An experimental investigation of a single-stage two-pulse-tube refrigerator

A single stage orifice pulse tube cryocooler incorporating one compressor and regenerator, but two pulse tubes has been constructed and tested. This development is directed toward use as cooling for superconducting current leads where the voltage insulation between the two leads is critical. The purpose of the present study is to investigate the thermal stability of parallel oscillating flows and compare the performance of a specific pulse tube in a two-tube configuration with that of the same pulse tube working in the standard single tube configuration. Performance is characterized by the system cool-down speed and the minimum cold end temperature. Three pulse tube specimens named I, II, and III, have been assembled and tested individually and in various combinations. The experimental results reveal the absence of any thermal stability problem in the two pulse tube configuration. However, the performance of a specific pulse tube is degraded in the two-tube configuration as compared to its individual use.