Ion velocity distribution functions in argon and helium discharges: detailed comparison of numerical simulation results and experimental data

TL;DR

This study uses Monte Carlo Collisions simulations to accurately model ion velocity distribution functions in argon and helium discharges, validating results with experimental data for drift velocities, diffusion coefficients, and distribution functions.

Contribution

The paper introduces a validated Monte Carlo simulation model that accurately reproduces ion velocity distribution functions in argon and helium discharges, incorporating elastic and charge exchange collisions.

Findings

Simulation results agree well with experimental drift velocities.

The model accurately predicts ion transverse diffusion coefficients.

Validated IVDFs match experimental Legendre polynomial coefficients.

Abstract

Using Monte Carlo Collisions (MCC) method, we have performed simulations of ion velocity distribution functions (IVDF) taking into account both elastic collisions and charge exchange collisions of ions with atoms in uniform electric fields for argon and helium background gases. The simulation results are verified by comparison with the experiment data of the ion drift velocities and the ion transverse diffusion coefficients in argon and helium. The recently published experimental data for the first seven coefficients of the Legendre polynomial expansion of the ion energy and angular distribution functions are used to validate simulation results for IVDF. Good agreements between measured and simulated IVDFs show that the developed simulation model can be used for accurate calculations of IVDFs.