A Setup for Studying Interactions of Fast Neutrons and Light Nuclei with an Electron−Positron Pair Spectrometer

Abstract An experimental setup has been developed to study interaction between fast neutrons with an energy above 1 MeV and low- Z nuclei with the emission of a 3 H or 4 He nucleus and an electron−positron pair. Its components are a position-sensitive neutron detector with a layer of nuclei under study and proportional chamber with sensitive dimensions of 50 × 50 mm 2 , two position-sensitive silicon detectors with sensitive dimensions of 64 × 64 mm 2 , and two scintillation detectors based on NaI crystals with a diameter of 42 mm, a height of 46 mm, and an energy resolution of ~4.5% for electrons. It is possible to study rare intranuclear processes with the emission of internal-conversion electron−positron pairs by performing spatial reconstruction of events and measuring the energy and exit angle of an electron and a positron.