XPS Analysis of Inner Coating in Channel Electron Multiplier

The elemental composition and the valence states of atoms in the secondary electron emission (SEE) layer of channel electron multiplier (CEM) were analysed using XPS depth profiling combined with argon ion sputtering. The results show that the surface of SEE layer is mainly composed of Pb, Bi, Ba, Si and O, in which the valence states of Pb are 0 and +2 while those of Bi are 0 and +3.