Beta heating driven deuterium–tritium ice redistribution, modeling studies

Abstract

We have previously demonstrated, based upon a one-dimensional analysis, that beta heating could cause a redistribution of nonuniform deuterium–tritium (DT) ice within a cryogenic target at an ideal rate that would decrease nonuniformity by a factor of 10 every hour. Our analysis was extended to address two pertinent questions: for a spherical target, where will the DT ice finally go and how quickly will it get there? This analysis is a two-dimensional heat and mass transfer problem. We have used PLTMG, a state-of-the-art multigrid computer code for the analysis. For the ‘‘tent’’ mount method of positioning a target in a cryogenic enclosure, an ice layer nonuniformity of <1% can be achieved. We have evaluated the rate of ice redistribution and report its variation as a function of 3He content within the target, the target temperature, target geometry, and thermal conductivity of the shell wall.