Medical Physics Laboratory, Department of Medicine, University of Ioannina, 45110, Ioannina, Greece.
University of Bordeaux, CNRS, LP2I, UMR 5797, F-33170, Gradignan, France.
Radiat Environ Biophys. 2023 May;62(2):221-234. doi: 10.1007/s00411-023-01023-6. Epub 2023 Apr 16.
Space radiation exposure from omnipresent Galactic Cosmic Rays (GCRs) in interplanetary space poses a serious carcinogenic risk to astronauts due to the-limited or absent-protective effect of the Earth's magnetosphere and, in particular, the terrestrial atmosphere. The radiation risk is directly influenced by the quality of the radiation, i.e., its pattern of energy deposition at the micron/DNA scale. For stochastic biological effects, radiation quality is described by the quality factor, [Formula: see text], which can be defined as a function of Linear Energy Transfer (LET) or the microdosimetric lineal energy ([Formula: see text]). In the present work, the average [Formula: see text] of GCR for different mission scenarios was calculated using a modified version of the microdosimetric Theory of Dual Radiation Action (TDRA). NASA's OLTARIS platform was utilized to generate the radiation environment behind different aluminum shielding (0-30 g/cm) for a typical mission scenario in low-earth orbit (LEO) and in deep space. The microdosimetric lineal energy spectra of ions ([Formula: see text]) in 1 μm liquid water spheres were calculated by a generalized analytical model which considers energy-loss fluctuations and δ-ray transport inside the irradiated medium. The present TDRA-based [Formula: see text]-values for the LEO and deep space missions were found to differ by up to 10% and 14% from the corresponding ICRP-based [Formula: see text]-values and up to 3% and 6% from NASA's [Formula: see text]-model. In addition, they were found to be in good agreement with the [Formula: see text]-values measured in the International Space Station (ISS) and by the Mars Science Laboratory (MSL) Radiation Assessment Detector (RAD) which represent, respectively, a LEO and deep space orbit.
太空中无处不在的银河宇宙射线（GCR）会对宇航员造成严重的致癌风险，因为地球磁场，特别是地球大气层的保护作用有限或不存在。辐射风险直接受到辐射质量的影响，即其在微米/DNA 尺度上的能量沉积模式。对于随机生物效应，辐射质量由品质因数[Formula: see text]来描述，它可以定义为线性能量传递（LET）或微剂量线性能量[Formula: see text]的函数。在本工作中，使用改良的双辐射作用微剂量理论（TDRA），计算了不同任务场景下 GCR 的平均[Formula: see text]。利用 NASA 的 OLTARIS 平台，为低地球轨道（LEO）和深空的典型任务场景，生成了不同铝屏蔽（0-30g/cm）背后的辐射环境。通过考虑辐照介质内能量损失波动和δ射线输运的广义解析模型，计算了 1μm 液水滴中离子的微剂量线性能量谱[Formula: see text]。本工作基于 TDRA 的 LEO 和深空任务的[Formula: see text]值，与相应的 ICRP 基于[Formula: see text]值的差异高达 10%和 14%，与 NASA 的[Formula: see text]模型的差异高达 3%和 6%。此外，它们与国际空间站（ISS）和火星科学实验室（MSL）辐射评估探测器（RAD）测量的[Formula: see text]值吻合较好，分别代表 LEO 和深空轨道。
