Superfluid Stirling refrigerator with a counterflow regenerator

Conference · Sun Nov 01 04:00:00 EST 1992

OSTI ID:10108128

Brisson, J. G.; Swift, G. W.

The superfluid Stirling refrigerator (SSR) uses a {sup 3}He-{sup 4}He liquid mixture as a working fluid. It operates at temperatures below 2 K where the {sup 4}He component of the working fluid is superfluid. The {sup 3}He component of the working fluid, to first approximation, behaves thermodynamically like an ideal gas in the inert background of superfluid {sup 4}He. Using pistons equipped with a superleak bypass, it is possible to expand and compress the {sup 3}He solute ``gas.`` The SSR is a Stirling machine equipped with these ``superleaked`` pistons to take advantage of the properties of the {sup 3}He solute to cool below 1 K. The proof of principle was shown by Kotsubo and Swift in 1990. There are three other techniques for cooling below 1 K: (1) the {sup 3}He-{sup 4}He dilution refrigerator which utilizes the endothermic heat of mixing of {sup 3}He into {sup 4}He to reach temperatures below 0.010 K; (2) the evaporation of {sup 3}He which can reach temperatures of 0.3 K; and, (3) adiabatic demagnetization of a paramagnetic salt. There are several advantages of the SSR over each of the other techniques. The power consumption of a dilution refrigerator is typically on the order of kilowatts; whereas, the SSR consumes hundreds of watts. The SSR has the potential to cool below 0.3 K and out-perform the evaporative {sup 3}He refrigerator. Adiabatic demagnetization often requires magnetic shielding between the refrigerator and the object to be cooled; obviously, the SSR requires no such shielding. There is an interest in developing subkelvin cryocoolers for satellite-borne X-ray and infrared detectors. In space applications, the power consumption of an SSR can be reduced to tens of watts. This coupled with the SSR`s insensitivity to a zero G environment makes it an attractive option to cool detectors in space.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10108128
• Report Number(s): LA-UR--92-3853; CONF-921130--1; ON: DE93003858
• Country of Publication: United States
• Language: English

Related Subjects

661210
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMPARATIVE EVALUATIONS
CRYOGENICS
DESIGN
PERFORMANCE
REFRIGERATORS
STIRLING CYCLE
SUPERFLUIDITY