Heavy Particle Impact-Ionization of Atoms in Classical Theory

Abstract
Heavy charged particle (proton, deuteron and He + ion) impact ionization cross-sections of the noble gas atoms have been calculated using Gryzinski's formula with exponential velocity distribution function. Low energy behavior of the cross-section formula is investigated and the threshold expression given by Gryzinski is found to be incorrect. Dependence of the cross-section on the mass of the system is also discussed.