高能伽玛相机探测量子效率的蒙特卡罗模拟  

Monte Carlo simulation for detector quantum efficiency in high-energy gamma camera

作　　者：许海波[1] 郑娜[1] 陈朝斌[1] 

机构地区：[1]北京应用物理与计算数学研究所,北京100094

出　　处：《强激光与粒子束》2013年第10期2734-2738,共5页High Power Laser and Particle Beams

基　　金：国家自然科学基金委员会与中国工程物理研究院联合基金重点项目(11176001);中国工程物理研究院科学技术发展基金重点项目(2012A0202006)

摘　　要：探测量子效率(DQE)可被用来精确描述图像噪声通过成像系统的传播特性。根据级联理论,简洁得出了零频噪声传播情况下成像系统的DQE表达式。采用蒙特卡罗程序MCNP计算了高能X射线的硬化能谱在六种常用闪烁晶体中的能量沉积分布以及高能伽玛相机的DQE,分析了闪烁晶体的材料和厚度对DQE的影响。模拟结果表明,高密度、高原子序数是影响DQE的主要因素,在同样厚度下,LuAP和LSO转换屏的探测量子效率最高。The detector quantum efficiency （DQE） is used to describe the propagation of the noise in the imaging system. According to the cascade theory, the DQE of the high-energy gamma camera depends on the gain of the scintillator and the CCD, and the absorbed energy deposition in the scintillator. In this paper, the Monte Carlo code MCNP is employed to simulate the dis- tribution of the energy deposition for X-ray through different scintillators. The DQE of the high-energy gamma camera for differ- ent scintillator with different thickness is calculated and analysed. From the simulation, it can be seen that the DQE is correlative with the density and the atomic number of the scintillator. The DQEs of the LuAP and LSO are much bigger than other scintilla- tor with the same thickness. The method presented in this paper can be used to the design of the high-energy gamma camera.

关 键 词：闪烁晶体 Swank因子 能量沉积 探测量子效率 蒙特卡罗方法 

分 类 号：O434.12[机械工程—光学工程] O571.33[理学—光学]