A RELIABLE, LONG-LIFETIME CLOSED-CYCLE CRYOCOOLER FOR SPACE

THERE IS A STRONG NEED FOR SIMPLE, RELIABLE CLOSED-CYCLE CRYOCOOLERS CAPABLE OF PROVIDING APPROXIMATELY 5 WATTS OF REFRIGERATION AT TEMPERATURES NEAR 65-75 K. THE MOST PROMINENT EXAMPLE OF CURRENT APPROACHES IS THE LINEAR STIRLING CYCLE UNDER SPONSORSHIP OF NASA. RECENT TECHNOLOGICAL DEVELOPMENTS IN THE MINIATURIZATION OF GAS BEARINGS AND TURBINES INDICATE THAT A REVERSE-BRAYTON CYCLE USING TURBOMACHINES MAY BE AN ATTRACTIVE ALTERNATIVE TO THE USING TURBOMACHINES MAY BE AN ATTRACTIVE ALTERNATIVE TO THE LINEAR STIRLING CRYOCOOLER. THIS PHASE I PROGRAM EVALUATES THE FEASIBILITY OF DEVELOPING A 5 WATT, 70 K CRYOCOOLER BASED ON ROTATING TURBOMACHINES IN A REVERSE-BRAYTON CYCLE. THE OBJECTIVE OF PHASE I IS TO ESTABLISH THE SIZES AND TYPES OF HARDWARE REQUIRED TO MEET THE 5 W LOAD AT 70 K. THE EFFORT WILL ESTABLISH WHETHER CURRENT TECHNOLOGY CAN MEET THIS APPLICATION AND WHAT DEVELOPMENTS MUST TAKE PLACE TO DEMONSTRATE A WORKING PROTOTYPE.