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 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 brassboard two-stage 10 K cryocooler that demonstrates the performance benefits of the technology. During the Phase I project, we will obtain key operational and performance data on one of the primary cryocooler components. The data will be used to predict the performance and to guide the development of the two-stage cryocooler that will be tested on the Phase II project. During the Phase II project, we will implement the component and cryocooler modifications determined during Phase I, integrate the cryocooler components, and test the cryocooler at cold load temperatures as low as 10 K.