Experimental study for thermal conductivity structure of lunar surface regolith: Effect of compressional stress

We measured the thermal conductivity of glass beads as a simple model material in order to investigate the compressional stress dependence of the thermal conductivity of powder materials. The measurements were conducted in a vertically elongated cylindrical sample container under vacuum conditions. Our results suggest that the compressional stress is one of the essential factors to understand the thermal conductivity structure in the regolith layer.