Experimental Study of a Single-Stage Coaxial Pulse Tube Cryocooler Aimed at Cooling Two Infrared Detectors

Space infrared detection is the most widely used platform of pulse tube cryocoolers (PTCs). The development of multi-stage PTC for simultaneous cooling of two or more detectors is discussed. However, its structural characteristics have the problems of large volume, heavy mass and uncompact structure. This paper aims to study the feasibility of multi-temperature cooling of single-stage PTC, to improve the compactness of the cryocooler. In the experiment, multi-temperature cooling of single-stage PTC is achieved by adding intermediate cooling at the cold finger. The large temperature gradient of the cold finger indicates the extra cooling potential. And the effect of the frequency on the temperature of the cold end and inter-stage is discussed. The experiment has also studied two-stage cooling performance under 100 W input power. The results show that the single-stage PTC with multi-stage cooling is feasible.