Miniature Cryogenic Refrigerator Turbomachinery

Potential applications of cryogenics to electrical, apparatus and superconducting devices have recently resulted in an extensive cryogenic refrigeration system program. Much of the effort in this program has been directed toward the research and development of small refrigeration systems for loads at liquid helium temperatures and with long-life components. In addition, the cryogenic refrigeration system program has emphasized the test evaluation of advanced performance, high-reliability turbomachinery components. Some of these developments are discussed here and special attention is devoted to high pressure-rise dynamic compressors, low-loss turboalternator design approaches, and component test results.