Experiments on deuterium trapping in helium-irradiated copper

Deuterium trapping in helium-irradiated copper was experimentally studied by use of nuclear reaction analysis (NRA). During the irradiation and the NRA, the sample was continuously charged with deuterium by exposure to deuterium plasma and the permeation flux was monitored. Before the irradiation, the deuterium concentration near the plasma-exposure surface was 2.2 × 1022 m−3 at 398 K while it increased by 10,000 times after the irradiation with a dose of 1.5 × 1021 m−2. From the shape of the depth profile of trapped deuterium and its temperature dependence, it was found that two types of the traps were produced. One was considered to be vacancies and the other probably interstitial loops. These traps were not annihilated even at 575 K.