Experimental investigation of pulse tube refrigerator with rod type displacer as phase shifter

Pulse tube refrigerator with rod type displacer as phase shifter has higher theoretical efficiency. A preliminary experiment just got efficiency less than 10%. The refrigerator is improved by changing the linear compressor with a new one for studying its basic character in this paper. A Relative Carnot efficiency of 15.3% is obtained at 99.8 K with 30.0 W cooling power. There is an optimum voltage for efficiency. Cooling power can be adjusted in a wide range with voltage change without big loss of efficiency, which is a very unique character of displacer type pulse tube refrigerator.