Author: Hill, B.L.
Paper Title Page
THP080 A Low-Cost, High-Reliability Femtosecond Laser Timing System for LCLS 917
  • K. Gumerlock, J.C. Frisch, B.L. Hill, J. May, D.J. Nelson, S.R. Smith
    SLAC, Menlo Park, California, USA
  Funding: Work supported by DOE Contract DE-AC02-76-SF00515
LCLS has developed a low-cost, high-reliability radio-frequency-based locking system which provides phase locking with sub-25-femtosecond jitter for the injector and experiment laser systems. This system does not add significantly to the X-ray timing jitter from the accelerator RF distribution. The system uses heterodyne RF locking at 3808 MHz with an I/Q vector phase shifter and variable event receiver triggers to control the timing of the emission of the amplified laser pulse. Controls software provides full automation with a single process variable to control the laser timing over a 600 microsecond range with up to 4 femtosecond resolution, as well as online diagnostics and automatic error correction and recovery. The performance of this new locking system is sufficient for experiments with higher-precision timing needs that use an X-ray/optical cross-correlator to record relative photon arrival times.