Challenging EPICS Control System for the LCLS Project

Dr. Kukhee Kim

SLAC National Accelerator Laboratory
Affiliated Faculty of ISU Physics

Recently, SLAC constructed the world's first hard X-ray Free Electron Laser (XFEL) facility, Linac Coherent Light Source (LCLS). Its commissioning was finished  successfully, and the first user experiments were done in 2009. In the design phase, SLAC decided to re-use the last 1 km linac of the 3 km long Stanford Linear Collider (SLC) for the LCLS project. This idea worked successfully, but brought many new challenges. One of the challenges is its control system. SLAC has own home grown control system for the SLC linac, which is based on quite old fashion hardware such as CAMAC, and software as well. But this old system is still functioning for the linac timing and RF systems. Therefore for the LCLS project, SLAC decided to re-use the old SLC control system for the existing linac section due to limited man power and time. But SLAC determined to use the EPICS (Experimental Physics and Industrial Control System) to control new components of the LCLS project such as gun driving laser, gun, injector, bunch compressor, undulator, and the photon experimental beamlines. To use old SLC control system for the existing linac section and the EPICS control system for new components simultaneously and stably, it brought many challenging issues. During the talk, speaker will introduce the EPICS real-time control system and its advantages for the accelerator projects. Then, speaker will talk about several challenging issues to combine the new EPICS control system and the old SLC control system for the LCLS project. Finally, speaker will discuss on references to choose a proper control system for new or upgrade accelerator projects.