrotron Radiation Light Source 1895
TUPRB098   use link to see paper's listing under its alternate paper code  
 
  • K. Tian, Z. Li, A. Ringwall, J.J. Sebek
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by US Department of Energy Contract DE-AC03-76SF00515.
In this paper, we report the efforts in solving the problem of coupled-bunch instabilities caused by an in-vacuum undulator in the SPEAR3 storage ring. After exploring several approaches to reduce the strength of the trapped modes, we found that ferrite dampers were the most effective and simplest way for mode damping in our SPEAR3 in-vacuum undulator. The results of the first RF cold measurement on an in-vacuum undulator equipped with these ferrite dampers agree well with numerical simulations.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB101  
About • paper received ※ 13 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
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TUPRB102 Numerical Study of the Delta II Polarizing Undulator for LCLS II 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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WEPTS102 Helical Wiggler Model for Fast Tracking 3356
 
  • W.F. Bergan, V. Khachatryan, D. L. Rubin
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: NSF-1734189 DGE-1650441
In order to test the process of Optical Stochastic Cooling (OSC) at the Cornell Electron Storage Ring (CESR), we plan to use helical wigglers as both the pickup and kicker, since the required radiation wavelength of 800nm can be achieved with lower magnetic field strength in helical as compared to planar wigglers. In order to simulate the lattice with such wigglers, it is useful to be able to model the effect of the wiggler on the optics without resorting to direct tracking, which is time-consuming and so ill-suited for the repeated evaluations necessary in running an optimizer. We generate a Taylor map to third order for this element using analytic field expressions, enabling easy determination of the effects of such an element on linear and nonlinear optics. This model is compared with the results of direct tracking and shows good agreement.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPTS102  
About • paper received ※ 14 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
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THYPLM1 Development of the Vertically Polarizing Hard X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) Project 3408
 
  • M. Leitner, D. Arbelaez, J.N. Corlett, A.J. DeMello, L. Garcia Fajardo, D. Leitner, S. Marks, K.A. McCombs, T. Miller, D.V. Munson, J. Niu, K.L. Ray, D.A. Sadlier, D. Schlueter, E.J. Wallén
    LBNL, Berkeley, California, USA
  • H. Bassan, D.E. Bruch, D.S. Martinez-Galarce, H.-D. Nuhn, M. Rowen, Z.R. Wolf
    SLAC, Menlo Park, California, USA
  • C.W. Chen
    NSRRC, Hsinchu, Taiwan
 
  Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Linear Coherent Light Source II (LCLS-II) is a free electron laser facility currently in its final construction stage at Stanford Linear Accelerator Center. The project includes two variable-gap, hybrid-permanent-magnet undulator lines: A soft x-ray undulator line with 21 undulator segments optimized for a photon energy range from 0.2 keV to 1.3 keV and a hard x-ray undulator line with 32 undulator segments designed for a photon energy range from 1.0 keV to 25.0 keV. This paper focuses on the design, development, and performance of the hard x-ray undulator line which utilizes uniquely-developed, vertically-polarizing undulators. To fully compensate the magnetic force throughout the entire gap range these devices incorporate non-linear spring systems which permit the construction of relatively compact undulators. However, significant magnetic field repeatability challenges have been encountered during prototyping of this novel design. The paper describes the innovative design improvements that were implemented which lead to reaching the LCLS-II required performance. These final design solutions can also be advantageous improving the operation of any future undulator design.
 
slides icon Slides THYPLM1 [28.498 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THYPLM1  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
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THPTS073 Radiation Damage to Undulator Electronics at an Electron Accelerator 4285
 
  • T.Y. Chung, C.-H. Chang, A.Y. Chen, Y.W. Chen, J.C. Huang, J.C. Jan
    NSRRC, Hsinchu, Taiwan
 
  Experience gained from commissioning and operation of three elliptical polarization undulators (EPU) at the TPS taught us that undulator driving systems can behave erratically following a beam dump or loss. In this work, we discuss possible harmful radiation sources in a storage ring and analyse the effect of lack of electronic component radiation resistance in the system. According to measurements of spatial radiation distribution at the TPS, we propose solutions and an improved design for Phase-II EPUs.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPTS073  
About • paper received ※ 19 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)