Neon gas-gap heat switch

A self-contained neon gas-gap heat switch featuring an internal charcoal adsorption pump has been developed and tested. This heat switch can be used with cold base temperature ranging from 17 K to 40 K offering an extension to sorption based helium gas-gap heat switch limited to below 20 K. For this prototype, an ON conductance about 74 mW/K and an OFF resistance about 3000 K/W were obtained, giving an ON/OFF conductance ratio about 220 at 20 K in agreement with calculations obtained from a simple model. These characteristics can be further optimized working on the geometry.