Neutron detection using conversion layers and YAP:Ce and YAG:Ce crystals

Abstract

The work deals with the detection of thermal neutrons using a conversion layer of LiF on YAP:Ce and YAG:Ce scintillation crystals of various sizes. Enriched LiF (95 at. % 6Li) in the form of a mixture with 5 % polyvinyl alcohol was deposited on the crystal face by spraying it in a thin layer. The252Cf isotope with paraffin moderation and lead shielding was used as a neutron source. The detection is based on the nuclear reaction of6Li with the neutron. The conversion leads to emitting an alpha particle and triton according to the scheme6Li (n, α)3H + + 4.5 MeV which are detected by the scintillation crystal. Due to gamma ray interaction, the optimum thickness of the crystal was estimated to 70 μm.