A time scale for electrical screening in pulsed gas discharges

Abstract

The Maxwell time is a typical time scale for the screening of an electric field in a medium with a given conductivity. We introduce a generalization of the Maxwell time that is valid for gas discharges: the \emph{ionization screening time}, that takes the growth of the conductivity due to impact ionization into account. We present an analytic estimate for this time scale, assuming a planar geometry, and evaluate its accuracy by comparing with numerical simulations in 1D and 3D. We investigate the minimum plasma density required to prevent the growth of streamers with local field enhancement, and we discuss the effects of photoionization and electron detachment on ionization screening. Our results can help to understand the development of pulsed discharges, for example nanosecond pulsed discharges at atmospheric pressure or halo discharges in the lower ionosphere.

References in corpus (5)

• Review of recent results on streamer discharges and discussion of their relevance for sprites and lightning
• An adaptive grid refinement strategy for the simulation of negative streamers
• Diffusion correction to the avalanche--to--streamer transition
• Controlling the weights of simulation particles: adaptive particle management using k-d trees
• Why isolated streamer discharges hardly exist above the breakdown field in atmospheric air

Cited by in corpus (4)

• The physics of streamer discharge phenomena
• Advanced fluid modelling and PIC/MCC simulations of low-pressure ccrf discharges
• The inception of pulsed discharges in air: simulations in background fields above and below breakdown
• Improvements for drift-diffusion plasma fluid models with explicit time integration