Neutron Spectrometer with Capture-Gated Liquid Scintillator

Abstract

We have developed a capture-gated neutron spectrometer with a liquid scintillator and a lithium glass scintillator. The neutron-scattering signals from the liquid scintillator and the neutron-capture signals from the lithium glass scintillator were processed and collected separately by using a digital pulse processing technique. Neutron and gamma separation was performed using a pulse shape discrimination technique, which showed a 98 % selection capability above a neutron energy of 1 MeV. The correlation between the incident neutron energy and analogue-to-digital converter (ADC) values of the liquid scintillation counter was obtained by using a time-of-flight method to measure the neutrons emitted from a 252 Cf source. The correlation function of the ADC values and the neutron energy allowed us to determine the neutron energy by using only the ADC values of the liquid scintillation detector for capture-gated events. This work shows that the capture-gated neutron spectrometer can be used in neutron dosimetry.