Secondary and backscattered electron yields of polymer surface under electron beam irradiation

The radiation behavior of a polymer surface has been investigated employing a scanning electron microscope (SEM). The charging, breakdown or flashover, and electron-blow-off phenomena caused by continuous irradiation have been observed. By positively biasing the polymer surface, the backscattered electrons can be separated from the total electron emission. This method has been applied for the determination of the secondary and backscattered electron yields of polymethylmethacrylate (PMMA), low density polyethylene (LDPE) and polytetrafluoroethylene (PTFE) surfaces. The experimental results reveal that the secondary and backscattered electron yields are dependent on the incident electron beam energy by a power law when the energy is in the range of 5 keV to 35 keV.