A combined technique of nuclear reaction analysis and plasma-driven permeation for a quantitative study on deuterium trapping

Abstract

A new method of the in-situ depth-profiling technique was developed, in which the deuterium depth profile by nuclear reaction analysis (NRA) and the deuterium permeation flux of the plasma-driven permeation (PDP) were observed at the same time for a sample membrane, one side of which was continuously exposed to a deuterium plasma. The dissolved deuterium concentration in the sample was known from the permeation flux of the PDP and the trapped deuterium concentration was obtained from NRA. The trapping energy for deuterium in nickel, which was prebombarded with 0.8 MeV 4He ions, was determined from the observations at the steady state at sample temperatures of 398 to 685 K. It was 0.24 eV, which suggested that the traps were associated with vacancies produced by the 4He bombardment. This was supported by the fact that the depth profile of the trapped deuterium agreed well with the estimated distribution of the displaced host atoms.