Mechanistic study on the micro-optical morphology and electrical properties of microchannel plates by acid-base alternating corrosion processes

Abstract

Abstract As a two-dimensional vacuum electron multiplier device, the microchannel plate is made by solid method with lead silicate glass as the base material, and acid-base etching to remove the core material is a key step in the formation of the microchannel plate, which mainly affects the microstructure, morphology and composition of the inner wall surface, and then affects the electrical properties of the microchannel plate. The microscopic morphology of silicate glass under different etching processes was studied by scanning electron microscopy, and it was found that with the increase of acid-base alternation during the etching process, the particle density of the inner wall of the channel gradually decreased, and the energy spectrum analysis of the particles revealed that the main contents were Pb and Bi; further by AFM analysis, the particle peak height was reduced from 31.1 nm to 1.9 nm with roughness. The results of the electrical and noise properties of the microchannel plates show that an appropriate increase in acid-base alternation can effectively reduce the bulk resistance and dark current without reducing the gain of the microchannel plates. This shows that increasing the "erosion intensity" of the acid-base alternation multiple times during corrosion can effectively improve the core-skin diffusion layer, further affecting the physical and chemical transformation of the nanoscale morphology, pointing to a new direction for improving the electrical properties of microchannel plates made of silicate glass.