Southwest Research Institute, Space Science and Engineering Division, 1050 Walnut Street, Suite 300, Boulder, CO 80302, USA.
Leidos, Innovations Corporation, Houston, TX, USA.
Life Sci Space Res (Amst). 2017 Aug;14:3-11. doi: 10.1016/j.lssr.2017.07.004. Epub 2017 Jul 8.
The Radiation Assessment Detector (RAD) on board the Mars Science Laboratory (MSL) Curiosity rover has been measuring the radiation environment in Gale crater on Mars since August, 2012. These first in-situ measurements provide an important data set for assessing the radiation-associated health risks for future manned missions to Mars. Mainly, the radiation field on the Martian surface stems from Galactic Cosmic Rays (GCRs) and secondary particles created by the GCRs' interactions with the Martian atmosphere and soil. RAD is capable of measuring differential particle fluxes for lower-energy ions and isotopes of hydrogen and helium (up to hundreds of MeV/nuc). Additionally, RAD also measures integral particle fluxes for higher energies of these ions. Besides providing insight on the current Martian radiation environment, these fluxes also present an essential input for particle transport codes that are used to model the radiation to be encountered during future manned missions to Mars. Comparing simulation results with actual ground-truth measurements helps to validate these transport codes and identify potential areas of improvements in the underlying physics of these codes. At the First Mars Radiation Modeling Workshop (June 2016 in Boulder, CO), different groups of modelers were asked to calculate the Martian surface radiation environment for the time of November 15, 2015 to January 15, 2016. These model results can then be compared with in-situ measurements of MSL/RAD conducted during the same time frame. In this publication, we focus on presenting the charged particle fluxes measured by RAD between November 15, 2015 and January 15, 2016, providing the necessary data set for the comparison to model outputs from the modeling workshop. We also compare the fluxes to initial GCR intensities, as well as to RAD measurements from an earlier time period (August 2012 to January 2013). Furthermore, we describe how changes and updates in RAD on board processing and the on ground analysis tools effect and improve the flux calculations. An in-depth comparison of modeling results from the workshop and RAD fluxes of this publication is presented elsewhere in this issue (Matthiä et al., 2017).
火星科学实验室（MSL）好奇号漫游车上的辐射评估探测器（RAD）自 2012 年 8 月以来一直在测量盖尔陨石坑内的辐射环境。这些首次现场测量为评估未来载人火星任务与辐射相关的健康风险提供了重要数据。主要的，火星表面的辐射场源于银河宇宙射线（GCRs）和 GCRs 与火星大气和土壤相互作用产生的次级粒子。RAD 能够测量低能氢离子和氦同位素的微分粒子通量（高达数百 MeV/nuc）。此外，RAD 还能测量这些离子更高能量的积分粒子通量。除了提供当前火星辐射环境的深入了解，这些通量也为粒子输运模型提供了必要的输入，这些模型用于模拟未来载人火星任务中遇到的辐射。将模拟结果与实际地面测量结果进行比较，有助于验证这些输运模型，并确定这些模型中潜在的物理改进领域。在第一届火星辐射建模研讨会上（2016 年 6 月在科罗拉多州博尔德举行），要求不同的建模小组计算 2015 年 11 月 15 日至 2016 年 1 月 15 日期间的火星表面辐射环境。然后，可以将这些模型结果与同一时期 MSL/RAD 的现场测量结果进行比较。在本出版物中，我们重点介绍了 2015 年 11 月 15 日至 2016 年 1 月 15 日期间由 RAD 测量的带电粒子通量，为与建模研讨会的模型输出进行比较提供了必要的数据集。我们还将通量与初始 GCR 强度以及 RAD 更早时期（2012 年 8 月至 2013 年 1 月）的测量结果进行了比较。此外，我们描述了 RAD 船上处理和地面分析工具的变化和更新如何影响和改进通量计算。本出版物中的 RAD 通量与研讨会建模结果的深入比较在本期其他地方进行了介绍（Matthiä 等人，2017）。
