Space radiation is one of the main concerns in planning long-term human space missions. There are two main types of hazardous radiation: solar energetic particles (SEP) and galactic cosmic rays (GCR). The intensity and evolution of both depends on solar activity. GCR activity is most enhanced during solar minimum and lowest during solar maximum. The reduction of GCRs is alagging behind solar activity only by 6–12 month. SEP probability and intensity are maximized during solar maximum and are minimized during solar minimum. In this study, we combine models of the particle environment arising due to SEP and GCR with Monte Carlo simulations of radiation propagation inside a spacecraft and phantom. We include 28 fully ionized GCR elements from hydrogen to nickel and consider protons and nine ion species to model the SEP irradiation. Our calculations demonstrate that the optimal time for a flight to Mars would be launching the mission at solar maximum, and that the flight duration should not exceed approximately 4 years.

中文翻译：

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击败 1 Sievert：执行火星任务的宇航员的最佳辐射屏蔽

空间辐射是规划长期载人航天任务的主要问题之一。有两种主要类型的有害辐射：太阳高能粒子 (SEP) 和银河宇宙射线 (GCR)。两者的强度和演化取决于太阳活动。GCR 活动在太阳活动极小期期间增强最大，而在太阳活动极期活动期间最低。GCR 的减少仅比太阳活动滞后 6-12 个月。SEP 概率和强度在太阳活动极大期时最大化，在太阳活动极小期时最小化。在这项研究中，我们将 SEP 和 GCR 引起的粒子环境模型与航天器和体模内辐射传播的蒙特卡罗模拟相结合。我们包括从氢到镍的 28 种完全电离的 GCR 元素，并考虑使用质子和 9 种离子来模拟 SEP 辐射。