Compact Linear Split Stirling Cryogenic Cooler for High Temperature Infrared Imagers

Presented at the 16th International Cryocooler Conference, held May 17-20, 2008 in Atlanta, Georgia.Novel high-definition night vision imagers are being enabled by new high-temperature infrared detectors that operate at elevated temperatures ranging from 95K to 200K; these have performance indices comparable with those of their 77K predecessors. Recent technological progress towards industrial implementation of such detectors has motivated the development of microminiature split Stirling linear cryocoolers. These coolers have great potential to replace the traditionally used rotary integral Stirling coolers. Their known advantages are superior flexibility in system packaging, constant and high drive frequency, lower wideband vibration export, unsurpassed reliability, and aural stealth. Unfortunately, off-the-shelf available tactical linear coolers relying on flexural-bearing, contactless, dual-piston compressors are thus far oversized, overweight, overpowered, and overpriced as compared to their rotary competitors. The authors report on the successful development of the smallest in the range Ricor model K527 microminiature 1W at 95K split Stirling linear cryogenic cooler. This cooler relies on a single piston externally counterbalanced linear compressor, and was designed to provide cryogenic cooling to a wide range of forthcoming infrared imagers, particularly those where power consumption, compactness, vibration, aural noise, and ownership costs are of concer