skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: LIFE EXPECTANCY STUDIES FOR LCLS-II PERMANENT MAGNET UNDULATORS

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1358675
Report Number(s):
SLAC-PUB-16983
DOE Contract Number:
AC02-76SF00515
Resource Type:
Conference
Resource Relation:
Conference: Presented at the 8th International Particle Accelerator Conference, 14-19 May 2017. Copenhagen, Denmark
Country of Publication:
United States
Language:
English
Subject:
ACCPHY, ACCSYS, XFEL

Citation Formats

Santana Leitner, M., Bruch, D., Field, C.R., Martinez-Galarce, D., McKee, R., Nuhn, H.-D., Rowen, M., Score, S.W., and /SLAC. LIFE EXPECTANCY STUDIES FOR LCLS-II PERMANENT MAGNET UNDULATORS. United States: N. p., 2017. Web.
Santana Leitner, M., Bruch, D., Field, C.R., Martinez-Galarce, D., McKee, R., Nuhn, H.-D., Rowen, M., Score, S.W., & /SLAC. LIFE EXPECTANCY STUDIES FOR LCLS-II PERMANENT MAGNET UNDULATORS. United States.
Santana Leitner, M., Bruch, D., Field, C.R., Martinez-Galarce, D., McKee, R., Nuhn, H.-D., Rowen, M., Score, S.W., and /SLAC. 2017. "LIFE EXPECTANCY STUDIES FOR LCLS-II PERMANENT MAGNET UNDULATORS". United States. doi:. https://www.osti.gov/servlets/purl/1358675.
@article{osti_1358675,
title = {LIFE EXPECTANCY STUDIES FOR LCLS-II PERMANENT MAGNET UNDULATORS},
author = {Santana Leitner, M. and Bruch, D. and Field, C.R. and Martinez-Galarce, D. and McKee, R. and Nuhn, H.-D. and Rowen, M. and Score, S.W. and /SLAC},
abstractNote = {},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2017,
month = 5
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • Pure Rare Earth Cobalt (REC) undulators and hybrid undulators, using both REC and steel, are described and compared with each other and with conventional and superconducting undulators.
  • The on-axis field of a small-gap undulator constricted out of pure permanent magnet (PM) blocks arranged in an alternating-dipole (i.e., 2 dipoles/period) array can be substantially varied by positioning monolithic permeable plates above and below the undulator jaws. This simple technique, which can be used to control the 1st harmonic energy in conventional synchrotron radiation (SR) or Free Electron Laser (FEL) applications requiring sub-octave tuning, can also be shown to suppress magnetic inhomogeneities that can contribute to the undulator`s on-axis field errors. If a standard 4 block/period Halbach undulator, composed of PM blocks with square cross sections, is rearranged intomore » an alternating-dipole array with the same period, the peak field that can be generated with superimposed image plates can substantially exceed that of the pure-PM Halbach array. This design technique, which can be viewed as intermediate between the {open_quotes}pure-PM{close_quotes} and standard {open_quotes}hybrid/PM{close_quotes} configurations, provides a potentially cost-effective method of enhancing the performance of small-gap, pure-PM insertion devices. In this paper we report on the analysis and recent characterization of pure-PM undulator structures with superimposed image plates, and discuss possible applications to FEL research.« less
  • In this paper we describe design, fabrication, and measurement aspects of a pure permanent magnet (PM) insertion device designed to operate as an FEL at a 1st harmonic energy of 300 eV and an electron energy of 7 GeV in the Self-Amplified Spontaneous Emission (SASE) regime.
  • 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