Keyword: undulator
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MOPHA006 SwissFEL Undulator Control System controls, FEL, PLC, MMI 197
 
  • A.D. Alarcon
    PSI, Villigen PSI, Switzerland
 
  SwissFEL has successfully commissioned the Aramis beamline, hard x-rays (2 - 12.4 KeV), and the Athos line, soft x-rays (200 eV to 2 keV), will start commissioning in 2020. The Aramis undulator line is currently composed of 13 variable-gap in-vacuum undulators. The Athos line will be made of 16 APPLE II type undulators (Advanced Planar Polarized Light Emitter). Both beamlines have each undulator segment on a 5D mover system; they both also have phase shifters and movable quadrupole tables in between segments. PLCs and DeltaTau motor controllers are used to control motion, for I/O interface, and interlocks. EPICS IOCs communicate with the controllers and provide additional logic and some high level functionality. Further higher level functions are provided through Python scripts and other high level languages.  
poster icon Poster MOPHA006 [1.265 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-MOPHA006  
About • paper received ※ 30 September 2019       paper accepted ※ 08 October 2019       issue date ※ 30 August 2020  
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MOPHA069 Automation of the Undulator Middle Plane Alignment Relative to the Electron Beam Position Using the K-Monochromator electron, FEL, controls, photon 375
 
  • S. Karabekyan, S. Abeghyan, W. Freund
    EuXFEL, Schenefeld, Germany
  • L. Fröhlich
    DESY, Hamburg, Germany
 
  The correct K value of an undulator is an important parameter to achieve lasing conditions at free electron lasers. The accuracy of the installation of the undulator in the tunnel is limited by the accuracy of the instruments used in surveying. Moreover, the position of the electron beam also varies depending on its alignment. Another source of misalignment is ground movement and the resulting change in the position of the tunnel. All this can lead to misalignment of the electron beam position relative to the center of the undulator gap up to several hundred microns. That, in turn, will lead to a deviation of the ΔK/K parameter several times higher than the tolerance requirement. An automated method of aligning the middle plane of the undulator, using a K-monochromator, was developed and used at European XFEL. Details of the method are described in this article. The results of the K value measurements are discussed.  
poster icon Poster MOPHA069 [0.780 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-MOPHA069  
About • paper received ※ 30 September 2019       paper accepted ※ 10 October 2019       issue date ※ 30 August 2020  
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TUCPL04 A Model-Based Simulator for the LCLS Accelerator EPICS, software, electron, operation 773
 
  • M.L. Gibbs, W.S. Colocho, A. Osman, J. Shtalenkova
    SLAC, Menlo Park, California, USA
 
  The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory is currently undergoing a major upgrade. In order to facilitate the development of new software that will be needed to operate the upgraded machine, a simulator has been developed to simulate the LCLS electron beam and the accelerator devices that measure and manipulate it. The simulator is comprised of several small "services" that simulate different types of devices, and provide an EPICS interface identical to the real control system. All of the services communicate with a central beam line model to change accelerator parameters and retrieve information about the simulated beam.  
slides icon Slides TUCPL04 [5.784 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-TUCPL04  
About • paper received ※ 01 October 2019       paper accepted ※ 09 October 2019       issue date ※ 30 August 2020  
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WECPL03 Implementation of the Motion Control System for LCLS-II Undulators controls, vacuum, EPICS, hardware 915
 
  • M.A. Montironi, C.J. Andrews, H. Bassan, K.R. Lauer, Yu.I. Levashov, H.-D. Nuhn, Z.R. Wolf
    SLAC, Menlo Park, California, USA
  • Ž. Oven
    Cosylab, Ljubljana, Slovenia
 
