Nonproportionality of electron response using CCT: Plastic scintillator

The scintillation response of a plastic scintillator (NE102) has been characterized using compton coincidence technique. The coincidence technique allowed detection of nearly monoenergetic internal electrons resulting from the scattering of incident 662 keV γ-rays within a primary NE102 detector. Scattered γ-rays were detected using a secondary NaI(Tl) detector in a coincidence mode. The electron response nonproportionality of NE102 plastic scintillator was measured using this technique for electron energies ranging from 28 to 436 keV, by varying the scattering angle. The NE102 showed a good proportionality of light yield within 3% at energies between 90 and 436 keV. Below 90 keV, the light yield decreases by about 20% upon lowering the electron energy to 28 keV. The electron energy resolution of NE102 was also measured using this technique in the energy range from 68 to 436 keV. It has been found that the energy resolution varies from 25.2% at 68 keV to 11.8% at 436 keV.