Chagren S, Tekaya M Ben, Reguigui N, Gharbi F
Centre National des Sciences et Technologies Nucleairés 2020 Pole Technologique de Sidi Thabet, Tunisia.
Centre National des Sciences et Technologies Nucleairés 2020 Pole Technologique de Sidi Thabet, Tunisia.
Appl Radiat Isot. 2016 Jan;107:359-365. doi: 10.1016/j.apradiso.2015.11.026. Epub 2015 Nov 17.
In this work we apply the GEANT4 code of CERN to calculate the peak efficiency in High Pure Germanium (HPGe) gamma spectrometry using three different procedures. The first is a direct calculation. The second corresponds to the usual case of efficiency transfer between two different configurations at constant emission energy assuming a reference point detection configuration and the third, a new procedure, consists on the transfer of the peak efficiency between two detection configurations emitting the gamma ray in different energies assuming a "virtual" reference point detection configuration. No pre-optimization of the detector geometrical characteristics was performed before the transfer to test the ability of the efficiency transfer to reduce the effect of the ignorance on their real magnitude on the quality of the transferred efficiency. The obtained and measured efficiencies were found in good agreement for the two investigated methods of efficiency transfer. The obtained agreement proves that Monte Carlo method and especially the GEANT4 code constitute an efficient tool to obtain accurate detection efficiency values. The second investigated efficiency transfer procedure is useful to calibrate the HPGe gamma detector for any emission energy value for a voluminous source using one point source detection efficiency emitting in a different energy as a reference efficiency. The calculations preformed in this work were applied to the measurement exercise of the EUROMET428 project. A measurement exercise where an evaluation of the full energy peak efficiencies in the energy range 60-2000 keV for a typical coaxial p-type HpGe detector and several types of source configuration: point sources located at various distances from the detector and a cylindrical box containing three matrices was performed.
在这项工作中，我们应用欧洲核子研究组织（CERN）的GEANT4代码，通过三种不同的程序来计算高纯锗（HPGe）γ能谱中的峰效率。第一种是直接计算。第二种对应于在恒定发射能量下，假设参考点探测配置，在两种不同配置之间进行效率传递的常见情况，第三种是一种新程序，它基于假设一个“虚拟”参考点探测配置，在发射不同能量γ射线的两种探测配置之间传递峰效率。在进行传递之前，未对探测器的几何特性进行预优化，以测试效率传递减少因对其实际大小的无知而对传递效率质量产生影响的能力。对于所研究的两种效率传递方法，发现获得的效率与测量的效率吻合良好。所获得的一致性证明，蒙特卡罗方法，尤其是GEANT4代码，构成了获得准确探测效率值的有效工具。所研究的第二种效率传递程序对于使用在不同能量下发射的一个点源探测效率作为参考效率，来校准用于大量源的任何发射能量值的HPGeγ探测器很有用。在这项工作中进行的计算应用于EUROMET428项目的测量工作。在该测量工作中，对典型的同轴p型HpGe探测器在60 - 2000 keV能量范围内的全能峰效率进行了评估，涉及几种源配置：位于距探测器不同距离处的点源以及一个装有三种基质的圆柱形盒子。
