Development of the Environmental Neutron Detection System

Kume, Kyo*; Otani, Nobuo*

Environmental neutron detection system is proposed. The main goal of this system was set to detect fast and thermal neutrons with the identical detector setup without degraders. A detector setuup for thermal neutron counting in prebious years, was developed first. Feasible study of this detector system for fast neutron counting was done, with help of Monte Carlo simulation and analysis of experiments with both a neutron source and neutron beam at an accelerator facility. In addition, B doped plastic intillator was studied for measurement of environmental neutrons. This was done through experiments with an Am-Be neutron source, with help of Monte Carlo simulation. In the meantime, possibility of the use of inorganic scintillators in neutron counting was verified, to solve the problems occuring at the long term use of the organic liquid scintillators. The detectors checked were BGO, GSO, and Nal. BGO was shown that it has little possibility for use at neutron measurement, while GSO and Nal were shown that these detectors have trivial sensitivity in neutron measurement.