Discrimination of particles by the scintillation pulse shape (in the electron energy range of 0.5–4.0 MeV) using the zero-crossing method

Abstract

The ratios of the fast to slow components of scintillation pulses produced by neutrons and γ rays have been calculated on the basis of experimental data for several energies in the range of 0.5-4.0 MeV of the electron equivalent. The procedure for discriminating between neutrons and γ rays by measuring the zero-crossing time of a bipolar pulse formed by RC circuits has been simulated for organic scintillators using the Monte Carlo method in the range of 0.012-4.000 MeV of the electron equivalent. It is shown that pulse shape discrimination of particles based on the zero-crossing technique allows rejection of γ-ray background down to a level of 10-4 at particle energies of >100 keV of the electron equivalent (for energies of <50 keV, the γ-ray background is suppressed to a level of 10^-1- 10^-2 and this technique becomes ineffective in principle).