Accession Number : ADA112622

Title :   Prototype Low Temperature Low Power Cryocooler,


Personal Author(s) : Pierce,Warren G

PDF Url : ADA112622

Report Date : Feb 1982

Pagination or Media Count : 56

Abstract : Over the past several years considerable interest has developed for low power, low cost mechanical cryocoolers for use in cooling SQUIDS and other superconducting devices. In 1977 Dr. Jim Zimmerman of National Bureau of Standards, Boulder, CO described a stirling cycle cryocooler that exhibited the following desirable characteristics: (1) Low input power (approximately 50 watts connected load); (2) Modest cooling capacity at very low temperature; (3) Constructed of non-ferromagnetic materials; and (4) Simple design. Dr. Zimmerman's intent was to demonstrate the feasibility of constructing a simple low power cryocooler capable of cooling an operational SQUID. After several modifications of the original cryocooler, Dr. Zimmerman successfully operated a point-Contact Nb SQUID on a four-stage stirling cycle cryocooler with a mechanical drive power of approximately 15 watts, and a capacity of few milliwatts at less than 9 Kelvin. During this period Lake Shore Cryotronics, Inc. successfully negotiated an exclusive licensing (for the U.S.) agreement with Oxford Instruments Ltd. concerning a simple patented single stage cryocooler utilizing a slide-valve-controlled gas driven displacer drive head, powered by a remote conventional high speed compressor. The lowest temperature achieved was less than 20 Kelvin with the two stage cylinder/displacer operating at a cycle rate of 2Hz, 100 psi inlet (pressure), and 20 psi outlet pressure.

Descriptors :   *Stirling cycle, *Cooling and ventilating equipment, *Cryogenics, *Superconductors, *Magnetometers, Prototypes, Low power, Low temperature, Communication equipment, Radio receivers

Subject Categories : Air Condition, Heating, Lighting & Ventilating
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE