Image Intensifier Device Screen Tester Hot Electron Emission Uniformity

The dissertation is based on a test platform to detect dynamic parameter properties of fluorescent screen of image intensifier.The uniformity of screen illuminating brightness is the base and premise of the whole parameter measurement. After analyzing the illuminating characteristic and testing techniques of screen, the measuring method is established on the basic of analyzing the different assessment criteria of brightness uniformity. As component of lightening the screen, the research of electron gun fitting the testing system is the key technique.On the research work of the relationship of different configurations of hot cathode and its thermal electron emission density, the area source which can emit uniform electrons is designed. Then based on electron optics and using MATLAB program tool, the static electric-field and electron trajectory of the gun in system are realized numerical calculation and simulation. The calculation of electric-field uses finite difference method, the trace using Rongge-Kutta method.Then the configuration of the electron gun is improved to fitting the test system based on analyzing the affection of different field distribution to electron track and the experiment.From statistical-point the affection of electric field distribution to the electron trace is analyzed. Integrating with experiment, the best electric field distribution is found by researching the distribution of points of fall off the screen under different electric field.This work sets the foundation for the illuminating brightness test of screen.