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 liqui d scintillator surrounded by an NE115 plastic scintillator to measure high energy neutron spectra accurately in a charged-particle mixed fie ld. Differences in the decay time constants of light outputs from the two scintillators make it possible to separate charged-particle-induce d and neutron-induced pulses. Experiments were carried out at the RIKE N and at the NIRS cyclotrons. This detector was found to be able to di scriminate neutron and gamma-ray events from external-proton events. T his detector will be useful to measure high energy neutron in space.