HIGH-TC SUPERCONDUCTING COMPOSITES FOR INTERCONNECTS TO CRYOGENIC EQUIPMENT

A VACUUM-DEPOSITION PROCESS THAT PROMOTES CRYSTAL-LOGRAPHIC ORIENTATION AND HIGH CRITICAL CURRENTS IN YBA2CU3O7-X FILMS DEPOSITED ON CERAMIC SUBSTRATES WILL BE DEVELOPED AS A MEANS OF FABRICATING FLEXIBLE ELECTRICAL INTERCONNECTS TO CRYOGENIC EQUIPMENT IN THE SPACE ENVIRONMENT. THE INTERCONNECTS WILL COMPRISE A THIN FILM OF HIGH-JC YBA2CU3O7-X, DEPOSITED ONTO FLEXIBLE CERAMIC TAPES AND FILAMENTS, A BUFFER LAYER, A VACUUM- DEPOSITED OXIDE OVERLAYER, AND A LOW OUT-GASSING, POLYMER ENCAPSULANT. METHODS FOR REDUCING BOTH CONDUCTIVE- AND RADIANT- HEAT TRANSFER ARE INCORPORATED INTO THE DESIGN. THE INTERCONNECTS WOULD HAVE SIGNIFICANTLY LOWER THERMAL CONDUCTIVITY, NO I2R LOSSES (FOR DC APPLICATIONS), AND WOULDBE OF EQUIVALENT OR LOWER WEIGHT THAN CONVENTIONAL METAL INTERCONNECTS. THE LOW THERMAL CONDUCTIVITY WILL MINIMIZE CRYOGEN (PRIMARY LIQUID-HELIUM) LOSS AND SIGNIFICANTLY INCREASE THE MISSION-LIFE OF SENSORS AND OTHER EQUIPMENT REQUIRING CRYOGENIC COOLING. THE PRINCIPAL TECHNICAL OBJECTIVE OF THE PHASE I PROGRAM IS TO DEMONSTRATE THE DEPOSITION OF HIGH-JC YBA2CU3O7-X (JC-10(6) A/CM(2) AT 77 K) ON FLEXIBLE TAPES AND FILAMENTS WITH AN IC OF 20 A AT 77 K). A VACUUM-DEPOSITION PROCESS THAT PROMOTES CRYSTAL-LOGRAPHIC ORIENTATION AND HIGH CRITICAL CURRENTS IN YBA2CU3O7-X FILMS DEPOSITED ON CERAMIC SUBSTRATES WILL BE DEVELOPED AS A MEANS OF FABRICATING FLEXIBLE ELECTRICAL INTERCONNECTS TO CRYOGENIC EQUIPMENT IN THE SPACE ENVIRONMENT. THE INTERCONNECTS WILL COMPRISE A THIN FILM OF HIGH-JC YBA2CU3O7-X, DEPOSITED ONTO FLEXIBLE CERAMIC TAPES AND FILAMENTS, A BUFFER LAYER, A VACUUM- DEPOSITED OXIDE OVERLAYER, AND A LOW OUT-GASSING, POLYMER ENCAPSULANT. METHODS FOR REDUCING BOTH CONDUCTIVE- AND RADIANT- HEAT TRANSFER ARE INCORPORATED INTO THE DESIGN. THE INTERCONNECTS WOULD HAVE SIGNIFICANTLY LOWER THERMAL CONDUCTIVITY, NO I2R LOSSES (FOR DC APPLICATIONS), AND WOULDBE OF EQUIVALENT OR LOWER WEIGHT THAN CONVENTIONAL METAL INTERCONNECTS. THE LOW THERMAL CONDUCTIVITY WILL MINIMIZE CRYOGEN (PRIMARY LIQUID-HELIUM) LOSS AND SIGNIFICANTLY INCREASE THE MISSION-LIFE OF SENSORS AND OTHER EQUIPMENT REQUIRING CRYOGENIC COOLING. THE PRINCIPAL TECHNICAL OBJECTIVE OF THE PHASE I PROGRAM IS TO DEMONSTRATE THE DEPOSITION OF HIGH-JC YBA2CU3O7-X (JC-10(6) A/CM(2) AT 77 K) ON FLEXIBLE TAPES AND FILAMENTS WITH AN IC OF 20 A AT 77 K).