Thermophysics of the phenomena of gradientless heat transfer in porous solid cryogens: 1. Theoretical fundamentals for metallic conductivity of porous solid cryogens

Abstract

Earlier we found anomalously high thermal conductivity for certain porous solid cryogens, which was close to metallic thermal conductivity. In this paper the theory which accounts for this phenomenon is proposed. It is based on the concept of a new sublimation-filtration-condensation mechanism of heat transfer in porous structures with high saturated vapour pressure. The λ-like character of the variation in effective thermal conductivity with its maximum near the temperature corresponding to the saturated vapour pressures 0.25-0.3 of the triple point pressure, is predicted for such systems.