Atomic transport collisions with Lorentzian electron distribution: nonthermal shielding

Abstract

The nonthermal plasma screening effects on the electron-atom transport collision are investigated in partially ionized Lorentzian plasmas. The effective polarization potential and partial-wave theory are applied to obtain the scattering phase shift and transport cross section as functions of the spectral index, collision energy, Debye length and polarizability. The result shows that the nonthermal plasma screening effect suppresses the scattering phase shift as well as the transport cross section in the low-energy domain. It is found that the nonthermal plasma screening effect on the diffusion cross section decreases with an increase of the collision energy. In addition, the nonthermal plasma shielding effects on the excited states are found to be more significant than those on the ground state of the target atom in Lorentzian plasmas. It is also found that the nonthermal screening effect on the 2p state is more significant than that on the 2s state.