Advanced Tactical Cryocoolers for UAV Applications

Low temperature superconducting electronics have the potential to revolutionize digital communications from Unmanned Aerial Vehicles (UAVs), but must operate at cryogenic temperatures. Commercial cryocoolers are large and inefficient and are unable to meet size, weight, and power requirements for UAVs. Our approach and the innovation is a reverse turbo-Brayton cryocooler that provides refrigeration at 4.2 K and rejects heat at 77 K through boil-off of liquid nitrogen. The cryocooler is predicted to reduce size, weight, and input power by at least an order of magnitude as compared to the current state-of-the-art 4.2 K cryocooler. The nitrogen boil-off rate is reasonable, enabling long-duration UAV missions. Successful completion of this program will dramatically improve digital communications from UAVs. During the Phase I project, we finalized specifications for the cryocooler; designed the cryocooler and cryostat; determined the size, weight, and input power for the overall cryogenic system; and performed proof-of-concept testing on a critical cryocooler component. During Phase II, we propose to build and test a complete cryocooler.