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Title: Status of the LCLS-II undulators

Abstract

The new free electron laser facility Linear Coherent Light Source II (LCLS-II) under construction at SLAC National Accelerator Laboratory will use planar variable gap undulators of hybrid type for the production of free electron laser (FEL) radiation. The LCLS-II will include two FELs with two separate rows of undulators to generate soft and hard x-rays. The soft x-rays will be produced by undulators with 39 mm period length (SXR) and the hard x-rays will be produced by undulators with 26 mm period length (HXR). Both the SXR and the HXR undulators are 3.4 m long and they use a common support structure and frame. In total 21 SXR and 32 HXR undulators will be produced by Lawrence Berkeley National Laboratory in collaboration with SLAC National Accelerator Laboratory. A full-scale prototype with 32 mm period length, called HXU, has been assembled at Lawrence Berkeley National Laboratory (LBNL). The present status of the design, prototyping, and pre-series production of the SXR and HXR undulators are presented in this paper together with the first results from measurements on the full scale HXU prototype.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1]; ;  [2]
  1. Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)
  2. SLAC National Accelerator Laboratory 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)
Publication Date:
OSTI Identifier:
22608319
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1741; Journal Issue: 1; Conference: SRI2015: 12. international conference on synchrotron radiation instrumentation, New York, NY (United States), 6-10 Jul 2015; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ELECTRONS; FERMILAB ACCELERATOR; FREE ELECTRON LASERS; HARD X RADIATION; LAWRENCE BERKELEY LABORATORY; SOFT X RADIATION; STANFORD LINEAR ACCELERATOR CENTER; WIGGLER MAGNETS

