Hydrogen isotope permeation and desorption dynamics in W-Re alloys

Abstract

In this study, deuterium permeation and desorption in Fe2+ damaged tungsten (W) and W-10%Re were evaluated using plasma-driven permeation (PDP) and thermal desorption spectroscopy (TDS). The addition of rhenium (Re) decreased the diffusion coefficient of hydrogen isotopes and increased the permeation flux relative to W. Microstructural changes caused by the addition of Re include a reduction in grain size are thought to enhance diffusion paths within the bulk, leading to an enhancement of the permeation flux. We also observed that trapping of D by radiation-induced defects for W-10%Re was smaller than that for W. Based on TDS measurements, D retention for 1 dpa damaged W was higher than that for 0.1 dpa damaged W. However, there was no significant difference for D retention for W-Re which suggested that the irradiation defects as the trapping sites were saturated less than 0.1 dpa. We hypothesize that the addition of Re suppresses the generation of stable trapping sites and reduces the damage level required to reach the D saturation.