Effect of pre-damage induced by argon ions on the following 60 keV helium ions irradiation behavior of tungsten-tantalum alloy

摘要

W-5 %Ta specimens were irradiated by 800 keV Ar8+ ions at a fluence of 5.27 x 10(17) ions/m(2), then under exposure to 60 keV He2+ ions to a fluence of 1.04 x 10(22) ions/m(2). In this paper, an effect of Ar8+ ions pre-damaged on the following He2+ irradiation behavior of W-5 %Ta is reported. These results suggest that the size of large helium blisters on the surface of W-5 %Ta could be effectively reduced by the Ar8+ ions pre-damage. However, the helium retention was found to be systematically higher in the pre-damaged W-5 %Ta. Ar8+ ions pre-damage can greatly enhance the intensity of helium release peaks at low temperature ( 650 K). In addition, the hardness of undamaged and pre-damaged W-5 %Ta is approximately 7.3 and 9.8 GPa, respectively, indicating that the damage induced by Ar8+ ions irradiation has a significant effect on the mechanical properties of W-5 %Ta.