Tritium transport and retention in SiC

Abstract

A theoretical framework describing trapping, diffusion, and desorption of tritium from vapor-deposited β-silicon carbide has been proposed and an analytical version of this model was derived. This analytical model was used to extract trapping, diffusion, and desorption parameters from a limited part of the experimental data set. The predictive capability of the resulting parameter-free model was then tested by calculating the time-dependent release behavior for the high-temperature regimes. These results generally agreed with the release data, supporting the suitability of that approach. Tritium trapping was found to be strong. Both bulk diffusion and surface desorption make comparable contributions to tritium release from the silicon carbide. Improvements beyond the present analytical model, such as dynamical detrapping, can be achieved with the proposed framework.