Blistering and Helium Retention of Tungsten and 5％ Chromium Doped Tungsten Exposed to 60 keV Helium Ions Irradiation

摘要

Pure tungsten (W) and chromium doped W (W-5％Cr) are prepared by powder metallurgy.The microstructure,blistering and helium retention are investigated by x-ray diffraction,scanning electron microscopy,transmission electron microscopy and thermal desorption spectroscopy (TDS).These results show that the average size and density of helium blisters on the surface of pure W are much larger than those on the W-5％Cr alloy.Vacancyimpurity pairs can reduce the migration coefficients of vacancy and vacancy-helium complexes,and Cr may play a role of such an impurity.Moreover,the TDS result shows that the highest desorption peak moves to higher temperature,which is attributed to the Hem Crk Vn complexes in the W-Cr alloy.In addition,the helium retention is found to be higher in W than in W-5％Cr.