Development of a phoswich detector to detect neutrons and charged particles for space application

We have developed a new phoswich detector consisting of an NE213 liquid scintillator surrounded by an NE115 plastic scintillator to measure high energy neutron spectra accurately in a charged-particle mixed field. Differences in the decay time constants of light outputs from the two scintillators make it possible to separate charged-particle-induced and neutron-induced pulses. Experiments were carried out at the RIKEN and at the NIRS cyclotrons. This detector was found to be able to discriminate neutron and gamma-ray events from external-proton events. This detector will be useful to measure high energy neutrons in space.