An overview is provided of the present state-of-the-art of miniature (less than 3 Watt capacity at 80 K) Stirling cycle cryogenic coolers currently in development at Hughes Aircraft Company. These coolers offer high operating efficiency and significantly improved reliability which are key factors for emerging commercial applications requiring the use of cryogenic cooled sensors. Characteristics of rotary drive compressor designs as well as linear oscillating compressor designs are reviewed. Recent developments in affordable linear cooler designs for commercial applications are summarized. The significant growth in operational reliability of Stirling cycle coolers over the past ten years is discussed, showing a growth in Mean Time to Failure (MTTF) from a few hundred hours in 1980 to 2000 to 5000+ hours today. Over 100,000 hours of reliability testing of Hughes Stirling cycle coolers at varied ambient temperatures are summarized to support the cited growth in cooler reliability. Recent reliability growth in linear drive coolers offers the benefit of easily interfacable designs with extended operating periods requiring maintenance at 4000 to 8000 hours of operation intervals. Performance data on a range of rotary drive and linear drive coolers are summarized to indicate the range of performance currently available for commercial applications. A summary of performance characteristics of a higher capacity linear cooler with structural rigid coldfinger for integration with large area advanced detector arrays is provided. Its combination of high capacity, structural stability, cost effectiveness and inherent reliability make this an attractive cooler for integration with advanced imagers incorporating large focal plane arrays.
Gerald R. Pruitt,
"Status of cryogenic coolers for commercial infrared applications", Proc. SPIE 1762, Infrared Technology XVIII, (5 January 1993); doi: 10.1117/12.138983; https://doi.org/10.1117/12.138983