The Behavior of Fission Products Captured in Graphite Powder by Nuclear Recoil. IV. Further Studies on the Diffusion of Xenon-133 in Graphite

Abstract

Experiments were carried out on artificial graphite and natural graphite- 1 and graphite-2. The experiment on natural graphite-2 showed no striking effect of the rate of temperature increase; the amount (46.3%) of Xe-133 released when the temperature of a graphite sample was increased from room temperature to 800 deg C in 3 min and kept constant at 800 deg C for 90 min was nearly equal to the amount (41.7%) of Xe-133 released when the temperature of another sample was increased from room temperature to 800 deg C at a rate of 3 deg C/min. Therefore the amount of Xe-133 released is mainly determined by a final temperature. The activation energy of diffusion in artificial graphite was found to be a little higher than that in natural graphite. Heating curves are given to show the distribution of the amount of released Xe over a wide range of temperature. (P.C.H.)