[2G17-22] Tungsten

[2G20] The influence of molybdenum on the helium emission rate from tungsten

*Kotaro Fukuda¹, Yuji Hatano¹ (1. University of Toyama)

Keywords:Tungsten, Molybdenum, Helium, Diffusion

Plasma-facing W is exposed to He ions in DT fusion reactors. Implantation of He results in blistering and surface exfoliation. Samin has performed computer simulation and reported He diffusivity in W decreases significantly by Mo addition. This result indicates He behavior can be controlled by alloying. Hence, the effects of Mo on He diffusion in W was experimentally examined by measuring He release rate at room temperature after exposure to glow discharge He plasma. The samples were the plates of W and W-1, 3.5 and 10 at.% Mo alloys. The He desorption rates from W-1 and 3.5Mo alloys were comparable with W sample, while W-10Mo alloy showed larger desorption rate. The observed tendency did not agree with the simulation result.