SLAC, Menlo Park, California, USA
The LCLS-II Project at SLAC National Accelerator is a major upgrade to the lab’s Free Electron Laser (FEL) facility adding a new injector and superconducting linac. In order to support this new linac, a vacuum pumping scheme was needed to isolate the liquid helium lines cooling the RF cavities inside the cryomodules from outside ambient heat as well as to exhaust any leaking helium gas. Carts were built with support for both roughing and high vacuum pumps and read back diagnostics. Additionally, a Programmable Logic Controller (PLC) was then configured to automate the pump down sequence and provide interlocks in the case of a vacuum burst. The design was made modular such that it can be manually relocated easily to other sections of the linac if needed depending on vacuum conditions.
* https://lcls.slac.stanford.edu/lcls-ii
SLAC, Menlo Park, California, USA
The LCLS-II Project at SLAC National Accelerator Laboratory has constructed a new superconducting accelerator which occupies the first kilometer of SLAC’s original 2-mile-long linear accelerator tunnel. The LCLS-II Vacuum System consists of a combination of particle free(PF) and non-particle free vacuum(non-PF) areas and multiple independent and interdependent systems, including the beamline vacuum, RF system vacuum, cryogenic system vacuum and support systems vacuum. The Vacuum Control System incorporates controls and monitoring of a variety of gauges, pumps, valves and Hiden RGAs. The design uses a Programmable Logic Controller (PLC) to perform valve interlocking functions to isolate bad vacuum areas. In PF areas, a voting scheme has been implemented for slow and fast shutter interlock logic to prevent spurious trips. Additional auxiliary control functions and high-level monitoring of vacuum components is reported to global control system via an Experimental Physics and Industrial Control System (EPICS) input output controller (IOC). This paper will discuss the design as well as the phased approach to installation and successful checkout of LCLS-II Vacuum Control System.
https://lcls.slac.stanford.edu/lcls-ii