Updated Characterization of Cerium(III) Bromide Scintillation Detector

The material cerium(III) bromide (CeBr3) was relatively recently developed for use as a scintillator. The purpose of this paper is to provide a characterization of this new material, as well as a characterization of the more common sodium iodide (NaI) for comparison. The two materials will be compared in terms of three performance metrics, including energy linearity, energy resolution and intrinsic efficiency. Ideally there will be a linear relationship between the intensity of the light output from the material and the energy deposited in the scintillator by an incoming particle. However, it has frequently been observed that many scintillator materials demonstrate some nonlinearity, particularly when detecting particles at relatively low energy levels. This quality can be examined by computing a trend of channel numbers certain peaks were binned in on an MCA versus the corresponding known energy level of the gamma from the source, and determining the linearity of this trend. Another important property of scintillators is energy resolution, and CeBr3 has been previously shown to exhibit improved resolution in comparison to NaI. This quality can be shown by plotting a trend of the full width at half maximum of the peak versus the energy of the incoming particle. Resolution vs. energy in scintillators typically follows a power law; a power of 0.5 in energy is the statistical limit for scintillator resolution. Finally, the materials will be compared in terms of their intrinsic efficiencies. This value can be calculated by taking the area under the peak for each energy level and dividing out both the geometric efficiency of the experimental setup and the strength of the corresponding source. All of the values needed to study these characteristics will be calculated using a curve fitting code designed to fit the peaks provided by the MCA data. In previous studies CeBr3 has shown higher luminosity than NaI, as well as a shorter fluorescence time. This will most likely result in improved performance metrics, especially improved resolution. These characteristics of CeBr3 will show its utility in numerous applications demanding medium resolution, including those involving high count rate environments.