Influence of Electron-Electron Collisions on the Formation of Inverse Electron Distribution Function and Absolute Negative Conductivity in Nonlocal Plasma of a DC Glow Discharge

The influence of electron-electron collisions on the formation of inverse electron distribution function (EDF) and absolute negative conductivity (ANC) in nonlocal plasma of a direct current (dc) glow discharge is investigated. The numerical model was created in the COMSOL Multiphysics software environment and includes a kinetic equation for electrons in energy and coordinate variables, drift-diffusion fluid balance equations for heavy particles, and a Poisson equation for finding a self-consistent electric field. It is shown that the Maxwellization of the EDF due to an increase in the role of electron-electron collisions can significantly limit the possibility of the appearance of a reverse EDF and ANC in a nonlocal plasma of rare gases with a Ramsauer minimum of the elastic scattering cross section.