Nonproportionality and energy resolution of a LaCl3:10% Ce3+ scintillation crystal

The electron and photon response of an aluminum canned LaCl₃:10% Ce³⁺ crystal were measured using the Compton coincidence technique (CCT). The LaCl₃:10% Ce³⁺ electron response increases from 7 keV to 30 keV by about 10%. Above 30 keV, the electron response levels, i.e., it is flat within 5%. The Monte Carlo N particle code (MCNP4C) was used in the photon response calculation. The calculated theoretical photon response is in good agreement with the measured photon response. An energy resolution (full width at half maximum over the peak position) of 4.2±0.5% was observed for the 662 keV full absorption peak. The energy resolution as function of photon energy exhibits a linear relationship with the inverse square root of the energy. The step like curves of NaI(Tl) with a semi plateau in the energy range between 100 and 500 keV have not been observed for LaCl₃:10% Ce³⁺.