Experiment on a Single-stage GM Type Pulse Tube Cryocooler near 20K

Publisher Summary This chapter presents an experiment on a single-stage GM type pulse tube cryocooler. The minimum temperature 22.4K and cooling power 5.65W at 80K are obtained with 2kW input power, when the double-inlet measure consists of two parallel needle valves in the inverse directions, and the regenerator matrix consists of phosphor bronze screens and stainless steel screens of 247 mesh alternation. Furthermore, the minimum temperature of a single-stage pulse tube cryocooler with the double-valved configuration is below 13K, driven by a 13kW compressor. It indicates that DC flow in the pulse tube refrigerators will be controlled well with double-valved configuration. During 24-hour uninterrupted operation, the minimum temperature fluctuation is less than 0.3K, which could meet the requirement of the application in the realm of superconductivity. At about 20K, the volume specific heat capacity of helium is much higher than those of the stainless steel screens and phosphor bronze screens, so the performance of the regenerator is deteriorated.