Cryogenic refrigeration system and refrigeration method therefor

摘要

A plurality of cryopumps are installed in each of a plurality of neutral beam injection apparatuses disposed around a nuclear fusion apparatus. The cryopanels of each of the cryopumps are refrigerated by a small helium refrigerating machine. Since the cryopanels are refrigerated from room temperature with cold liquid nitrogen used for refrigerating a heat shield plate, then a small helium refrigerating machine and finally cold liquid helium itself, various valves and a small helium refrigerating machine are disposed. This permits refrigeration of a plurality of cryopumps within a short time, thereby saving the power consumption and improving the operating reliability of a refrigeration system.