Estimation of the Tritium Yields in Deuterium Fusion Plasmas Considering the Fast-Ion Velocity Distribution Function

Tritium yields due to the deuterium-deuterium fusion reaction during the 22nd LHD experiment campaign are numerically estimated. As usual, the total tritium yields are assumed to be the same total neutron yields. In the Large Helical Device (LHD), however, it is considered that fusion reactivity of the D(d,p)T branch is lower than that of the D(d,n)(3) He one because the fusion reaction between a fast-deuteron and a thermal deuteron is dominant. By integrated simulation, considering the velocity distribution function of fast-deuteron, the ratio of the tritium yields to the neutron yields is estimated to be Y-t/Y-n similar to 0.936. From the assumptions applied in the simulation, it is expected that this value should be still an over-estimation rather than the actual value. (C) 2022 The Japan Society of Plasma Science and Nuclear Fusion Research