Absolute cross sections for He+ impact single ionization of noble gases

He+ impact single ionization cross sections of noble gases have been calculated in the Modified Binary Encounter Approximation. Accurate expression of σ_ΔE (cross section for energy transfer ΔE) and Hartree-Fock velocity distributions for the target electrons have been used throughout the calculations. The present results of single ionization cross sections are in excellent agreement with the experimental observations throughout the energy range. We have also compared our calculated results of H+ impact ionization cross sections of noble gases with experimental measurement of Cavalcanti et al. Our present model is more suitable and gives reliable results. The calculated cross sections differs from the experimental results of H+ impact, this shows that more theoretical calculations is required to understand the dynamics of the system.