Incident energy dependence of blistering at tungsten irradiated by low energy high flux deuterium plasma beams

Luo, G.; Shu, Wataru; Nishi, Masataka

Polycrystalline tungsten samples have been irradiated at room temperature by high flux (110 D/m/s) deuterium plasma beams with incident energies ranging 7 98 eV/D. Surface blistering occurred at all energies. The critical fluence for blistering was found to increase with decreasing the incident energy. At energies 20 eV/D, increased more rapidly. This energy dependence of may be explained by a proposed model dealing with the oxide barrier to deuterium uptake into and release from the bulk W. At all energies, the blisters increased in their size and number with fluence within the corresponding low fluence ranges. However the size stopped increasing at certain fluences, while the number kept increasing within the experimental fluence range, which could be attributed to rupturing of blisters at a certain size of about 2m.