Bi-directional hydrogen permeation through F82H under DEMO-relevant conditions

Using a laboratory-scale plasma device, plasma-driven and gas-driven permeation of hydrogen through a ferritic steel alloy: F82H has been investigated under some of the DEMO-relevant conditions. The steady state plasma-driven permeation flux has been found to be strongly affected by the variation in upstream surface morphology resulted from plasma bombardment. The activation energy of permeability for gas-driven permeation has been estimated to be ∼0.5 eV, which is close to the result of plasma-driven permeation. Gas-driven permeation can occur in the opposite direction of plasma-driven permeation, which then results in an increase in first wall recycling. (author)