基于MAPS的星载硅径迹探测器及读出电子学原理研究

Silicon tracker detector has already become a fundamental part of the payload for space-borne cosmic ray experiments. However, almost all of the silicon trackers currently in space are made of silicon strip detectors, in which only one-dimension position information can be obtained from each strip plane. Therefore the image blurring effect can be introduced when one single strip are "fired" by multiple particles coincidently, which brings great difficulty to offline tacking-reconstruction.. Even though being a new technology which has become mature enough just in several years, the Monolithic Active Pixel Sensor (MAPS) has shown significant advantages in vertex detectors for ground-based particle physics experiments. Based on standard CMOS technologies, a sensor and its front-end circuits are implemented in each pixel and two-dimension hit information can be directly and rapidly obtained. This not only simplifies the algorithm of position reconstruction and eliminates the blurring effect, but also greatly improves the time resolution. Together with other features such as higher integrity and better radiation tolerance compared to traditional silicon strips, MAPS also seems to open new perspectives for charged particle tracking in space-borne experiments.. In this project, the study on the principal and feasibility of MAPS-based silicon tracker for space application is proposed. Based on existed MAPS chips which have been successfully employed on ground, a prototype MAPS detector with one or two small ladders will be developed, as well as the corresponding readout electronics. Other techniques which are supposed to be critical for future usage of MAPS in space, such as the high speed data transmission protocol, the radiation performance and possible hardness method, will be studied or evaluated as well.

硅径迹探测器在空间宇宙线探测实验中发挥着重要的作用。现有的星载硅径迹探测器多采用硅微条实现，由于每个读出面只能获得一维位置信息，当发生多重击中时会导致位置模糊，从而影响径迹重建效果。单片有源像素传感器（MAPS）是近几年发展成熟并已在地面实验得到应用的一种新型硅像素探测器，其每个像素内部集成了探测灵敏区和读出电路，可高计数率地直接获得高分辨的二维位置信息，且有效地消除了多重击中问题。其集成度高，抗辐射能力强，在空间粒子探测领域具有很大的应用潜力。. 本课题拟选用国内外成熟的MAPS芯片，探索新型星载硅径迹探测器的技术方案，设计一至二层小面积的MAPS探测器组件及相应的读出电子学原型电路，并开展抗辐射性能评估及加固措施研究。针对MAPS像素通道数庞大的特点，还将开展高速数据传输研究，希望为将来的星载应用做好技术储备。

硅径迹探测器在空间宇宙线探测实验中发挥着重要的作用。现有的星载硅径迹探测器多采用硅微条实现，由于每个读出面只能获得一维位置信息，当发生多重击中时会导致位置模糊，从而影响径迹重建效果。单片有源像素传感器（MAPS）是近些年来发展成熟并已在地面实验得到应用的一种新型硅像素探测器，其每个像素内部集成了探测灵敏区和读出电路，因为采用像素读出而能够避免多重击中的问题，且具有高位置分辨、高集成度、抗辐射能力强等诸多优点，在空间粒子探测领域具有很大的应用潜力。. 本项目开展了面向星载应用的硅径迹探测器技术方案的原理探索。选用了一款在地面大科学实验中得到应用的MAPS芯片，设计了原型电路，并研究了该MAPS芯片的数据接口和参数配置方案，最终研制完成了一套原型读出电子学系统，包括读出电路模块、FPGA逻辑、以及上位机（PC）数据采集软件等。基于该系统，完成了Fe-55放射源测试、X光机测试、红外激光测试等。在此基础上，通过与德国DESY（电子同步加速器实验室）开展合作，研制了一套6层的硅像素望远镜（径迹探测器）系统，并利用DESY T22的0.5-6 GeV 高能电子束流成功开展了多次实验，对该系统的功能和性能指标进行了全面验证。