A high efficiency coaxial pulse tube cryocooler operating at 60 K

In recent years, improved efficiency of pulse tube cryocoolers has been required by some space infrared detectors and special military applications. Based on this, a high efficiency single-stage coaxial pulse tube cryocooler which operates at 60 K is introduced in this paper. The cryocooler is numerically designed using SAGE, and details of the analysis are presented. The performance of the cryocooler at different input powers ranging from 100 W to 200 W is experimentally tested. Experimental results show that this cryocooler typically provides a cooling power of 7.7 W at 60 K with an input power of 200 W, and achieves a relative Carnot efficiency of around 15%. When the cooling power is around 6 W, the cryocooler achieves the best relative Carnot efficiency of around 15.9% at 60 K, which is the highest efficiency ever reported for a coaxial pulse tube cryocooler.