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On the mechanism of branching in negative ionization fronts

M. Arrayas·M. A. Fontelos·J. L. Trueba
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Abstract

We explain a mechanism for branching of a planar negative front. Branching occurs as the result of a balance between the destabilizing effect of impact ionization and the stabilizing effect of electron diffusion on ionization fronts. The dispersion relation for transversal perturbation is obtained analytically and reads: $s = |k|/[2 (1 + |k|)] - D |k|^2$, where $D$, which is assumed to be small, is the ratio between the electron diffusion coefficient and the intensity of the externally imposed electric field. We estimate the spacing $λ$ between streamers in a planar discharge and deduce a scaling law $λ\sim D^{1/3}$.

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M. Arrayas, M. A. Fontelos, J. L. Trueba. 2005-05-18. On the mechanism of branching in negative ionization fronts. https://doi.org/10.1103/physrevlett.95.165001

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