The enhanced X-ray Timing and Polarimetry mission—eXTP

In this paper we present the enhanced X-ray Timing and Polarimetry mission—eXTP. eXTP is a space science mission designed to study fundamental physics under extreme conditions of density, gravity and magnetism. The mission aims at determining the equation of state of matter at supra-nuclear density, measuring effects of QED, and understanding the dynamics of matter in strong-field gravity. In addition to investigating fundamental physics, eXTP will be a very powerful observatory for astrophysics that will provide observations of unprecedented quality on a variety of galactic and extragalactic objects. In particular, its wide field monitoring capabilities will be highly instrumental to detect the electro-magnetic counterparts of gravitational wave sources.The paper provides a detailed description of:(1) the technological and technical aspects, and the expected performance of the instruments of the scientific payload;(2) the elements and functions of the mission, from the spacecraft to the ground segment.

用于软X射线探测器标定的X射线二次多靶源

爱因斯坦探针(Einstein Probe,EP)和增强型X射线时变与偏振探测天文台(enhanced X-ray Timing and Polarimetry,eXTP)是近期提出的两种聚焦型X射线天文望远镜。EP卫星搭载的深度后随X射线望远镜(Follow-up X-ray Telescope,FXT)和eXTP卫星搭载的能谱测量X射线聚焦望远镜阵列(Spectroscopy Focusing Array,SFA)分别使用了pnCCD和SDD探测器。pnCCD和SDD前期电子学联调和标定在中国科学院高能物理研究所标定大厅进行,所用的X射线靶源是标定装置的重要部件。本文介绍了一种X射线二次多靶源装置的设计,该装置可以为联调和标定工作提供软X射线光源。装置利用X光机电子打靶所产生的韧致辐射光子二次打靶放出二次靶材的荧光线,生成能谱成分简单、信噪比高的X射线光源。通过Geant4模拟对该装置的准直管口径、X光机管高压和装置内壁材料等参数进行了分析,然后对SDD和pnCCD进行了能谱测量,同时利用pnCCD的成像功能对光源的光斑大小进行了测试。结果显示:该装置可以满足联调需求,能够广泛应用于软X射线探测器的前期电子学联调和测试。