Annular Blanket Experiment Using a Line DT Neutron Source: Phase IIIA of the JAERI/USDOE Collaborative Program on Fusion Neutronics

Neutronics experiments for an annular blanket system have been performed using a simulated line DT neutron source. The line source was simulated by moving point source in which the annular blanket was oscillated relatively on the axis of the DT neutron target. The measurements were performed in both ways of continuous and stepwise motions. The former was applied to heavy irradiation experiments such as the foil activation method for reaction rate and Li₂O pellet technique for tritium production rate (TPR). The latter was to on-line methods such as NE213 and Li-glass scintillators for spectrum and TPR of ⁶Li and ⁷Li. Especially the latter case provides contribution of neutrons generated at each point on the line source to the reaction at the detector position. This corresponds to an importance distribution at the center axis of the annular system and can be compared to the calculated adjoint flux at the source positions.