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新型X射线探测设备的探索性研究
【作者】 沈扬；
【导师】 Roger Hutton；
【作者基本信息】 复旦大学 ， 原子与分子物理， 2011， 博士
【摘要】 高电荷态离子是宇宙中物质存在的重要形式,光谱学研究手段是对高电荷态离子性质诊断的重要方法。X射线作为电磁波谱中能量覆盖范围很大的一个波段携带了大量信息,对它的观测是研究高电荷态离子内部结构以及它们与其它物质相互作用过程的重要手段。以往由于受到技术的限制,在X射线光谱范围内的能谱观测条件有限。最近几十年,随着半导体技术的发展以及一大批新材料新技术的应用,出现了许多新的探测手段。本论文涉及到电荷耦合器件(CCD)和微卡计这两种探测器,其中CCD探测器因其优异的位置灵敏特性已被广泛应用于光谱分析和成像领域,微卡计则以其高能量分辨率、宽能谱测量范围、高探测效率成为最具潜力的X射线探测设备之一。然而这类探测器涉及真空机械、低温工程、光学、材料、电子线路、控制逻辑、软件等众多学科领域的高尖端技术,目前国内只能通过进口渠道获得CCD探测器,微卡计制造技术更为美国所垄断而难于获得。本课题分为CCD探测器系统研制和微卡计探索性研制两个部分。在第一部分工作中,首先研制并测试了一个可见光线阵CCD系统,为面阵CCD探测器的系统构架、控制信号生成、数据读出和处理等各项功能进行了验证。又在此基础上继续为科研级X射线面阵CCD探测器的研制在真空结构、制冷控制、信号处理等方面进行了一系列预研工作。第二部分是国内首台高能量分辨且高探测效率的微卡计系统的探索性研制工作。完成了整个系统规划设计、真空机械结构设计及一个16通道微卡计输出脉冲信号处理系统设计、组装和相关测试工作。本课题针对高电荷态离子物理研究的需求,希望通过一系列设计和测试工作,为自行研制科研级X射线面阵CCD探测器和微卡计系统进行了一些探索性研究和尝试。
【Abstract】 Most of the matter in our universe exists in plasma form and highly charged ions (HCIs) play an important role in the properties of the hotter objects such as supernovas. X ray spectroscopy is by far the most important technique for investigating the atomic structure and properties of HCIs. In turn, most of the diagnostics of hot astrophysical plasmas is done through X ray spectroscopy of HCIs. HCIs also exist in the central plasma region of Tokamak fusion devises and again X ray spectroscopy is of paramount importance in plasma temperature and density diagnostics.In the past few decades many new techniques for the detection and energy resolution of X rays have been developed. Many of these new techniques have been due to developments of new devices and materials from the semiconductor industry. Two of these developments form the basis of this thesis. One is the de-velopment of charge coupled device, CCD, based detectors, which are widely used in many fields of photon spectroscopy and imaging. The second development is the micro-calorimeter. Micro-calorimeters can measure the energy of an X ray photon with around the same energy resolution as a crystal spectrometer but with much higher efficiency. These devices have been talked about as the most important instrumentation development for astronomy/astrophysics for many years. Devel-opment of both CCD detectors and microcalorimeters involves mastering many techniques and disciplines such as:vacuum engineering, cryogenic engineering, optics, material science, electronic circuit design, logic control, software design and many other disciplines. Currently, China can only obtain CCD detector by importation. Micro-calorimeters are even more difficult to obtain and only a few institutes in USA are capable on offering these.The work in this thesis includes two parts. The first part introduces the design of a linear CCD detector system which validate the system framework, control, signal process and data analysis. Then collect of efforts made in development of an X-ray CCD detector for scientific applications. The second part work is design the first microcalorimeter in China. Include system design, combination and testing of vacuum/mechanical structure and a 16 channel pulse signal digitizer.The primary goal of this thesis is, through a series of advanced technological work, to lay the foundations for developing our own X-ray CCD detectors for scientific applications and also our own microcalorimeter detector.