Influence of blistering on deuterium retention in tungsten irradiated by high flux deuterium 10-100eV plasmas

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

The influence of blistering on deuterium retention in W was investigated using the newly established plasma generator with controllable incident energies ranging from 100 eV down to around 10 eV and incident flux of 110 D/m/s. The retention in the irradiated samples was measured using a thermal desorption spectrometer (TDS) at a ramping rate of 5 C/s. The results indicate that only one peak appears in each spectrum, with the peak temperatures ranging from 500 until 850 C, much higher than those from the trapping sites like vacancies, grain boundaries, dislocation loops, or impurities, implying probably a direct origin from the molecules existing inside blisters, voids/bubbles. Significant decrease in the retention at a certain incident fluence after blister appearance was observed and attributed to rupturing of the blisters, consistent with the limited size and increasing number of the blisters with increasing the incident fluence, as observed by means of SEM.