Nikjoo H, Uehara S, Pinsky L, Cucinotta Francis A
USRA, NASA Johnson Space Center, Houston, Texas 77058, USA.
Radiat Prot Dosimetry. 2007;126(1-4):512-8. doi: 10.1093/rpd/ncm103. Epub 2007 May 19.
Space activities in earth orbit or in deep space pose challenges to the estimation of risk factors for both astronauts and instrumentation. In space, risk from exposure to ionising radiation is one of the main factors limiting manned space exploration. Therefore, characterising the radiation environment in terms of the types of radiations and the quantity of radiation that the astronauts are exposed to is of critical importance in planning space missions. In this paper, calculations of the response of TEPC to protons and carbon ions were reported. The calculations have been carried out using Monte Carlo track structure simulation codes for the walled and the wall-less TEPC counters. The model simulates nonhomogenous tracks in the sensitive volume of the counter and accounts for direct and indirect events. Calculated frequency- and dose-averaged lineal energies 0.3 MeV-1 GeV protons are presented and compared with the experimental data. The calculation of quality factors (QF) were made using individual track histories. Additionally, calculations of absolute frequencies of energy depositions in cylindrical targets, 100 nm height by 100 nm diameter, when randomly positioned and oriented in water irradiated with 1 Gy of protons of energy 0.3-100 MeV, is presented. The distributions show the clustering properties of protons of different energies in a 100 nm by 100 nm cylinder.
地球轨道或深空的太空活动对宇航员和仪器设备风险因素的评估提出了挑战。在太空中，暴露于电离辐射的风险是限制载人太空探索的主要因素之一。因此，在规划太空任务时，根据辐射类型和宇航员所暴露的辐射量来描述辐射环境至关重要。本文报道了对质子和碳离子的热激发极化电流（TEPC）响应的计算。这些计算是使用蒙特卡罗径迹结构模拟代码对有壁和无壁的TEPC计数器进行的。该模型模拟了计数器灵敏体积内的非均匀径迹，并考虑了直接和间接事件。给出了计算得到的0.3 MeV - 1 GeV质子的频率平均和剂量平均线能量，并与实验数据进行了比较。使用单个径迹历史计算了品质因数（QF）。此外，还给出了在1 Gy能量为0.3 - 100 MeV的质子照射水中，当直径100 nm、高100 nm的圆柱形靶随机定位和定向时，能量沉积绝对频率的计算结果。这些分布显示了不同能量质子在100 nm×100 nm圆柱体内的聚集特性。
