超低振動パルス管冷凍装置

—冷凍能力と振動—

抄録

This report describes the development of low vibration cooling systems with pulse tube (PT) cryocoolers. Generally, PT cryocoolers have the merit of lower vibration than GM cryocoolers. However, the cooling systems for a cryogenic laser interferometor observatory (CLIO), which is a gravitational wave detector, require sufficiently lower operational vibration than that of a commercial PT cryocooler. The required specification for vibration amplitude on cold stages is less than ±1 μm. Therefore, during development of the low vibration cooling systems for CLIO, we introduced advanced countermeasures for commercial PT cryocoolers. The cooling performance and the vibration amplitude were evaluated. Results revealed that, 4 K and 80 K PT cooling systems, which have a vibration amplitude of less than ±1 μm and respective cooling performances of 4.5 K at a heat load of 0.5 W and 70 K at a heat load of 50 W, were developed successfully.