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Transition from Townsend to glow discharge: subcritical, mixed or supercritical

Danijela D. Sijacic·Ute Ebert
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Abstract

The full parameter space of the transition from Townsend to glow discharge is investigated numerically in one space dimension in the classical model: with electrons and positive ions drifting in the local electric field, impact ionization by electrons ($α$ process), secondary electron emission from the cathode ($γ$ process) and space charge effects. We also perform a systematic analytical small current expansion about the Townsend limit up to third order in the total current that fits our numerical data very well. Depending on $γ$ and system size pd, the transition from Townsend to glow discharge can show the textbook subcritical behavior, but for smaller values of pd, we also find supercritical or some intermediate ``mixed'' behavior. The analysis in particular lays the basis for understanding the complex spatio-temporal patterns in planar barrier discharge systems.

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Danijela D. Sijacic, Ute Ebert. 2003-01-15. Transition from Townsend to glow discharge: subcritical, mixed or supercritical. https://doi.org/10.1103/physreve.66.066410

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