Benchmarked and upgraded particle-in-cell simulations of a capacitive argon discharge at intermediate pressure: the role of metastable atoms
Year: 2021
Type: article
Abstract: The capacitive argon discharge operated in the intermediate pressure regime is studied by performing one-dimensional particle-in-cell Monte Carlo collision simulations. First, the basic object-oriented plasma device code ( oopd1-v1 ) is strictly benchmarked against the well-established xpdp1 code over a wide range of pressure (0.05–15 Torr) and varying blocking capacitor of the external circuit (5–10 5 nF), and excellent agreement is obtained. The oopd1-v1 is upgraded to oopd1-v2 and oopd1-v3 , by adding excited atoms modeled as time- and space-evolving fluid species. The metastable Ar m , the radiative Ar r , and the Ar(4p) manifold, and their roles in discharge equilibrium are explored. It is found that the presence of the metastable Ar m enhances the plasma density by a factor of 3 at 1.6 Torr and even higher at pressures up to 5 Torr. At low pressure (0.05 Torr), electron impact ionization from the ground state atom dominates the ionization over the whole discharge region, while metastable pooling and step-wise ionization has small contribution. The proportion of metastable pooling ionization and step-wise ionization increases with increasing pressure and becomes the dominant ionization source at 5–15 Torr.
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W3187757891