Secondary electron emission from carbon foils under O²⁺ ion impact

Secondary electron emission yields in forward and backward direction from carbon foils (thickness of 74 nm) induced by O²⁺ ions of energies form 1.9 keV/u to 11.3 keV/u have been measured. We find that the forward and the backward electron emission yields increase with the projectile kinetic energy. Further studies showed that the forward and the backward electron emission yields are approximately proportional to the electronic stopping power at the exit and entrance surfaces, respectively.