Temperature dependence of blistering and deuterium retention in tungsten exposed to high-flux and low-energy deuterium plasma

Shu, Wataru; Isobe, Kanetsugu; Yamanishi, Toshihiko

At 315 K, only sparse low-dome blisters appeared even the fluence was increased to 10 D/m. At around 400 K, the blisters became much denser and the dome of blisters became a little higher. Peculiar change occurred around 500 K, where two kinds of blisters appeared. One is the large blisters with sizes of a few tens of microns and varying ratios of height against chord (up to 0.6), and the other is the small blisters with chords of less than a few microns and large ratio of height against chord (about 0.7). In high temperature region (higher than 600 K), the blisters became much sparser with the increasing temperature and disappeared at 1000 K. Deuterium retention showed the maximum around 500 K, corresponding to the appearance of two kinds of high-dome blisters.