A new approach for solving the problem of creation of inverse electron distribution function and practical recommendations for experimental searches for such media in glow discharges with hollow and flat cathodes

TL;DR

This paper introduces a new method for creating inverse electron distribution functions in glow discharges, providing criteria, modeling results, and practical guidelines for experimental detection in hollow and flat cathodes.

Contribution

It presents a novel approach for generating inverse electron distribution functions and offers practical recommendations for experimental searches in glow discharges with specific cathode geometries.

Findings

Inverse EDF can be achieved in hollow cathode glow discharges.

Numerical modeling provides criteria for EDF inversion.

Practical guidelines for experimental detection are proposed.

Abstract

This paper proposes a novel approach for creating an inverse electron distribution function (EDF). Based on the obtained criteria for the formation of an inverse EDF in a non-uniform plasma, studies are conducted in low- and medium-pressure glow discharges with flat and hollow cathodes. The results of the numerical modeling and theoretical analysis are used to present reliable criteria and scaling for the evaluation of the possible inversion of the EDF under specific conditions. By solving the nonlocal Boltzmann kinetic equation in energy and coordinate variables, it is shown that the simplest way to implement the inversion of the EDF is in a glow discharge with a hollow cathode. For such discharges, practical recommendations are developed and specific conditions for the experimental detection of an inverse EDF are identified.