Development of a Two-Stage Alternate Joule-Thomson Cryo-Cooler for AAWS-M RiskReduction

摘要

The latest in infrared imaging Focal Plane Array (FPA) technology incorporatesMercury Cadmium Telluride, a material that must be cooled to liquid nitrogen temperatures for operation. Fast cool-down, within five seconds, has been achieved under a harsh temperature environment (71 deg C). A Joule-Thomson Cryo-cooler employing two heat exchanger stages has been developed. High pressure Krypton flows through one stage, providing initial pre-cooling, while high pressure Nitrogen simultaneously flows through the other stage. The two-stage gas flow approach along with the superior pre-cooling properties of Krypton enable cool-down under five seconds.