Tritium yields in all six Large Helical Device deuterium experiment campaigns, or 41 064 discharges, have been numerically estimated. Usually, tritium yields are estimated from neutron yields by assuming that they are the same. In present fusion devices, this assumption is inaccurate because a fusion reaction between thermal-deuterons and fast-deuterons is dominant. In this paper, the energy distribution of fast-deuterons injected by neutral beam injectors is taken into account for the estimation of the ratio of the tritium yields to the neutron yields, . By integrated simulation, the is approximately 0.94 in each campaign. Because assumptions applied in the simulation aim to avoid under-estimation of the tritium yields compared to the actual value, the should be .
This paper estimates the tritium yields in all LHD deuterium experiments, accounting for the fusion reaction between thermal and fast deuterons. The ratio of tritium to neutron yields is found to be around 0.94, suggesting the tritium yields may be higher than previously assumed.