Refrigeration for low temperature (77 K) electronics

The authors discuss the present state of the art and options that are being pursued to develop cryogenic coolers that will help make cryogenic electronic systems competitive. The discussion focuses on commercial systems operating in the 77-K temperature region with cooling requirements of about 10 to 1000 W. It is noted that the present perception is that the initial plus operating cost is too high and the life/service interval too short for Gifford McMahon refrigerators to make cryogenic electronic devices competitive with room-temperature devices. Stirling refrigerators offer the promise of lower costs and longer life; it will, however, take a number of years to realize the promise. High reliability in the refrigerator will make it possible to use the lower cost method of direct mounting the electronic device to the refrigerator