Investigation on a 40 K high-frequency lightweight pulse tube cryocooler for space applications

40 K pulse tube cryocoolers hold significant potential for cooling quantum-well infrared photodetectors. In this work, key parameters for achieving weight reduction of pulse tube cryocoolers were analyzed theoretically. Numerical simulation and experimental verification were conducted on key parameters for achieving weight reduction and on the regenerator filling method that affects cooling performance. A lightweight pulse tube cryocooler utilizing only inertance tubes and gas reservoir as phase shifter achieved a cooling capacity of 2.9 W at 40 K with 200 W compressor input power, achieving a record-high relative Carnot efficiency of 9.5 % among reported 40 K pulse tube cryocoolers. The pulse tube cryocooler weighs 4.4 kg with a record specific mass of 0.66 W/kg—78 % higher than that of conventional 40 K pulse tube cryocoolers. This study validates a high-reliability, lightweight pulse tube cryocooler design for space quantum-well infrared photodetectors, achieving a balance between weight reduction and cooling performance through the synergistic effects of frequency, pressure, and regenerator optimization.