A dual‐scintillator time‐of‐flight spectrometer for secondary fast neutrons in proton radiotherapy

In order to measure the energy spectra of secondary neutrons in proton and heavy-ion radiotherapy, a neutron spectrometer has been developed. In this paper, two organic scintillation detectors combined with photomultiplier tubes were used to form a dual-scintillator time-of-flight spectrometer. The performance of this spectrometer was tested with a DT neutron generator, and the detection efficiency of each detector as well as the spectrometer were simulated by Geant4 toolkit. It’s shown that the time resolution of the spectrometer is 0.797 ns with an energy resolution of 26.4% for neutrons with an energy of 14 MeV at a flight distances over 150 cm.