Deuterium retention in Toughened, Fine-Grained Recrystallized Tungsten

Deuterium retention in Toughened, Fine-Grained Recrystallized W (TFGR W-1.1 wt%TiC) was studied, compared to pure W. D implantation was performed to a fluence of 1 × 1024 m−2 at temperatures of 473–873 K, followed by TDS. It was found that D retention in TFGR W is higher than in pure W at all irradiation temperatures. Namely, at 673 K, D retention in TFGR W is six times higher than pure W. TDS spectrum of TFGR W irradiated at 573 K has a large peak around ∼700 K with small shoulder up to ∼1100 K. In the case of D + He simultaneous irradiation, D retention is about 30% lower than for pure D. In addition, plasma exposure experiment was also conducted in TEXTOR, followed by NRA. Higher retention in TFGR W-1.1 wt%TiC could be attributed to high grain boundary diffusion (then trapping deeper into the bulk) and formation of TiD2