EXPERIMENTAL RESEARCH ON A 13.5 K GAS-COUPLED TWO-STAGE HIGH FREQUENCY PULSE TUBE CRYOCOOLER

High frequency pulse tube cryocoolers have been widely used in many fields like physics experimental research and aerospace，for no moving part in cold region，low vibration and long life.A gas-coupled two-stage high frequency pulse tube cryocooler with single compressor is introduced in this paper.In the first stage of the cryocooler，double-inlet and multi-bypass has been adopted as phase shifters.To get a better performance in phase shifting the reservoir and the inertance tube of the second stage has been located on the cold head of the first stage.A stream of gas has been introduced from the compression chamber to the hot end of the second stage as the double-inlet of the second stage，in order to shift the phase difference of the mass flow and the pressure wave.With the charge pressure of 1.7 MPa，input power of 250 W，the no-load temperature of 13.5 K and the cooling capacity of 0.6 W@30 K has been achieved.The experiment has been reported.