Development of a low-cost cryocooler for HTS applications

Cryogenic refrigeration is an essential and enabling technology for the commercialization of high temperature superconducting (HTS) devices. A reliable, low-cost, low-vibration cryocooler, designed for efficient integration with HTS devices must be commercially available before HTS electronic technology can be introduced into the market place. To satisfy the need of HTS applications, the Low Cost Cryocooler (LCC) Program has been initiated. The LCC design is based on a combination of new technology and upgraded existing commercial designs. The goal is to hasten the insertion of HTS technology into the military and commercial communities by proving that cryocooler technology exists for the right price and demonstrating that this technology is low risk and reliable. The LCC Program is sponsored by the Advanced Research Projects Agency (ARPA) and the Naval Research Laboratory (NRL). This program will demonstrate a cryocooler operating in the 60K to 80K range (4 W at 70K) and satisfying the requirements of a number of HTS applications. The LCC design incorporates a unique compact and mechanically robust version of a pulse tube expander that offers cost, structural and thermal management advantages over other type expanders. The LCC compressor is an upgraded design of a linear twin-opposed piston design embodied in Hughes tactical and commercial coolers already in production. When integrated with the HTS device or other similar devices, this combination provides the system designer with a standard ''plug-in'' module. This paper describes the overall LCC system, its design, performance and manufacturing philosophy.