Dual discrimination of fast neutrons from strong γ noise using organic single-crystal scintillator

Summary

Extensive fast-neutron-based applications and radiation monitoring are inseparable from fast-neutron detection, but the interference of accompanying γ rays requires fast-neutron/γ discrimination (FNGD). Organic single-crystal scintillators (OSCSs) generate fast-neutron-induced delayed fluorescence and γ-induced prompt fluorescence (PF), which can be discriminated by one-step pulse-shape discrimination (PSD). However, PSD cannot identify neutron-induced PF, introducing errors in neutron counting. Here, we report a dual-discrimination approach for accurate fast-neutron detection using γ-ray-insensitive tetraphenylethylene (TPE). In contrast to previous OSCSs, TPE realizes FNGD by PSD and pulse-height discrimination (PHD), since it simultaneously exhibits disparities in shape and pulse height under neutron and γ irradiation. PHD enables secondary FNGD from PF, significantly increasing neutron counts. The improved FNGD method based on TPE reveals a high figure of merit (FoM = 2.4) and count rate of neutrons (35.5%). Our research provides new ideas and available materials for high-efficiency FNGD, promoting the applications of fast neutrons.