Interface Diffusion Between Clad And Core Glass Of Microchannel Plate And Simulation Of Electron Multiplication Theory

Microchannel plates(MCP)has high gain,low noise,high resolution,wide dynamic and other excellent characteristics,which is widely used in many fields including weak photoelectric signal imaging,spacious single photon detection,high energy particle detection,and nuclear diagnosis.The gain as the basic performance of the microchannel plate determines practical application of MCP.The microstructure and composition of the inner surface of the microporous directly affect the secondary electron yield,and further determines the gain of the microchannel plate.The interface state of the core-clad glass under the pressed disc method with different conditions,and the diffusion properties of the interface of the microchannel core-clad glass under various hot processing conditions were studied.The relationship between the interface state of micro porous inner wall and the gain theoretical model was constructed,and the simulation and optimization of the gain theoretical model was realized.Firstly,the diffusion distance of element ions between the interface of core-clad glass during the preparation process of microchannel plate for the mono-fiber,multi-fiber drawing and blank hot-pressing was studied.The interface diffusion of the microchannel plate glass was simulated by the pressed disc method,and the interface diffusion samples under different temperature and pressure were obtained.The change of diffusion degree and the influence on the microstructure of the interface were analyzed.The results show that the diffusion capacity of different ions in the glass interface of the microchannel plate is different,and is influenced by the temperature and pressure,and increases with the increase of temperature and pressure.The diffusion capacity of the interface is affected by temperature and pressure,and increases with the increase of temperature and pressure.The roughness of the inner surface of the micropore increases with the increase of interfacial diffusion,and the island structure appears on the surface of the glass after etching.The island particles are formed at the interface when the fibers are drawn,indicating the mutual reaction and diffusion on the core glass interface.Secondly,the influence of the temperature of the mono-fiber and multi-fiber drawing and the blank hot pressing on the element diffusion behavior between the interface of the core-clad glass during the preparation of the MCP were analyzed.The microchannel blank was treated by acid etching,reduction and coating process,and the electronic gain was measured.The results show different production process parameters have obvious influence on the diffusion tendency of the core-clad glass interface,and then influence the gain size.The influence of temperature change of the mono-fiber and multi-fiber drawing,and the blank hot pressing on electron gain is obviously different.Finally,based on the MCP gain theoretical model,the influence of the ratio of channel length to diameter,the working voltage of MCP and the angle of incident angle on the electronic gain and the transit time were simulated.The advantages and disadvantages of each theoretical model were analyzed.Based on the research results of interface diffusion,the correction model of "energy proportional hypothesis" is optimized.Using the Monte Carlo mathematical random method and the Furman second electron emission probability model to simulate the process of electronic transmission,collision and multiplication of the MCP,the simulation results coincide with the experimental gain results.At the same time,according to the gain at different drawing temperatures,the parameters related to the surface condition in the theoretical model are calculated,and the related parameters in the modified theoretical model are optimized.