Study Of EUV Charge Division Anode Photon Counting Imaging Detector

With the development of the space exploration technology, more and more instruments for detecting weak extreme ultraviolet radiation from different star around earth ultraviolet light are launched into space. Photon counting imaging detector is preferable choice to realize the weak light detection. The research contents and method in the thesis are as follows:1) According to the theory of Micro-Channel Plate(MCP) secondary electron emission, the Comsol software is used to realize the electron multiplication process of the “V” type cascade MCPs. The MCP gain characteristic is research under different voltage. The paper focuses on the derivation of one-dimensional and two-dimensional Vernier anode decoding algorithm. By simulating the imaging of 5×5 pinhole array, the centroid position decoding algorithm can be verified.2) Based on the theory of partition noise,The finite element method of calculating partition noise by Comsol software is proposed. The influences of the partition noise on the centroid position offset of charge cloud are investigated. It is an effective way to reduce the partition noise by increasing the gains of MCP.In addition, the paper discusses the other factors that affect the detector performance, such as the size of electron cloud, the cross-talk between electrodes, electronic noise and the semiconductor thin film.3) Analysis the influence of inter-electrode capacitances on the detector imaging performance. A three-dimensional charge division anode model has been built by ANSYS software and the finite element method has been adopted to calculate the inter-electrode capacitances. The Wedge and Strip(WSZ) anode and the Vernier anode are fabricated with the laser micromachining process. Comparing the simulated capacitances and the measured capacitances, the three-dimensional finite element method is proved to be valid. Furthermore, The finite element method provides a basis for charge division anode structure design.4) The experimental platform is set up to test the main imaging performance of the WSZ anode detector, such as the dark noise, spatial resolution and the different charge readout mode. In addition, the influence of the partition noise and electronic noise on the resolution of the two period Vernier anode detector is evaluated.