充气反冲核谱仪焦平面探测阵列的GEANT4模拟

GEANT4 Simulation of the Focal Plane Detection Array of Gas-filled Recoil Separator

摘要: 充气反冲核谱仪(SHANS)是目前国内合成缺中子锕系新核素、研究重核素α衰变性质的重要实验装置。为进一步提高焦平面探测阵列对重核素α衰变粒子和射线的探测效率，计划对现有探测装置进行升级。本文的主要工作是采用基于蒙特卡罗方法的GEANT4软件对现有的谱仪探测器阵列进行模拟，并与实验测量数据进行比较，以验证程序的准确性。结果表明，新探测系统对α衰变粒子的探测效率可达到88%左右，对能量在1 MeV的\gamma射线全能峰的探测效率约为7%。

Abstract: The gas-filled recoil nuclear separator SHANS(Spectrometer for Heavy Atoms and Nuclear Structure) is an important experimental device for synthesing new neutron-deficient actinide nuclides and studying α decay properties of heavy nuclides in China. In order to further improve the detective efficiency of the focal plane detector array for heavy nuclide α decay particles and \gamma rays, we plan to upgrade the existing detection instrument. The main work of this paper is to simulate the existing detector array by using the GEANT4 software based on Monte Carlo method. In order to verify the accuracy of the program, the simulation was compared with the experimental data. The results show that the detective efficiency of the new detector system for α decay particles is about 88%, and the detective efficiency for \gamma rays with an energy of 1 MeV is about 7%.