Electron emission induced by keV protons from tungsten surface at different temperatures

The electron emission yield is measured from the tungsten surface bombarded by the protons in an energy range of 50 keV-250 keV at different temperatures. In our experimental results, the total electron emission yield, which contains mainly the kinetic electron emission yield, has a very similar change trend to the electronic stopping power. At the same time, it is found that the ratio of total electron emission yield to electronic stopping power becomes smaller as the incident ion energy increases. The experimental result is explained by the ionization competition mechanism between electrons in different shells of the target atom. The explanation is verified by the opposite trends to the incident energy between the ionization cross section of M and outer shells.