基于暗物质粒子探测卫星的亚铁及超铁核素的数据分析与物理研究

There are still many questions that have not been answered clearly although the cosmic ray physics research has been carried out for more than 100 years. The source, acceleration and propagation of the cosmic rays are the three fundamental topics in the modern cosmic ray research. The progress of these three questions is helpful to understand the circumstance of the celestial where cosmic rays were produced and the composition of the interstellar medium where cosmic rays were propagated. The sub-iron elements (Sc,Ti,V,Cr,Mn) are the secondary products of the primary element Iron (Fe), and the abundance ratios between the secondary and the primary are related to the mean free path, one of substantial parameter for the cosmic propagation function. So it’s very meaningful to obtain this parameter from experimental measurement. The ratios of trans-iron element to iron, such as Ga/Fe and Ge/Fe, etc., are useful to understand the material of cosmic ray source and the acceleration mechanism of cosmic rays. It will be provided a determination of the current theoretical model. Beyond searching the dark matter particles, the DArk Matter Particle Explorer (DAMPE) satellite, with the largest energy dynamic range and the best energy resolution in the world, is also a great tool to observe nuclides. The goal of this project based on DAMPE is aimed at the three topics of cosmic ray physic research. It will be accomplished by construction of the charge and energy of the sub-iron and trans-iron elements, and the calculation of the break-up nuclear reaction of target materiat.

宇宙线物理研究已经开展100余年，仍有许多问题没有得到清晰答案。宇宙射线起源、加速和传播是宇宙线物理研究中的三个基本问题，围绕它们的研究有助于理解宇宙线源产生的天体环境及传播过程中的星际介质组成信息。亚铁核素是原初宇宙线Fe的次级产物，通过计算其与母核的丰度比值，可以从实验上得到传播方程中的重要参数平均自由程。超铁核素与Fe的丰度比值研究有助于理解源物质的组分和加速机制，为加速理论模型的可靠与改进提供依据。暗物质粒子探测卫星（DAMPE）是目前世界上拥有最宽观测能段范围和最优能量分辨率等特点的空间探测器，除了用于暗物质粒子探测和寻找外，还是个核素观测望远镜。本项目基于DAMPE，通过进行铁附近元素的电荷及能量重建、靶物质碎裂反应率的计算，得到亚铁和超铁核素的能谱及丰度比值，在此基础上开展宇宙线物理的研究。

宇宙线物理研究已经开展100余年，仍有许多问题没有得到清晰答案。宇宙射线起源、加速和传播是宇宙线物理研究中的三个基本问题，围绕它们的研究有助于理解宇宙线源产生的天体环境及传播过程中的星际介质组成信息，如亚铁元素的丰度研究有助于揭示宇宙线的传播机制，超铁元素中的丰度研究有助于理解源物质的组分和加速机制。暗物质粒子探测卫星（DAMPE）是目前世界上拥有最宽观测能段范围和最优能量分辨率等特点的空间探测器，除了用于暗物质粒子探测和寻找外，还是个核素观测望远镜。DAMP主要由塑闪阵列探测器（PSD）、BGO量能器、硅径迹探测器和中子探测器等四个不同的探测器组成。其中，PSD主要承担了DAMPE中的核素鉴别功能。本项目的研究工作主要依托于DAMPE开展。在项目执行过程中，本项目进行了包括PSD在轨基础标定、好事例预选、对齐修正和淬灭效应修正等细致在轨电荷重建工作，得到了PSD对Z=1~40等不同核素的鉴别能力，其电荷分辨能力为0.059@Z=1和0.3@Z=26。最终，对核素能量阈值构建方法和核素的丰度进行了分析。因此，本项目基本完成了预期目标。