Energy calibration of organic scintillation detectors by using a two-dimensional broad mapping method

A two-dimensional broad mapping method using Compton coincidences was investigated in this study for energy calibration of organic scintillation detectors. The calibration system consisted of an organic scintillation detector detecting the Compton recoil electrons and a HPGe detector measuring the Compton scatter photons in coincidence. A 2" (length) × 2" (diameter) NE213 and a 5" (length) × 5" (diameter) EJ301 liquid scintillation detectors were used to investigate the size-dependent effect of multiple scattering within the detector. The difference between measurements using collimated and uncollimated γ-ray sources were also studied. Our results show that the relationship of E_H, E_H/2 and E_c depends on the energy resolution, which includes the factor of detector size, and incident photon energy. The methodology used in this study is capable of providing an accurate, relatively quick and reliable calibration over a broad range of electron energies for organic scintillation detectors by using uncollimated γ-ray sources.