Measurements of the Source Term for Annular Blanket Experiment with a Line Source: Phase IIIA of JAERI/USDOE Collaborative Program on Fusion Neutronics

Abstract

A pseudo line DT neutron source has been realized by moving an experimental assembly with respect to a point DT source in the Phase-III experiment of JAERI/USDOE collaborative program on fusion blanket neutronics. In order to examine characteristics of the pseudo-line source made by two types of operational modes, source term experiments were carried out. Neutron flux distribution above 10 MeV was measured by NE213 scintillator with stepwise source mode. The reaction rate distributions were also measured by activation foil technique with continuous source mode. The measured distributions were almost flat over central 1 m region of the simulated line source and agreed relatively with a simple calculation assuming the ideal line source. From these experimental results it was concluded that both modes worked successfully to obtain the pseudo-line source and could simulate well neutron flux distribution emitted from a finite length line source with small influence of reaction kinematics and target structure.