火星表面辐射环境分析

火星表面没有全球性磁场保护，存在较强的辐射环境。文章基于Mars-GRAM模型和MCD模型的火星大气数据、“海盗号”（Viking Lander 1/2）及“探路者号”（Pathfinder）等测量得到的火星土壤数据、银河宇宙射线环境（CREME 96模型）以及太阳宇宙射线环境（1989年10月太阳事件），采用基于GEANT4的粒子输运方法，分析得到了火星表面辐射环境；并与“好奇号”火星车辐射评价探测器（Radiation Assessment Detector，RAD）实测值进行了比较。结果显示：次级伽马光子和中子通量分析值与实测值偏差不超过50%，辐射剂量分析值与实测值偏差不超过5%。火星表面辐射环境可用于分析航天员在不同位置处遭遇的人体剂量，作为载人火星任务着陆点数据参考。

Analysis of radiation environment on Mars surface

The lack of the global magnetic field around the Mars results in a relatively severe radiation environment on the Mars’ surface. In this paper, the radiation environment on the Mars’ surface is analyzed through the particle transport method using GEANT4, based on the Mars’ atmosphere data obtained from the Mars-GRAM model and the MCD model, with the soil data obtained by the Viking Lander 1/2 and Mars Pathfinder, and the GCRs (CREME 96 model) and SCRs environment(Solar Event of October 1989). The analysis results are compared with the measurement data from the Radiation Assessment Detector (RAD) onboard the rover Curiosity. The relative deviation between the analysis results and the measurement data is less than 50% for the secondary gamma ray and the neutron flux, and is less than 5% for the total radiation dose. The human dose received by the astronaut at different positions of Mars’ surface can be derived from the Mars’ surface radiation environment, to serve as a reference for selecting the appropriate landing region for the manned Mars exploration mission.