Optimization of the LaBr₃ detector model using differential evolution algorithms

In gamma-ray spectrometry, computational detector model allows determining absolute detector efficiency for non-standard sources with varying chemical compositions in the absence of volumetric calibration standards. This study focuses on developing a computational model of a LaBr₃(Ce) 1.5" × 1.5″ scintillation detector based on characterization data. The detector was characterized using ¹³⁷Cs and ¹⁵²Eu point calibration sources placed at various positions relative to the detector cap. Modeling was performed using the MCNP6 code based on the Monte Carlo method. The initial modeling results revealed deviations between the calculated and experimental detector responses, which required model optimization. Optimization of the detector parameters was carried out using differential evolution algorithms. To verify the optimized LaBr₃ model, studies were conducted with a volumetric KCl source. The deviations between the calculated and experimental results fell within the error limits.