Investigation of gas and plasma driven deuterium permeation through a vanadium membrane for particle exhaust application in a fusion reactor

The process of particle exhaust based on the cryopump in fusion reactor presents a severe issue of deuterium and tritium retention. However, the metal foil permeation pump represents an effective means to solve the problem of deuterium and tritium retention during the particle exhaust process. How to enhance the permeability performance of metal films to meet the requirements of practical engineering applications of fusion reactor is the main content of the research. This article focuses on the simulation and experimental investigation of V membrane, aiming to explore methods for enhancing membrane permeation flux. Through simulation analysis, the influence of thickness, membrane surface state, and temperature on both plasma-driven and gas-driven permeation has been studied. Among these, the downstream surface condition is changed during the PDP process, resulting in an almost twofold increase in permeation flux. Based on the permeation experiments the influence of temperature on permeation was proved and the impact of plasma source power on permeation was also studied. It was found that the permeation flux increased more than two orders of magnitude when the radio frequency power changed from 0 to 500 W, which indicates that plasma incident flux serves as a more effective means to enhance permeation flux compared to temperature.