Transient behavior of drift and ionization in atmospheric pressure nitrogen discharge

Journal Article · 18 February 2022 · Plasma Sources Science and Technology

DOI: https://doi.org/10.1088/1361-6595/ac43c6 · OSTI ID:1844328

Dhali, S. K.  ^[1]

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1. Old Dominion Univ., Norfolk, VA (United States)

The fluid models are frequently used to describe a non-thermal plasma such as a streamer discharge. The required electron transport data and rate coefficients for the fluid model are parametrized using the local field approximation (LFA) in first order models and the local-mean-energy approximation (LMEA) in second order models. We performed Monte Carlo simulations in Nitrogen gas with step changes in the E/N (reduced electric field) to study the behavior of the transport properties in the transient phase. During the transient phase of the simulation, we extract the instantaneous electron mean energy, which is different from the steady state mean electron energy, and the corresponding transport parameters and rate coefficients. Our results indicate that the mean electron energy is not a suitable parameter for mobility/drift of electrons due to big difference in momentum relaxation and energy relaxation. Furthermore, the high energy threshold rates such as ionization show a strong correlation to mean electron energy. In second order models where the energy-balance equation is solved, we suggest that it would rather be appropriate to use the local electric field to find electron drift velocity in gases such as Nitrogen and the local mean electron energy to determine the ionization and excitation rates.

• Research Organization: Old Dominion Univ., Norfolk, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Fusion Energy Sciences (FES)
• Grant/Contract Number: SC0020183
• OSTI ID: 1844328
• Journal Information: Plasma Sources Science and Technology, Vol. 31, Issue 2; ISSN 0963-0252
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United States
• Language: English