Forward and Backward Secondary Electron Emission from Carbon Foils by O²⁺ Ion

Key words: 
• electron emission /
• electronic energy loss /
• ion beam intensity

Abstract: We have measured the secondary electron emission yields in forward and backward directions from the carbon foils, which are penetrated by O2+ ion of the energy form 1.9 to 11.3 keV/u. In the experiment, the role of electronic energy loss and ion beam intensity in forward and backward electron emission yields have been systematically studied by changing the projectile ion energy and ion beam intensity. The results show that,forward and backward electron emission yields are approximately proportional to the electron energy loss at the exit surfaces and entrance surfaces respectively, and they are independent of the ion beam intensity. Further analyses show that, the kinetic energy threshold for the backward electron emission is about 0.2 keV/u, where the electron emission yield due to the potential energy deposition was roughly 1 e-/ion in the experiment.