Simulations of Ion Velocity Distribution Functions Taking into Account   Both Elastic and Charge Exchange Collisions
  Based on accurate representation of the He+-He angular differential scattering cross sections consisting of both elastic and charge exchange collisions, we performed detailed numerical simulations of the ion velocity distribution functions (IVDF) by Monte Carlo collision method (MCC). The results of simulations are validated by comparison with the experimental data of the ion mobility and the transverse diffusion. The IVDF simulation study shows that due to significant effect of scattering in elastic collisions IVDF cannot be separated into product of two independent IVDFs in the transverse and parallel to the electric field directions. 
Huihui Wang, Vladimir S. Sukhomlinov, Igor D. Kaganovich, Alexander S.   Mustafaev
physics.plasm-ph