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

Title: Trajectory Stability Modeling And Tolerances in the LCLS

Abstract

To maintain stable performance of the Linac Coherent Light Source (LCLS) x-ray free-electron laser, one must control the electron trajectory stability through the undulator to a small fraction of the beam size. BPM-based feedback loops running at 120 Hz will be effective in controlling jitter at low frequencies less than a few Hz. On the other hand, linac and injector stability tolerances must be chosen to limit jitter at higher frequencies. In this paper we study possible sources of high frequency jitter, including: (1) steering coil current regulation; (2) quadrupole magnet transverse vibrations; (3) quadrupole current regulation with transverse misalignments; (4) charge variations coupled to jitter through transverse wakefields of misaligned RF structures; and (5) bunch length variations coupled through coherent synchrotron radiation in the bunch compressor chicanes. Based on this study, we set component tolerances and estimate expected trajectory stability in the LCLS.

Authors:
; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
902722
Report Number(s):
SLAC-PUB-12491
TRN: US0703084
DOE Contract Number:
AC02-76SF00515
Resource Type:
Conference
Resource Relation:
Conference: Prepared for European Particle Accelerator Conference (EPAC 06), Edinburgh, Scotland, 26-30 Jun 2006
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; LINEAR ACCELERATORS; FREE ELECTRON LASERS; LIGHT SOURCES; PERFORMANCE; COMPUTERIZED SIMULATION; STABILITY; ELECTRON BEAMS; BEAM DYNAMICS; Accelerators,ACCPHY

Citation Formats

Wu, J., Emma, P., and /SLAC. Trajectory Stability Modeling And Tolerances in the LCLS. United States: N. p., 2007. Web.
Wu, J., Emma, P., & /SLAC. Trajectory Stability Modeling And Tolerances in the LCLS. United States.
Wu, J., Emma, P., and /SLAC. Fri . "Trajectory Stability Modeling And Tolerances in the LCLS". United States. doi:. https://www.osti.gov/servlets/purl/902722.
@article{osti_902722,
title = {Trajectory Stability Modeling And Tolerances in the LCLS},
author = {Wu, J. and Emma, P. and /SLAC},
abstractNote = {To maintain stable performance of the Linac Coherent Light Source (LCLS) x-ray free-electron laser, one must control the electron trajectory stability through the undulator to a small fraction of the beam size. BPM-based feedback loops running at 120 Hz will be effective in controlling jitter at low frequencies less than a few Hz. On the other hand, linac and injector stability tolerances must be chosen to limit jitter at higher frequencies. In this paper we study possible sources of high frequency jitter, including: (1) steering coil current regulation; (2) quadrupole magnet transverse vibrations; (3) quadrupole current regulation with transverse misalignments; (4) charge variations coupled to jitter through transverse wakefields of misaligned RF structures; and (5) bunch length variations coupled through coherent synchrotron radiation in the bunch compressor chicanes. Based on this study, we set component tolerances and estimate expected trajectory stability in the LCLS.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Apr 27 00:00:00 EDT 2007},
month = {Fri Apr 27 00:00:00 EDT 2007}
}

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:
  • We have examined the influence of misalignments and magnet errors on the predicted performance of the Linac Coherent Light Source (LCLS). Due to the extremely large number of wiggler periods (> 10{sup 3}) and the small optical mode size (20 {mu}m), alignment and magnet tolerances will be quite demanding. These demands may increase if the wiggler is split into separate sections by the possible inclusion of diagnostic stations, dispersive sections, etc. We have attempted to quantify such tolerances using the numerical simulation code FRED-3D.
  • No abstract prepared.
  • The design of final focus systems for the next generation of linear colliders has evolved largely from the experience gained with the design and operation of the Stanford Linear Collider (SLC) and with the design of the Final Focus Test Beam (FFTB). The authors will compare the tolerances for two typical designs for a next-generation linear collider final focus system.
  • The design of final focus systems for the next generation of linear colliders has evolved largely from the experience gained with the design and operation of the Stanford Linear Collider (SLC) and with the design of the Final Focus Test Beam (FFTB). We will compare the tolerances for two typical designs for a next-generation linear collider final focus system. The chromaticity generated by strong focusing systems, like the final quadrupole doublet before the interaction point of a linear collider, can be canceled by the introduction of sextupoles in a dispersive region. These sextupoles must be inserted in pairs separated bymore » a -I transformation (Chromatic Correction Section) in order to cancel the strong geometric aberrations generated by sextupoles. Designs proposed for both the JLC or NLC final focus systems have two separate chromatic correction sections, one for each transverse plane separated by a ''{beta}-exchanger'' to manipulate the {beta}-function between the two CCS. The introduction of sextupoles and bending magnets gives rise to higher order aberrations (long sextupole and chrome-geometries) and radiation induced aberrations (chromaticity unbalance and ''Oide effect'') and one must optimize the lattice accordingly.« less