We report the first long-term measurements of the radiation quality factor of energetic charged particles on the surface of Mars. The Radiation Assessment Detector (RAD) aboard the Mars Science Laboratory rover, also known as Curiosity, has been operating on Mars since 2012. RAD contains thin silicon detectors that record the ionization energy loss of energetic charged particles. The particles are dominantly galactic cosmic rays (GCRs) and the products of their interactions in the Martian atmosphere, with occasional contributions from solar energetic particles (SEPs). The quality factor on the surface of Mars is influenced by two factors: variations in the shielding provided by the atmosphere, and changes in the spectrum of the incident energetic particle flux due to the 11-year solar cycle. The two cannot be easily disentangled using the data alone, but insights can be gained from calculations and Monte Carlo simulations.

我们报告了火星表面高能带电粒子的辐射质量因子的首次长期测量。自2012年以来，火星科学实验室流动站上的辐射评估探测器（RAD）一直在火星上运行。RAD包含薄硅探测器，用于记录高能带电粒子的电离能损失。这些粒子主要是银河系宇宙射线（GCR）及其在火星大气中相互作用的产物，偶尔还有太阳高能粒子（SEP）的贡献。火星表面的质量因子受两个因素影响：大气层提供的屏蔽的变化以及由于11年的太阳周期而导致的入射高能粒子通量的光谱变化。