Radioactively induced sublimation in solid tritium

A horizontal cylindrical cavity bounded by isothermal walls was partially filled with liquid tritium which was then frozen by reduction of the temperature to 1.0 K below the triple point. Visual observations revealed that the solid subsequently redistributed itself into a layer of uniform thickness covering the complete interior of the cavity. The time constant for this effect depends on the age (or ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ content) of the tritium and not on the initial filling fraction. Time constants of 14.9, 92, 219, and 234 min were measured for tritium 0.04, 7, 16, and 17 days old, respectively.