Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Investigation of Beam Alignment Monitor Technologies for the LCLS FEL Undulator

Journal Article · · AIP Conference Proceedings
OSTI ID:700426
 [1]; ;
  1. Stanford Synchrotron Radiation Laboratory

To maintain gain in the proposed 100 m long linac-driven Linac Coherent Light Source (LCLS) Free Electron Laser (FEL) undulator, the electron and photon beams must propagate colinearly to within {approximately}5 {mu}m rms over distances comparable to the 11.7 m FEL gain length in the 6 mm diameter undulator vacuum chamber. We have considered a variety of intercepting and non-intercepting position monitor technologies to establish and maintain this beam alignment. We present a summary discussion of the applicability and estimated performance of monitors detecting synchrotron radiation, transition and diffraction radiation, fluorescence, photoemission or bremsstrahlung from thin wires, Compton scattering from laser beams, and image currents from the electron beam. We conclude that: 1) non-intercepting rf cavity electron BPMs, together with a beam-based alignment system, are best suited for this application; and 2) insertable, intercepting wire monitors are valuable for rough alignment, for beam size measurements, and for simultaneous measurement of electron and photon beam position by detecting bremsstrahlung from electrons and diffracted x-rays from the photon beam. {copyright} {ital 1998 American Institute of Physics.}

Research Organization:
Stanford Linear Accelerator Center
DOE Contract Number:
AC03-76SF00515
OSTI ID:
700426
Report Number(s):
CONF-980573--
Journal Information:
AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 451; ISSN 0094-243X; ISSN APCPCS
Country of Publication:
United States
Language:
English