Abstract
A Pulse tube cryocooler of simple structure without moving part in the expander has the advantage over a stirling cryocooler of low vibration and long life. So its wide uses for space crafts and high-temperature superconductor devices are extended. Recently Fuji Electric has developed a pulse tube cryocooler with cooling capacity of 2.5W at 70K, based on the technology of the stirling cryocooler for the space crafts. The cryocooler consists of a compressor with two opposite pistons supported by flexure bearings and an in-line type pulse tube expander. This paper describes the structural features, typical performances and reliability of the new cryocooler.