高能带电粒子的探测及其在人体组织中辐射效应的蒙特卡洛模拟

发布时间：2018-03-06 21:01

本文选题：高能带电粒子　切入点：蒙特卡洛模拟　出处：《苏州大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着航天事业的发展,载人飞船已逐步脱离地球轨道进入深层空间。研究数据表明,高能带电粒子是造成航天仪器失灵及宇航员辐射危险的主要原因之一。为了更好地探究空间辐射环境的组成及特性,对航天仪器的辐射加固、辐射损伤以及对航天员的辐射生物效应开展相关的实验活动,对高能带电粒子的探测及其在人体组织材料中辐射效应的蒙特卡洛模拟研究就显得尤为重要。本文基于苏州大学辐射应用技术团队研发的某型反符合△E-E粒子望远镜系统,利用蒙特卡洛程序包GEANT4对高能带电粒子在半导体、晶体探测器中的能量损失、射程径迹及在不同材料中的LET(Linear Energy Transfer)值进行了模拟研究,对不同能量、不同类型的高能粒子与探测器的能量沉积响应进行了对比分析。利用GEANT4提供的人体组织材料库类,对高能带电粒子在不同的人体组织材料中能量传输特性进行了模拟研究,计算了医用重离子在不同人体组织内的百分剂量分布。以Snyder头部模型为依据,构建了颅内肿瘤放疗模拟的人体头部模型,并对颅内肿瘤质子、重离子治疗的过程进行了相关模拟研究,利用研发的△E-E望远镜系统对重离子治疗过程中的碎裂反应产物进行了探测分析。研究结果显示,本文所研究的由固定厚度半导体与晶体探测器组成的△E-E望远镜系统,能够对8-175 MeV能量范围内的高能质子具有较好的能量响应关系,同时具有一定的粒子鉴别功能。增加晶体探测器的厚度可以提高探测器的能量测量范围,增大晶体探测器的宽度可以提高探测器的角度测量范围。同时此探测器能够对250 MeV/u的12C粒子轰击水靶过程中产生的次级带电粒子实现探测与鉴别功能,表明△E-E粒子望远镜可以用于碳离子治疗过程中的碎裂反应产物探测及剂量验证过程。
[Abstract]:With the development of spaceflight, manned spaceships have gradually stepped out of Earth orbit into deep space. High energy charged particles are one of the main causes of the failure of space instruments and the radiation danger of astronauts. In order to better explore the composition and characteristics of space radiation environment, the radiation reinforcement of space instruments is carried out. Radiation damage and the biological effects of radiation on astronauts, The Monte Carlo simulation of the detection of high energy charged particles and its radiation effects in human tissue materials is particularly important. This paper is based on an anti-E-E particle telescope system developed by the radiation application technology team of Suzhou University. The energy loss, range track and LET(Linear Energy transfer of charged particles in semiconductors and crystal detectors have been simulated by Monte Carlo package GEANT4. The energy deposition responses of different types of high energy particles and detectors are compared and analyzed. Using the human tissue material library provided by GEANT4, the energy transfer characteristics of high energy charged particles in different human tissue materials are simulated and studied. The percent dose distribution of medical heavy ions in different human tissues was calculated. Based on the Snyder head model, the human head model simulated by radiotherapy for intracranial tumors was constructed. The process of heavy ion therapy was simulated, and the fragmentation reaction products during heavy ion therapy were detected and analyzed by using the developed E-E telescope system. The results showed that, The E-E telescope system, which is composed of semiconductor and crystal detector with fixed thickness, has good energy response to high energy proton in the energy range of 8-175 MeV. At the same time, it has the function of particle discrimination. Increasing the thickness of the crystal detector can increase the energy measurement range of the detector. Increasing the width of the crystal detector can increase the angle measurement range of the detector. At the same time, the detector can detect and identify the secondary charged particles produced during the bombardment of 12C particles at 250 MeV/u. It is shown that E-E particle telescope can be used in the detection and dose verification of fragmentation reaction products in the course of carbon ion therapy.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R85

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