Deuterium Transport and Retention in Liquid Ga and Li Under Steady-State Plasma Bombardment

The experiments on deuterium plasma-driven permeation through liquid Ga and Li were conducted in a linear plasma device VEHICLE-1. Deuterium transport parameters such as diffusivity and surface recombination coefficient for Ga and Li were measured from the experiments. By using the measured transport parameters, deuterium dynamic retentions in Ga and Li under steady-state plasma bombardment were evaluated with the DIFFUSE code. It has been found that the deuterium dynamic retention in Ga is ~five orders of magnitude lower than that in Li under present experimental conditions. After exposed to the steady-state deuterium plasma at temperatures from 78 °C to 360 °C, deuterium static retentions in liquid Ga are measured by the thermal desorption spectroscopy. It has been found that the deuterium static retentions in Ga are close to the dynamic retentions when the exposure temperatures are below 250 °C.