Effect of a weak ion collisionality on the dynamics of kinetic electrostatic shocks
Artikel i vetenskaplig tidskrift, 2019

In strictly collisionless electrostatic shocks, the ion distribution function can develop discontinuities along phase-space separatrices, due to partial reflection of the ion population. In this paper, we depart from the strictly collisionless regime and present a semi-analytical model for weakly collisional kinetic shocks. The model is used to study the effect of small but finite collisionalities on electrostatic shocks, and they are found to smooth out these discontinuities into growing boundary layers. More importantly, ions diffuse into and accumulate in the previously empty regions of phase space, and, by upsetting the charge balance, lead to growing downstream oscillations of the electrostatic potential. We find that the collisional age of the shock is the more relevant measure of the collisional effects than the collisionality, where the former can become significant during the lifetime of the shock, even for weak collisionalities.

plasma waves

plasma nonlinear phenomena

Författare

Andréas Sundström

Chalmers, Fysik, Subatomär fysik och plasmafysik

James Juno

University of Maryland

Jason M. TenBarge

Princeton University

Princeton Plasma Physics Laboratory

Istvan Pusztai

Chalmers, Fysik, Subatomär fysik och plasmafysik

Journal of Plasma Physics

0022-3778 (ISSN) 1469-7807 (eISSN)

Vol. 85 1 905850108

Plasmabaserade kompakta jonkällor

Knut och Alice Wallenbergs Stiftelse, 2014-07-01 -- 2019-06-30.

Skena och skina

Europeiska kommissionen (Horisont 2020), 2015-10-01 -- 2020-09-30.

Fundament

Grundläggande vetenskaper

Ämneskategorier

Annan fysik

Fusion, plasma och rymdfysik

DOI

10.1017/S0022377819000023

Mer information

Senast uppdaterat

2019-12-18