Charcoal/Nitrogen Adsorption Cryocooler

Refrigerator with no wear-related moving parts produces 0.5 W of cooling at 118 K. When fully developed, refrigerator needs no electrical power, and life expectancy of more than 10 yr, operates unattended to cool sensitive infrared detectors for long periods. Only moving parts in adsorption cryocooler are check valves. As charcoal is cooled in canister, gas pressure drops, allowing inlet check valve to open and admit more nitrogen. When canister is heated, pressure rises, closing inlet valve and eventually opening outlet valve.