Abstract

The optimization of measurement of environmental samples is achieved by putting the sample closer to the detector to increase the full-energy peak efficiency, which leads to decrease of the detection limit. The present work inspects the utilization of Geant4 simulation for a NaI cubic scintillation detector with a cavity using two tracks. The radionuclide option includes coincidence summing, and the monoenergetic option is summing free coincidence. The ratio between the monoenergetic to redionuclide options gives the coincidence summing correction factors. In the experiments a gamma-ray aqueous source containing the radionuclide ¹⁵²Eu covering the range from 121 to 1408 keV was used. Comparing the monoenergetic option for calculating the full-energy peak efficiency and the corrected experimental efficiency, the values are in agreement.

摘要

环境样品测量的优化是通过将样品靠近检测器来提高全能峰效率，从而降低检测限。目前的工作检查了 Geant4 模拟对具有使用两个轨道的腔的 NaI 立方闪烁探测器的利用。放射性核素选项包括重合求和，单能选项包括自由重合求和。单能与再核素选项之间的比率给出了重合求和校正因子。在实验中，含有放射性核素¹⁵²的伽马射线水源使用了覆盖 121 至 1408 keV 范围的 Eu。比较计算全能峰值效率和校正实验效率的单能选项，值是一致的。