  As part of the LCLS upgrade called LCLS-II, two new undulator lines were introduced: a soft X-Ray line (SXR) and a hard H-Ray line (HXR). Serving distinct purposes, the two undulator lines employ different undulator designs. The SXR line is composed of 21 vertical gap, horizontally polarized undulators while the HXR line is composed of 32 undulator segments designed to operate on the horizontal axis and to produce a vertically polarized beam. The HXR undulators will replace the LCLS ones and thus the control system was designed with the main goal of maximizing the re-utilization of existing hardware and software. For this purpose, the motion control system based on RTEMS running on VME with Animatics SmartMotors was developed as an upgrade of the LCLS design and the cam-based undulator girder positioning system has been reused. The all new SXR undulators employ a new control system design based on Aerotech motion controllers and EPICS soft IOCs (input-output controllers). This paper describes how the most challenging motion control requirements were implemented focusing on motion synchronization, K-value to gap transformation, cams kinematics and calibration, and user interaction.  
slides icon Slides WECPL03 [0.625 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-WECPL03  
About • paper received ※ 29 September 2019       paper accepted ※ 09 October 2019       issue date ※ 30 August 2020  
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WEPHA099 XLEAP-II Motion Control controls, wiggler, feedback, electron 1325
 
  • M.A. Montironi, H. Bassan, M.A. Carrasco, E.M. Kraft, A. Marinelli
    SLAC, Menlo Park, California, USA
 
  The XLEAP project was conceived with the main scope of extending the generation of ultrashort pulses at LCLS to the sub-femtosecond (sub-fs) regime. As the project produced the expected results, an upgrade called XLEAP-II is being designed to provide the same functionality to LCLS-II. The XLEAP project utilized one variable gap wiggler to produce sub-fs X-ray pulses. The upgrade will involve four additional wigglers in the form of repurposed LCLS fixed gap undulators mounted on translation stages. This paper describes the design of the hardware and software architecture utilized in the motion control system of the wigglers. First it discusses how the variable gap wiggler was upgraded to be controlled by an Aerotech Ensemble motion controller through an EPICS Soft IOC (input-output controller). Then the motion control strategy for the additional four wigglers, also based around Aerotech controllers driving servomotors, is presented. Lessons learned from operating the wiggler and undulators during LCLS operation are discussed and utilized as a base upon which the upgraded motion control system is designed and built. Novel challenges are also identified and mitigations are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-WEPHA099  
About • paper received ※ 01 October 2019       paper accepted ※ 10 October 2019       issue date ※ 30 August 2020  
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WEPHA165 Upgrade of the European XFEL Phase Shifters operation, FEL, controls, software 1473
 
  • M. Yakopov, S. Abeghyan, M. Bagha-Shanjani, S. Karabekyan, J. Pflüger, F. Preisskorn
    EuXFEL, Schenefeld, Germany
  • G. Chen
    CAEP, Sichuan, People’s Republic of China
 
  To eliminate the impact of radiation shower on the incremental encoder readout and provide a better dynamic movement the upgrade of all 88 phase shifters of the European XFEL have been successfully done without interruption of the operation schedule. The implementation steps, as well as the results of the hardware and software tests made in the laboratory, are presented. The sensitivity of the Renishaw RGH22O15D00A encoder to the radiation shower was measured in the SASE3 undulator system, and the results are presented.  
poster icon Poster WEPHA165 [2.315 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-WEPHA165  
About • paper received ※ 01 October 2019       paper accepted ※ 18 October 2019       issue date ※ 30 August 2020  
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THCPR04 The European XFEL Beam Loss Monitor System FEL, electron, high-voltage, controls 1630
 
  • T. Wamsat, T. Lensch
    DESY, Hamburg, Germany
 
  The European XFEL MTCA based Beam Loss Monitor (BLM) System is composed of about 470 BLMs, which are part of the Machine Protection System (MPS). The BLMs detect losses of the electron beam, in order to protect accelerator components from damage and excessive activation, in particular the undulators, since they are made of permanent magnets. Also each cold accelerating module is equipped with a BLM to measure the sudden onset of field emission (dark current) in cavities. In addition some BLMs are used as detectors for wire- scanners. Further firmware and server developments related to alarm generation and handling are ongoing. The BLM systems structure, the current status and the different possibilities to trigger alarms which stop the electron beam will be presented.  
slides icon Slides THCPR04 [7.156 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ICALEPCS2019-THCPR04  
About • paper received ※ 02 October 2019       paper accepted ※ 09 October 2019       issue date ※ 30 August 2020  
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