| Space Plasma Detection has been the center of attention for space scientists since the end of20th century. The research on space plasma is significant for the aerospace industry, radio communication, solar wind early warning, the research on planetary atmosphere, etc. In the recent years, techniques on measuring the charge, the mass, and the energy information of the space plasmas have being developed rapidly. Till now, the European countries and America have launched many satellites for plasma detection around near-earth orbits, such as:Cluster, FAST, WIND, GIOTTO, AMPTE, etc. There are different sorts of plasma detectors in these satellites, however, the detectors can achieve the same purpose finally. On the other hand, similar instruments have been loaded on planet detectors such as Mars Express and Venus Express, and comet detectors such as ROSETTA.The "Top-hat" electrostatic analyzer (ESA) is widely used in space plasma detection, the analyzer can select the incoming ions according to their energy charge ratio by supplying various reference voltage to its inner and outer semispheres. In addition, time-of-flight (TOF) systems are frequently used for measuring the flight speed of the selected ions. The techniques on space plasma detections have been developed much earlier in the foreign countries than in China. We conducted an investigation into space plasma detector independently using the foreign ones as a reference, and this paper is on the development of principle prototype of the "Top-hat" ESA based ion detector and its read-out electronics, as well as the resercch on the key technology for TOF system:Chapter1introduces the background study of space plasmas, and shows the different sorts of instruments that can be applied in space plasma detection. Finally, some space detectors including the introduced detectors are presented.In chapter2, the work on the development of principle prototype of the "Top-hat" ESA based ion detector and its read-out electronics is presented. The detector and the read-out electronics structures, the performance as well as the parameters are describled in detail, and the overall calibrating plan is also presented.Chapter3introduces different kinds of time-of-flight measurement systems in space plasma detection, and explans their operation principle. The needed fuctions of time-of-flight electronics are decribled, and the key techniques as well as difficulties are also mentioned. In chapter4, the research on the key technique of read-out electronics in space plasma detectors is discussed. High resolution time-to-digital convenors (TDC) are implemented repectively in Actel Flash-based and Anti-fuse based FPGAs. The TDC is based on time interpolating method employing time delay chains, and the architecture and test results are describled in detail, In Flash-based FPGAs, the delay element for the delay chain is CMOS Buffer, and in Anti-fuse FPGA, the delay element is the dedicated carry chain. Finally, the radiation-torlerant performance of Actel radiation strengthening FPGAs is illustrated.Chapter5discusses the temperature drift of FPGA-based TDC bin size according to the thermal tests. The TDC bin size changes linearly with temperature, thus the linear function algotithm is employed for correction. The correcting precision of the linear function algotithm is proved by comparing with the code-density method.Chapter6presents some methods on improving the TDC timing performance: multi-time averaging method and vernier delay chains method, In the discussion of multi-time averaging method, wave-union and parallel delay chains methods are included. At last, the consumed resources for these methods are showed for comparision.Chapter7introduces the schematic design of the readout electronics prototype for the TOF system in the space plasma detector, and preliminary test results are presented. Meanwhile, the future work for the TOF system is illustrated.Chapter8summarizes our work on the research of space plasma detection, and prospects the future work. |
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