Ion-induced electron and hydrogen ions emission of lead-bismuth silicate glass by ToF

Abstract

A micro-channel Plate (MCP) is a continuous photo-electron multiplier, which has been widely used in the field of particle detectors and low-light night vision imaging devices. The electrons produced by particles collision from the incident end of MCP constitute the useful signal, while the electrons and negative ions produced by collision of ions formed by ionizing gas molecules are considered noise. To reduce the noise from ion collisions, it is important to identify the electron and negative ion emissions caused by collision of unexpected ion. In this paper, the electron and hydrogen ion emissions caused by 1.5MeV Au2+ were analyzed for the cases of acid-etched, alkali-etched, and hydrogen reduced lead-bismuth silicate glass (LBSG). The Time of Flight (ToF) method was used to detect the electron and hydrogen ion emission yields of LBSG. Hydrogen reduction significantly increases the yield of ion-induced electron and negative ions, and the alkali treatment gets the higher yield compared to acid treatment. It is proved that the ToF method is feasible to detect the ion-induced negative particles emission and would be more effectively if the accumulation of positive charges is avoided. The results are valuable not only for noise analysis and manufacturing parameters optimization of low-noise and high-gain MCP, but also as a reference for preparation of new-type micro-channels and investigation on the electron emission properties of glass for space.