Abstract:The LCLS hard x-ray Free Electron Laser at SLAC reported first lasing in April of 2009. Since then two successful user runs have been completed at the two soft x-ray stations. The first hard x-ray station has started commissioning in July of 2010. Beam diagnostics play an essential role for tuning the machine and delivering the requested beam properties to the users. An overview of the LCLS photon diagnostics will be presented including some selected commissioning results. Plans for future improvements and upgrades will be briefly discussed.
The first phase of the ISAC II project consists of the acceleration of radioactive ions by 20 superconducting DTL's with a total effective voltage of up to 20 MV. Each of these quarter-wave cavities will be powered at a frequency of 106.08 MHz to a maximum field gradient of 6 MV/m. A test area was built to clean and test each cavity before installation. With unloaded cavity Q's of ~10 9 , the RF control system of these superconducting cavities is based on self-excited feedback loop, with the self-excited frequency stabilized by an internal analogue Phase-Locked Loop, capable of operating in both CW and pulse mode. A digital phase/frequency detector and a quadrature combiner are used to provide phase locking to an external frequency reference. The demodulated amplitude, phase and frequency are feedback regulated with digital signal processors. This paper describes the RF control system and the experience in operating this system with a prototype cavity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.