Development of compound neutron dose meter

Hashimoto, Makoto  ; Torii, Tatsuo  ; Ando, Hideki

The new radiation weighting factors for neutron are introduced in ICRP 1990 Recommendations instead of the former quality factor. The contribution of intermediate energy neutron to the dose estimated with the new factors is more serious than with the former factors. Therefore, it indicates that the neutron dose evaluated by the former factors sometimes underestimates the dose evaluated by the new factors. Accordingly, to develop the neutron dose meter adjusted to the new recommendations, the new neutron detector has been cxperimented. In this study, instead of moderated detectors usually used as a neutron dose rate meter, the compound detector based on the multidetector method was employed. To understand the characteristic of this detector, we simulated the energy response and carried out the characteristic cxamination with neutron sources and accelerators. As a result of energy response simulation, in the region of interest, it can apply the multidetector method. As a result of characteristic examination, the detector can be used for measuring the neutron dose. Furthermore, in processes of the examination, this detector can discriminate the average energy of neutrons of Am-Be from that of Pu-Be. It is very sensitive to the neutron cnergy difference at intermediate energy. In future, it will be made improvement to make more practical dose estimation, and it will be made investigation to apply the ability of energy resolution.