Demonstration of a 10 K Multistage Cryocooler

Advanced space-borne infrared detectors require cooling at temperatures near 10 K. Cooling loads for these detectors will range from 0.25 W to 1.0 W at 10 K, with additional loads at higher temperatures. A multistage cooler, capable of cooling multiple loads, will offer large potential gains in system efficiency and weight. Turbomachine-based Brayton cryocoolers are ideal candidates for these missions because they are highly efficient, lightweight, vibration-free, adaptable to multiple stages, and have long maintenance-free lifetimes. State-of-the-art technology exists or is under development for all primary cryocooler components. During this program, we propose to build and test a two-stage 10 K cryocooler that demonstrates the performance benefits of the technology. During the Phase I project, we obtained key operational and performance data for one of the primary cryocooler components. The data were used to predict the performance and guide the development of the two-stage cryocooler that will be tested during the Phase II project. During the Phase II project, we plan to configure and test the cryocooler at cold load temperatures as low as 10 K.