Effect of potassium doping and exposure temperature on the deuterium behavior in large-scale potassium-doped tungsten

In order to meet the needs of future fusion power plants in engineering application, a newly large-volume po-tassium-doped tungsten (WK) plate with a thickness of 15 mm was prepared by powder metallurgy and hot rolling technology. Pure tungsten (PW) as a comparison material was prepared using the same preparation process. To figure out the effect of K doping and exposure temperature on D retention and blistering morphology in WK and PW, the high-flux (-1022 m- 2 s- 1) and low energy (-50 eV) D plasma exposure with different temperatures (423, 473, 523 and 573 K) was performed. The results show that there is serious surface blistering in both PW and WK at all exposure temperatures and PW forms D blisters larger in size but smaller in number compared with WK. The D retention in PW is significantly lower than that in WK at all exposure temperatures. Moreover, the evolution of D blisters and retention in WK is more sensitive to exposure temperature compared to PW. The effects of K doping and exposure temperature on blistering morphology and D retention were analyzed and discussed in detail.