This paper reviews recent advances in pulse tube cryocoolers and their application for cooling infrared sensors. There are many advantages of pulse tube cryocoolers over Stirling cryocoolers associated with the absence of moving parts in the cold head. Efficiencies have been improved considerably in the last few years to where they equal or even exceed the efficiencies of Stirling cryocoolers. The use of inertance effects and double inlets to improve the efficiencies will be discussed. Pulse tube cryocoolers are now being used or considered for use in cooling infrared detectors for many space applications. One disadvantage of pulse tube coolers is the difficulty in scaling them down to sizes as small as 0.15 W at 80K while maintaining high efficiency. A second disadvantage is the larger diameter cold finger required for the same refrigeration power because of the presence of the pulse tube. These two disadvantages have limited their use so far in cooling infrared sensors for many military tactical applications. Progress in overcoming these disadvantages is discussed.
"Pulse tube cryocoolers for cooling infrared sensors", Proc. SPIE 4130, Infrared Technology and Applications XXVI, (15 December 2000); doi: 10.1117/12.409878; https://doi.org/10.1117/12.409878