Measurement of the Number of Photoelectrons per MeV for Neutron Detectors

Abstract

The light gains of a detector system (photomultiplier tube and scintillator) is characterized by the number of photoelectrons produced per unit of energy (usually MeV). In this study, the results of light gain tests for 10 Hamamatsu R11833 model photomultiplier tubes are shown. Various radioactive sources were used in conjunction with the EJ309 liquid scintillator to determine the light gain. The number of photoelectrons produced per unit energy was determined by comparing the size of the signal generated by the photons produced by photomultiplier tube during the scintillation process using radioactive sources and the size of the signal generated when a single photoelectron was produced by the photomultiplier tube. The test results show that the performances of the photomultiplier tubes are sufficient for neutron detector arrays used in experiments with radioactive ion beams. The supply voltage of the photomultiplier tubes must be changed to achieve similar light gains.