Description: The goal is to develop and test a 1 W at 20K Joule-Thomson cryocooler using an electrochemical compressor. A Joule Thomson refrigerator based on electrochemical hydrogen compression (EHC) offers many benefits, including: • Hydrogen has superior refrigerant properties than helium • Hydrogen offers isothermal heat exchanger between 15K -30K • EHC uses DC power, easy to integrate • EHC has no moving parts: low maintenance & easy to fabricate • EHC requires no lubrication, no oil separator systems • EHC architecture has commonality w\\ fuel cells and electrolyzer

Benefits: Develop and test a 1 W at 20K Joule-Thomson cryocooler using an electrochemical compressor. Cryocooler development and integration are both listed as a high priority technology need in TA-14 of the OCT Roadmap. 20K cryocoolers are relevant for multiple applications including zero boil off of chemical and nuclear propellants, liquefaction of ISRU gasses, cooling of IR detectors for science missions and cooling of superconducting cables and magnets.