Development of a low-cost unlimited-life pulse-tube cryocooler for commercial applications

Our low-cost unlimited-life pulse-tube cryocooler was developed under a NASA cooperative program for high-temperature superconducting (HTS) cellular phone applications. Team members include the Lockheed Martin Advanced Technology Center, Superconductor Technology Inc., the National Institute of Standards and Technology, and the NASA Goddard Space Flight Center. This paper reports on the development of the pulse tube and one of the two compressor types developed. The Lockheed Martin (LM) compressor described utilizes a moving magnet design combined with self-aligning flexure supports in combination with a co-axial pulse tube. This approach evolved specifically to reduce production costs while maintaining the unlimited lifetime and high reliability of the spaceborne flexure systems. Early testing of an in-line pulse tube shows 3.7 W of cooling at 77 K and no life limitation. The coaxial version was also developed and provided cooling at the same level. Production costs, based largely on actual parts quotes, are estimated at under $2,000, including the electronic controller, for quantities of 10,000 units per year.