A High Heat Capacity Backup System for Sustaining Cryogenic Temperatures

The Navy seeks an ability to sustain superconductor operating temperatures for extended periods in the absence of active cryocooling. The Navy is currently developing small, unmanned, magnetic mine-sweeping vehicles that employ superconducting magnets, and one simple approach to minimize the vehicle size, weight, and power is to employ a solid-state heat absorption system that keeps the superconducting magnet system cold and operating for several hours after it is disconnected from a ship-based cryocooler. Navy ships are also transitioning to superconducting systems for power distribution and degaussing, and cryocoolers maintain the cryogenic temperatures required for superconductor operation. When cryocooler electrical power is lost or interrupted for more than a brief period (such as during power source transfer), these systems begin warming to temperatures at which the superconductors no longer function. When power is restored, the superconducting systems must be re-cooled to restore functionality, resulting in additional time without full power distribution capability. In a prior Phase I SBIR project, Creare showed the feasibility of our solid-state heat-absorbing technology for sustaining superconductor operating temperatures for up to several hours in the absence of active cooling. Our technology is dimensionally stable during thermal cycling and efficient in terms of added size and weight. In this proposed Phase II Base project, Creare will advance the technology designs and performance estimates and then produce and test a sub-scale heat absorption assembly. The test results will confirm the technologyÆs effectiveness and further tune and validate our performance models. In the proposed Phase II Option, Creare will design and produce an operational prototype heat absorption system for the NavyÆs magnetic mine-sweeping application and deliver it to the Navy for testing with a superconducting solenoid system.