Development of Miniature Stirling Cryocooler Technology for Infrared Focal Plane Array

A reliable miniature cryocooler is one of the basic and foremost requirements for successful operation of high performance cooled infrared focal plane array (IRFPA) used for defence applications. Technological complexity and requirement of long duration fail-safe operation of the cryocooler demands robust design, fabrication and assembly with tolerances and, perfection of an array of sub-technologies. The paper presents the progress of the development activities in Stirling cryocooler technology at Solid State Physics Laboratory (SSPL), which evolved through essential milestones like the development of single and dual piston linear motor driven split coolers to the state-of-the-art integral Brushless DC (BLDC) motor crank-driven type highly miniaturized coolers of capacities ranging from 0.25 to 0.5W at 80K. The theoretical investigations in the design of Stirling cycle cryocooler have been reported and the issues related to the design aspects are discussed in sufficient details. Experimental results of cryocooler performance tests are also presented. The paper also focuses on regenerator design optimization. The results of optimizations have been shown at the end considering a sample data.