Electron irradiation experiments in support of fusion materials development

Microstructal evolution in response to 1 MeV electron has been investigated for three simple ferritic alloys, pure beryllium pure vanadium, and two simple vanadium alloys over a range of temperatures and doses. Microstructural evolution in Fe-3Cr, Fe-9Cr and Fe-ferritic alloys is found to consists of crenulated, faulted a <100> loops and circular, unfaulted 1/2a <111> loops at low temperatures, but with only unfaulted loops of both types at high temperatures. The complex dislocation evoluted is attributed to sigma phase precipifaults arising from chromium segregation to point defect sinks. Beryllium is found to be resistant to electron damage; the olny effect observed was enhanced dislocation mobility. Pure vanadium, V-5Fe, and V-1Ni microstructural response was complicated by precipitation on heating to 400 deg C and above, but dislocation evolution was investigated in the range of room temperature to 300 deg C and 600 C. The three materials behaved similarly, except that pure vanadium showed more rapid dislocation evocation. This difference does not expaint the enhanced swelling observed in vanadium alloys. (orig.)