SLAC, Menlo Park, California, USA
The LCLSII is a CW superconducting accelerator driven, hard and soft X-ray Free Electron Laser which is planned to be constructed at SLAC. It will operate with a variety of beam modes from single shot to approximately 1 MHz CW at bunch charges from 10pc to 300pC with average beam powers up to 1.2 MW. A variety of types of beam instrumentation will be used, including stripline and cavity BPMS, fluorescent and OTR based beam profile monitors, fast wire scanners and transverse deflection cavities. The beam diagnostics system is designed to allow tuning and continuous measurement of beam parameters, and to provide signals for fast beam feedbacks.
SLAC, Menlo Park, California, USA
LBNL, Berkeley, California, USA
Fermilab, Batavia, Illinois, USA
The LCLS-II is an FEL facility proposed in response to the July 2013 BESAC advisory committee, which recommended the construction of a new FEL light source with a high-repetition rate and a broad photon energy range from 0.2 keV to at least 5 keV. A new CW 4-GeV electron linac is being designed to meet this need, using a superconducting (SC) L-band (1.3 GHz) linear accelerator capable of operating with a continuous bunch repetition rate up to 1 MHz at ~16 MV/m. This new 700-m linac is to be built at SLAC in the existing tunnel, making use of existing facilities and providing two separate FELs, preserving the operation of the existing FEL, which can be fed from either the existing copper or the new SC linac. We briefly describe the acceleration, bunch compression, beam transport, beam switching, and electron beam diagnostics. The high-power and low-level RF, and cryogenic systems are described elsewhere.
SLAC, Menlo Park, California, USA
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.