HXMT的空间环境本底计算

Space Environment Background Calculation for HXMT

硬X射线调制望远镜(HXMT)是一颗宽波段X射线(1～250 keV)天文卫星,其核心载荷高能X射线望远镜(HE)工作于硬X射线能区(20～250 keV),致力于实现硬X射线的高灵敏度巡天观测,描绘硬X射线天图,并对特殊天体作高灵敏度定点观测.为了获得高灵敏度,必须有效地抑制本底.本底主要是由轨道环境中的粒子(γ射线、质子、电子、中子)与探测器相互作用产生的.本文结合大量的描述近地空间本底的文献和最新的实测数据,整理出一套自洽的近地空间本底粒子的数据和公式,便于应用.并通过Geant 4软件模拟计算给出了HXMT的本底及本底随时间和轨道的变化.

The Hard X-ray Modulation Telescope （HXMT） is a broad band X-ray （1-250keV） astronomical satellite. Its core payload, High Energy X-ray Telescope （hereafter HE）, operates in the hard X-ray （20-250keV） range. HXMT/HE will perform an all-sky hard X-ray survey and focused observations with the highest sensitivity. To achieve a high sensitivity, it is important to reduce the background that caused by the interactions between the satellite and the space particles. With reference of documents and up-to-date observation data which describe the background of near earth space, a suit of self-consistent data and formulas related to background particle of near earth space are sorted out. The background of HXMT and its variation with time and orbit are also given through simulation calculation with software Geant 4.