Applicability of ASST-A helium refrigeration system for JLab End Station Refrigerator

[摘要] The MOLLER experiment at Jefferson Lab (JLab) is a high power (5 kW) liquid hydrogen target scheduled to be operational in the 12 GeV-era. At present, cryogenic loads and targets at three of JLab's four experimental halls are supported by the End Station Refrigerator (ESR) - a CTI/Helix 1.5 kW 4.5 K refrigerator. It is not capable of supporting the high power target load and a capacity upgrade of the ESR cryogenic system is essential. The ASST-A helium refrigeration system is a 4 kW 4.5 K refrigerator. It was designed and used for the Superconducting Super Collider Lab (SSCL) magnet string test and later obtained by JLab after the cancellation of that project. The modified ASST-A refrigeration system, which will be called ESR-II along with a support flow from JLab's Central Helium Liquefier (CHL) is considered as an option for the End Station Refrigerator capacity upgrade. The applicability of this system for ESR-II under varying load conditions is investigated. The present paper outlines the findings of this process study.

[发布机构] Thomas Jefferson National Accelerator Facility, Newport News; VA; 23606, United States^1;Facility for Rare Isotope Beams (FRIB), Michigan State University (MSU), East Lansing; MI; 48824, United States^2

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Cryogenic system;Helium refrigeration systems;High-power target;Jefferson Lab;Liquid hydrogen target;Refrigeration system;Superconducting Super-Collider;Varying load conditions