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基于ICRU模型的辐射剂量计算
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Abstract:
不同组织器官辐射敏感性不同，且处于人体不同深度位置，因而复杂的空间辐射环境对各组织器官的危害不同。宽能谱质子是空间主要辐射粒子，获得质子能量和组织器官吸收剂量的对应关系对于飞行前辐射风险评估十分必要。国际辐射单位与测量委员会(ICRU)设定的组织等效模型相对人体模型质量小、形状规则，从任务实际出发更适于空间辐射监测与评估。本工作通过仿真计算建立了ICRU模型，分析了不同能量质子及γ射线与ICRU模型的相互作用过程，模拟了不同深度人体组织中探测到的吸收剂量，建立了基于ICRU模型的剂量监测校准和剂量预估仿真计算体系。
Tissues and organs which show various radiosensitivity are in the specific depths of human body, so they suffer different levels of damage caused by the complex space radiation. Proton with wide spectrum is the main particle type in space and it is necessary to acquire the relationship between the energy of proton and the absorbed dose of tissues and organs for radiation-risk evaluation before space missions. The tissue-equivalent model recommended by International Commission on Radiation Units and Measurements (ICRU) is light and regular compared to the phantoms so that it is more suitable in practice for space radiation monitoring and evaluation. The ICRU model was established through simulation in this work. The mechanism of the interaction between ICRU model and protons/gamma-rays with different energies was analyzed and the absorbed dose of tissues and organs in the different depths of human body was calculated. The calibration system for dose monitoring based on ICRU model and the calculation system for dose evaluation was established.
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