新型康普顿γ相机模拟设计

The Design and Simulation of a New Multilayer Compton Camera

设计了一种具有两种工作模式的三层康普顿相机,两种工作模式分别利用了一次和两次康普顿散射,提高系统探测效率和能够同时探测不同能量的γ源的效果。利用Geant4和python对系统进行了物理层面和电子学层面的模拟,获取一个事件中每层探测器的位置和沉积能量信息。利用模拟数据和成像算法,得到了不同位置,不同能量γ源的成像效果图。模拟结果说明,成像系统最佳角分辨能够达到6.5°左右,能够通过一次测量,对不同能量的源进行同时成像;系统相较于仅利用一次散射原理的成像方法,相同条件下本征探测效率有31.2%的提升。

A 3-layer Compton camera was designed which has 2 work modes using one and two Compton scattering events respectively.This camera could detect multi-energy gamma sources at one measurement with a relatively high detection efficiency.A simulation of this camera,which simulated from a gamma particle injecting to the camera to the electronic signal produced by the camera,is applied by the Geant4 toolkits and python,which could record the energy information and positions of the interaction in each layer.A Maximum Likelihood Estimation Method algorithm is designed for the imaging.With the interaction information and the algorithm,the imaging of source with different energy and positions were established.The simulation results shows the angular resolution of the camera is nearly 6.3°,and the camera is capable of locating sources with different energy and locations in just one measurement.The detection efficiency is 31.2%larger than the camera just using one Compton scattering events in the same condition.