A DATABASE OF FREQUENCY DISTRIBUTIONS OF ENERGY DEPOSITIONS IN SMALL-SIZE TARGETS BY ELECTRONS AND IONS
A DATABASE OF FREQUENCY DISTRIBUTIONS OF ENERGY DEPOSITIONS IN SMALL-SIZE TARGETS BY ELECTRONS AND IONS
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DOI：
10.1093/rpd/ncq396
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发表时间：
2011-02-01
影响因子：
1
通讯作者：
Pinsky, L.
中科院分区：
文献类型：
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作者：
Nikjoo, H.;Uehara, S.;Pinsky, L.
线性能量传递（LET）是一个平均量，无法显示目标体积中辐射轨迹相互作用的随机性。因此，定义了微剂量分布来克服 LET 的缺点。在本文中，报告了电子、质子、α 粒子和碳离子在纳米尺寸目标（直径 1-100 nm）和 1 mm 直径无壁 TEPC 中能量沉积的频率分布的模型计算。尺寸与生物分子相似的小尺寸目标中能量沉积的频率分布对于 DNA 损伤的建模和计算非常有用。蒙特卡罗径迹结构代码KURBUC和PITS99用于生成初级电子10 eV至1 MeV和离子1 keV μ m(-1)至300 MeV μ m(-1)能量的径迹。获得了在用 1 Gy 的给定辐射照射的单位密度水中随机放置的直径为 1-100 nm 的体积中能量沉积的绝对频率分布。提供了能量沉积频率和微剂量测定量的数据，包括平均线能、剂量平均线能、频率平均比能和剂量平均比能。这项工作中提出的建模和计算对于表征生物物理研究和放射治疗中的辐射束质量非常有用。
Linear energy transfer ( LET) is an average quantity, which cannot display the stochastics of the interactions of radiation tracks in the target volume. For this reason, microdosimetry distributions have been defined to overcome the LET shortcomings. In this paper, model calculations of frequency distributions for energy depositions in nanometre size targets, diameters 1-100 nm, and for a 1 mm diameter wall-less TEPC, for electrons, protons, alpha particles and carbon ions are reported. Frequency distributions for energy depositions in small-size targets with dimensions similar to those of biological molecules are useful for modelling and calculations of DNA damage. Monte Carlo track structure codes KURBUC and PITS99 were used to generate tracks of primary electrons 10 eV to 1 MeV, and ions 1 keV mu m(-1) to 300 MeV mu m(-1) energies. Distribution of absolute frequencies of energy depositions in volumes with diameters of 1-100 nm randomly positioned in unit density water irradiated with 1 Gy of the given radiation was obtained. Data are presented for frequency of energy depositions and microdosimetry quantities including mean lineal energy, dose mean lineal energy, frequency mean specific energy and dose mean specific energy. The modelling and calculations presented in this work are useful for characterisation of the quality of radiation beam in biophysical studies and in radiation therapy.