On the population density of the argon excited levels in a high power impulse magnetron sputtering dischargeShow others and affiliations
2022 (English)In: Physics of Plasmas, ISSN 1070-664X, E-ISSN 1089-7674, Vol. 29, no 2, p. 023506-, article id 023506Article in journal (Refereed) Published
Abstract [en]
Population densities of excited states of argon atoms in a high power impulse magnetron sputtering (HiPIMS) discharge are examined using a global discharge model and a collisional-radiative model. Here, the ionization region model (IRM) and the Orsay Boltzmann equation for electrons coupled with ionization and excited states kinetics (OBELIX) model are combined to obtain the population densities of the excited levels of the argon atom in a HiPIMS discharge. The IRM is a global plasma chemistry model based on particle and energy conservation of HiPIMS discharges. OBELIX is a collisional-radiative model where the electron energy distribution is calculated self-consistently from an isotropic Boltzmann equation. The collisional model constitutes 65 individual and effective excited levels of the argon atom. We demonstrate that the reduced population density of high-lying excited argon states scales with (p*)(-6), where p * is the effective quantum number, indicating the presence of a multistep ladder-like excitation scheme, also called an excitation saturation. The reason for this is the dominance of electron impact processes in the population and de-population of high-lying argon states in combination with a negligible electron-ion recombination.
Place, publisher, year, edition, pages
AIP Publishing , 2022. Vol. 29, no 2, p. 023506-, article id 023506
National Category
Fusion, Plasma and Space Physics
Identifiers
URN: urn:nbn:se:kth:diva-309275DOI: 10.1063/5.0071887ISI: 000752322700007Scopus ID: 2-s2.0-85124654506OAI: oai:DiVA.org:kth-309275DiVA, id: diva2:1640546
Note
QC 20220224
2022-02-242022-02-242022-06-25Bibliographically approved