Energy calibration of gamma spectra in plastic scintillators using Compton kinematics

This paper describes a simple and practicable method for assigning energy values to gamma-ray pulse-height distributions measured with polyvinyl toluene (PVT) based detectors. It is based upon the characteristic shape of simulated spectra in the region of maximum energy deposition resulting from a single Compton scattering. The validity of this method is demonstrated by applying it to a set of measured NaI(Tl) spectra, and comparing those results to the standard photopeak method of calibrating the same spectra. The method is then applied to a set of measured PVT spectra. It can now be applied to calibration of fielded PVT detectors using two selected gamma-ray sources, which was the initial motivation for this study.