Calculation of scintillation properties of Ø1″×1″ of the lanthanum bromide scintillation detector using MCNP simulation and experiment

Abstract

The purpose of this study is to develop a model for gamma spectroscopy for calculation of full width at half maximum (FWHM), energy resolution and full-energy peak absolute detection efficiency of Ø1″×1″ of the lanthanum bromide LaBr3 (Ce) detector crystal. For this purpose, a complete detector model was developed for Monte Carlo N-Particle (MCNP) transport code. In MCNP simulation, F8 tally was used as it gives the energy distribution of pulses created in the detector. Whenever incident gamma ray enters into detector volume, due to interactions short pulses are produced inside the detector volume. The pulse height spectra of various gamma sources were obtained, which were used to calculate different scintillator properties of our interest. In the simulation, the distance from the source to the detector face was varied to see the effects on scintillation properties of the detector crystal. The detector crystal offers the energy resolution of 3.455% and the FWHM of 22.81 KeV when gamma source Cs137 (662 KeV) was used. As we increased the incident gamma ray energy, the FWHM of the detector crystal increased, while the energy resolution and absolute detection efficiency of the detector crystal decreased. The scintillation properties of Ø1″×1″ of the LaBr3 (Ce) detector crystal were studied experimentally. In our case, it was observed that experimental and simulation results coincided. This proves that the detector model we built for gamma spectroscopy in MC transport code is accurate.