Incident angle dependence of secondary electron emission from carbon induced by swift H₂⁺

The incident angle dependence of secondary electron emission induced by a swift H_2^+ ion impinging on carbon is studied using the Monte Carlo method combined with the semiempirical theory. The relationships both between the electron emission yield and the project angle and between the statistics and the projectile angle are investigated. The results show that the backward electron emission yield deviates from the inverse cosine law, due to the effect of the valence electrons of H_2^+. The ratio of the forward electron emission yield to the backward electron emission yield at the inclining incidence is different from that at the normal incidence. The statistical distribution of electron emission is independent of the incident angle. The value of b, the deviation parameter from the Poisson distribution, increases with projectile energy.