Dynamical saturated concentration of deuterium in a beryllium foil studied by low energy D(d,p)T reaction

Deuterium (D) retention is related to the fuel balance and operational safety of a fusion reactor. A dynamical saturated deuterium concentration during D implantation was studied by a low energy D(d,p)T reaction. 20 keV/D deuterium ions D3+ with a flux of 3.0 × 1014 D/(cm2 s) was implanted into a beryllium foil until a saturation state was achieved, and the proton yield was recorded as a function of fluence during implantation. A 75 keV D+ beam with a current of 0.6 μA was also used to monitor the change of D concentration in the target, not only at several fluences during implantation, but also at several storage times after the implantation terminated. The saturated value of nD/nBe is (20 ± 2) at.% at a fluence of ∼1019 D/cm2 in the target temperature between 300 and 340 K. The result indicates that the static deuterium concentration is 8% lower than the dynamical saturated concentration.