DEUTERIUM RETENTION IN DAMAGED TUNGSTEN

In this research, thermal desorption characteristics of deuterium retained at trap sites of W created by irradiation of 300 keV hydrogen ions have been studied. With 10 hours of annealing, about 85% of deuterium was desorbed at temperatures of 300 degrees C and 350 degrees C, while deuterium desorption at 250 degrees C was about 60%. To estimate trapping energy of trap sites in this damaged W, TMAP simulation was performed. The result shows that the trapping energy of 1.29eV well accounted fir the result of 250 degrees C annealing. In view that in the literature the vacancy trapping energy of hydrogen in tungsten was estimated to be close to 1.43 eV and the sensitivity analysis has given an uncertainty for the trapping energy of the order of 0.1 eV, it appears that the dominant trapping site type in the investigated damaged tungsten consists of vacancies.