Abstract: With compact size and low mass, the ultra-high frequency pulse tube has got big attention for space application and has become the frontier of the pulse tube research. For simple configuration and easy to debug, the in-line type pulse tube cryocooler is fabricated and optimized on the basis of simulation calculation firstly. Then the coaxial pulse tube with same dimension of the in-line pulse tube is fabricated. The cold finger of the coaxial pulse tube has 9 mm outer diameter, 40 mm length and mass of 250 g mass.After the match of compressor and the optimization of the double inlet, driven by a liner compressor designed for 50 Hz operating at 90 Hz, the no-load temperature reaches to 46.4 K, and the cooling power is 2.1 W at 80 K with 80 W electric power input. Because of the low mass and the high operating frequency, the temperature of the cold end can decrease to working temperature 80 K from room temperature 300 K in two minutes and the gravity has little effect on the performance.

Key words: Coaxial, Miniature, Pulse tube cryocooler, Ultra-high frequency