Zero Boil Off System for Cryogen Storage

This work proposes to develop a zero boil off (ZBO) dewar using a two-stage pulse-tube cooler together with two innovative, continuous-flow cooling loops and an actively cooled shield. While a number of cryogenic refrigeration systems may be considered for such applications, none offers the same potential for low vibration, high reliability, and high efficiency as the pulse tube. The continuous-flow cooling loops are made possible by the presence of rectifying interfaces that convert the oscillating flow of the pulse-tube cryocooler into a steady flow of cold refrigerant gas that can readily be distributed throughout the volume of the dewar or over the surface of a shield, without need for a separate circulating pump.