Space-Flight Assessment of a Small-Scale Collins Type Cryocooler Concept

A compact, reliable, efficient and inexpensive cryocooler requiring less than 1 kW of power for 2W of cooling at 10 Kelvin is being developed and will be demonstrated. This performance is at least twice as efficient as the best current state-of-the-artfor small low-temperature cryocoolers. The proposed technical approach, whose technical feasibility and suitability for space-based applications has been confirmed, is to apply the advantageous features of large-scale cryogenic refrigerators to compactand reliable small-scale systems by implementing a novel thermodynamic cycle in a mechanically innovative machine. Size, cost, and complexity are reduced in the proposed concept by employing a modular design whereby each stage is of identical construction(exept for length), and where the heat exchanger and expander are constructed as an integral unit. The expanders are of extremely simple floating piston construction that requires no seals or mechanical power transmission devices to extract power from thecold expander. Piston motion is controlled by electro-magnetically actuated