Citation Formats

Wallén, E., E-mail: ejwallen@lbl.gov, Arbelaez, D., Brown, A., Dougherty, J., Corlett, J., DeMello, A., Hanzel, K., Jung, J.-Y., Leitner, M., Madur, A., McCombs, K., Marks, S., Munson, D., Plate, D., Pucci, J., Ray, K., Schlueter, R., Mateo, E. San, D’Ewart, M., and Rowen, M. Status of the LCLS-II undulators. United States: N. p., 2016. Web. doi:10.1063/1.4952804.
Wallén, E., E-mail: ejwallen@lbl.gov, Arbelaez, D., Brown, A., Dougherty, J., Corlett, J., DeMello, A., Hanzel, K., Jung, J.-Y., Leitner, M., Madur, A., McCombs, K., Marks, S., Munson, D., Plate, D., Pucci, J., Ray, K., Schlueter, R., Mateo, E. San, D’Ewart, M., & Rowen, M. Status of the LCLS-II undulators. United States. doi:10.1063/1.4952804.
Wallén, E., E-mail: ejwallen@lbl.gov, Arbelaez, D., Brown, A., Dougherty, J., Corlett, J., DeMello, A., Hanzel, K., Jung, J.-Y., Leitner, M., Madur, A., McCombs, K., Marks, S., Munson, D., Plate, D., Pucci, J., Ray, K., Schlueter, R., Mateo, E. San, D’Ewart, M., and Rowen, M. 2016. "Status of the LCLS-II undulators". United States. doi:10.1063/1.4952804.
@article{osti_22608319,
title = {Status of the LCLS-II undulators},
author = {Wallén, E., E-mail: ejwallen@lbl.gov and Arbelaez, D. and Brown, A. and Dougherty, J. and Corlett, J. and DeMello, A. and Hanzel, K. and Jung, J.-Y. and Leitner, M. and Madur, A. and McCombs, K. and Marks, S. and Munson, D. and Plate, D. and Pucci, J. and Ray, K. and Schlueter, R. and Mateo, E. San and D’Ewart, M. and Rowen, M.},
abstractNote = {The new free electron laser facility Linear Coherent Light Source II (LCLS-II) under construction at SLAC National Accelerator Laboratory will use planar variable gap undulators of hybrid type for the production of free electron laser (FEL) radiation. The LCLS-II will include two FELs with two separate rows of undulators to generate soft and hard x-rays. The soft x-rays will be produced by undulators with 39 mm period length (SXR) and the hard x-rays will be produced by undulators with 26 mm period length (HXR). Both the SXR and the HXR undulators are 3.4 m long and they use a common support structure and frame. In total 21 SXR and 32 HXR undulators will be produced by Lawrence Berkeley National Laboratory in collaboration with SLAC National Accelerator Laboratory. A full-scale prototype with 32 mm period length, called HXU, has been assembled at Lawrence Berkeley National Laboratory (LBNL). The present status of the design, prototyping, and pre-series production of the SXR and HXR undulators are presented in this paper together with the first results from measurements on the full scale HXU prototype.},
doi = {10.1063/1.4952804},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1741,
place = {United States},
year = 2016,
month = 7
}
  • Utilization of superconducting permanent magnets is now under investigation at SPring-8 for future development of synchrotron radiation sources, and several concepts has been reported so far. In one of them, ring-shaped bulk superconductors (ring SCs) will be used for enhancement of the undulator field strength. In the previous work, it was reported that the mechanical property of the ring SCs were so poor that the magnetic performance degraded during experiments. In this work, several methods are proposed to enhance the mechanical property of the ring SCs and results of experiments performed to investigate the effects of them are reported. Resinmore » impregnation with a pole piece inserted into the ring SCs is found to be effective.« less
  • The collaboration for the Linac Coherent Light Source (LCLS) under the leadership of the Stanford Linear Accelerator Center (SLAC) has been preparing the design report since the middle of 1996 to be completed before the end of calendar year 1997. The work on the report greatly improved the understanding of problems and helped to develop solutions for many of them. The present article will focus on one particular aspect, the simulation of the FEL process, itself. {copyright} {ital 1997 American Institute of Physics.}
  • The collaboration for the Linac Coherent Light Source (LCLS) under the leadership of the Stanford Linear Accelerator Center (SLAC) has been preparing the design report since the middle of 1996 to be completed before the end of calendar year 1997. The work on the report greatly improved the understanding of problems and helped to develop solutions for many of them. The present article will focus on one particular aspect, the simulation of the FEL process, itself.
  • The Linac Coherent Light Source (LCLS) is an X-ray free-electron laser (FEL) project based on the SLAC linac [1]. With its nominal set of electron beam, focusing and undulator parameters, it is designed to achieve SASE saturation at an undulator length of about 100 m with an average power of 10 GW. In order to keep the electron beam focused in the undulators, a FODO lattice is integrated along the entire length of the undulators. Nominally, the quadrupole strengths are chosen to produce nearly constant betafunction and beam size along the undulator, optimized for the FEL interaction in the exponentialmore » growth regime. Since these quadrupoles are electromagnetic, it is possible to adjust the individual quadrupole strength to vary the betafunction and the beam size along the undulator, tailoring the FEL interaction in the start-up and the saturation regimes. In this paper, we present simulation studies of the tapered betafunction in the LCLS undulator and discuss the generated X-ray properties.« less
  • The x-ray FEL process puts very tight tolerances on the straightness of the electron beam trajectory (2 {micro}m rms) through the LCLS undulator system. Tight but less stringent tolerances of 80 {micro}m rms vertical and 140 {micro}m rms horizontally are to be met for the placement of the individual undulator segments with respect to the beam axis. The tolerances for electron beam straightness can only be met through beam-based alignment (BBA) based on electron energy variations. Conventional alignment will set the start conditions for BBA. Precision-fiducialization of components mounted on remotely adjustable girders and the use of beam-finder wires (BFW)more » will satisfy placement tolerances. Girder movement due to ground motion and temperature changes will be monitored continuously by an alignment monitoring system (ADS) and remotely corrected. This stabilization of components as well as the monitoring and correction of the electron beam trajectory based on BPMs and correctors will increase the time between BBA applications. Undulator segments will be periodically removed from the undulator Hall and measured to monitor radiation damage and other effects that might degrade undulator tuning.« less