Operational experience from LCLS-II cryomodule testing

[摘要] This paper describes the initial operational experience gained from testing Linac Coherent Light Source II (LCLS-II) cryomodules at Fermilab's Cryomodule Test Facility (CMTF). Strategies for a controlled slow cooldown to 100 K and a fast cooldown past the niobium superconducting transition temperature of 9.2 K will be described. The test stand for the cryomodules at CMTF is sloped to match gradient in the LCLS-II tunnel at Stanford Linear Accelerator (SLAC) laboratory, which adds an additional challenge to stable liquid level control. Control valve regulation, Superconducting Radio-Frequency (SRF) power compensation, and other methods of stabilizing liquid level and pressure in the cryomodule 2.0 K SRF cavity circuit will be discussed. Several different pumping configurations using cold compressors and warm vacuum pumps have been used on the cryomodule 2.0 K return line and the associated results will be described.

[发布机构] Fermi National Accelerator Laboratory, MS 347, P.O. Box 500, Batavia; IL; 60510, United States^1

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Cold compressors;Control valves;Linac Coherent Light Source;Operational experience;Power compensation;Pumping configurations;Stable liquids;Superconducting radio frequency