Sorption compressor/mechanical expander hybrid refrigeration

J. A. JonesApplied Technol ogles SectionM. BritcliffeRadio Frequency and Microwave Subsystems SectionExperience with DSN ground-based cryogenic refrigerators has proved the reliabilityof the basic two-stage Gifford-McMahon helium refrigerator. A very long life cryogenicrefrigeration system appears possible by combining this expansion system or a turboexpansion system with a hydride sorption compressor, in place of the usual motor-driven piston compressor. To test the feasibility of. this system, a commercial Gifford-McMahon refrigerator was tested using hydrogen gas as the working fluid. Although noattempt was made to optimize the system for hydrogen operation, the refrigeratordeveloped 1.3 W at 30 K and 6.6 W at 60 K. The results of this test and of theoreticalperformances of the hydrid compressor are presented, coupled to these expansionsystems.