High Efficiency 10K Cryocooler for Space Application

A compact, reliable, efficient and inexpensive crycooler requiring less than 1kW of power for 2W of colling at 10K will be developed and demonstrated. This performance is at least twice as efficient as the best current state-of-the-art for smalllow-temperature crycoolers. The proposed technical approach, whose feasibility has been investigated and confirmed in Phase I of this project, is to apply the advantageous features of large-scale cryogenic refrigerators to compact and reliable smallscalesystems by impementing a novel therodynamic cycle in a mechanically innovation machine. Size, cost, and complexity are reduced in the proposed concept by employing a modular design whereby each stage is of identical construction (except for expanderand heat exchanger length), and where the heat exchanger and expander are constructed as an integral unit. The expanders are of extremely simply floating piston construction that requires no seals or mechanical power transmission devices to extract powerfrom the cold expander. Piston motion is controlled by electo-mechanically actuated