组织等效介质中正离子径迹周围剂量分布特性研究  

Dose distribution around ion track in tissue equivalent material

作　　者：张文仲[1] 郭勇[2] 骆亿生[2] 

机构地区：[1]北京防化指挥工程学院,102205 [2]军事医学科学院放射与辐射医学研究所

出　　处：《中华放射医学与防护杂志》2007年第3期282-285,共4页Chinese Journal of Radiological Medicine and Protection

基　　金：志谢 在课题的前期计算中,中国原子能科学研究院卓益忠研究员提供了用于计算正离子在介质中能量沉积的M0CA程序版本-M0CA15,在程序调试、运行期间,曹天光博士给予了具体帮助

摘　　要：目的探讨正离子在人体组织（或组织等效介质）中能量沉积的微观特性。方法在对人体组织材料进行分析的基础上,确定了密度为1g/cm^3水蒸汽作为组织等效材料的合理性,利用MC粒子输运技术模拟了质子在介质中的微观行为。通过对计算所得数据进行系统分析,得出正离子在组织等效材料中能量沉积微观特性的一些规律与特点。结果在介质中正离子除使原子激发损失能量之外,还会通过电离的方式,把其能量交给次级电子,最后由电子完成其能量沉积过程。所以,正离子在介质中发生能量沉积时,大部分能量沉积在径迹芯上,次级电子主要在径迹芯以外发生能量沉积,从而在介质中形成特定的剂量分布形式。结论正离子在介质中产生的剂量分布研究对于探讨辐射生物效应具有重大意义。Objective To study the energy deposition micro-specialty of ions in body-tissue or tissue equivalent material（TEM）. Methods The water vapor was determined as the tissue equivalent material, based on the analysis to the body-tissue, and Monte Carlo method was used to simulate the behavior of proton in the tissue equivalent material. Some features of the energy deposition micro-specialty of ion in tissue equivalent material were obtained through the analysis to the data from calculation. Results The ion will give the energy by the way of excitation and ionization in material, then the secondary electrons will be generated in the progress of ionization, these electron will finished ions energy deposition progress. When ions deposited their energy, large amount energy will be in the core of tracks, and secondary electrons will devote its＇ energy around ion track, the ion dose distribution is then formed in TEM. Conclusions To know biological effects of radiation, the research to dose distribution of ions is of importance（significance）.

关 键 词：正离子 MC方法 组织等效材料 径迹结构 剂量分布 

分 类 号：R686[医药卫生—骨科学]