PULSE TUBE REFRIGERATOR

PROBLEM TO BE SOLVED: To assure high reliability and redundancy so as to continuously operate without interrupting an operation even by generating a fault in a compressor of a pulse tube refrigerator. SOLUTION: In the pulse tube refrigerator comprising a compressor, a cold thermal storage unit, a pulse tube, a reservoir tank, and an expansion unit made of a cold head, a main compressor 5I, a spare compressor 5II are connected to refrigerant piping communicating with the expansion unit 8 through a three-way valve 9. In this case, the one compressor 5I is normally driven to be operated. If a fault occurs in the compressor, the valve is switched, the other compressor 5II is driven to control to continuously operate the refrigerator. Its control means has a regulator 10 for detecting a temperature of the head of the unit during operating of the refrigerator to output a switching signal under the conditions of raising the detected temperature to a specified temperature or higher, and a relay unit 11 for switching the valve and the compressor according to a signal of the regulator.