Commissioning and Operation of the CEBAF End Station Refrigeration System

Abstract

The CEBAF End Station Helium Refrigerator (ESR) System 1 provides refrigeration at 80 K, 20 K and 4.5 K to three End Station experimental halls. The facility consists of a two stage helium screw compressor system, 4.5 K refrigerator, cryogen distribution valve box, and transfer lines to the individual experimental halls. The 4.5 K cold box and compressors were originally part of the ESCAR 1500 W, 4 K refrigeration system at Lawrence Berkeley Laboratory which was first commissioned in 1977. The compressors, 4.5 K cold box, and control system design were modified to adapt the plant for the requirements of the CEBAF experimental halls. Additional subsystems of cryogen distribution, transfer lines 2, warm gas management, and computer control interface were added. This paper describes the major plant subsystems, modifications, operational experiences and performance.KeywordsLawrence Berkeley LaboratoryExperimental HallCryogenic TargetTurbine ExpanderCompressor SuctionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.