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Title: Particle-in-cell simulation study of a lower-hybrid shock

Abstract

The expansion of a magnetized high-pressure plasma into a low-pressure ambient medium is examined with particle-in-cell simulations. The magnetic field points perpendicular to the plasma's expansion direction and binary collisions between particles are absent. The expanding plasma steepens into a quasi-electrostatic shock that is sustained by the lower-hybrid (LH) wave. The ambipolar electric field points in the expansion direction and it induces together with the background magnetic field a fast E cross B drift of electrons. The drifting electrons modify the background magnetic field, resulting in its pile-up by the LH shock. The magnetic pressure gradient force accelerates the ambient ions ahead of the LH shock, reducing the relative velocity between the ambient plasma and the LH shock to about the phase speed of the shocked LH wave, transforming the LH shock into a nonlinear LH wave. The oscillations of the electrostatic potential have a larger amplitude and wavelength in the magnetized plasma than in an unmagnetized one with otherwise identical conditions. The energy loss to the drifting electrons leads to a noticeable slowdown of the LH shock compared to that in an unmagnetized plasma.

Authors:
;  [1]; ; ;  [2]
  1. Department of Science and Technology, Linköping University, SE-60174 Norrköping (Sweden)
  2. School of Mathematics and Physics, Queen's University, Belfast BT7 1NN (United Kingdom)
Publication Date:
OSTI Identifier:
22598973
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 23; Journal Issue: 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AMPLITUDES; COLLISIONS; COMPARATIVE EVALUATIONS; ELECTRIC FIELDS; ELECTRON DRIFT; ELECTRONS; ENERGY LOSSES; IONS; LOWER HYBRID CURRENT DRIVE; LOWER HYBRID HEATING; MAGNETIC FIELDS; NONLINEAR PROBLEMS; OSCILLATIONS; PARTICLES; PLASMA PRESSURE; POTENTIALS; PRESSURE GRADIENTS; SIMULATION; VELOCITY; WAVELENGTHS

Citation Formats

Dieckmann, M. E., Ynnerman, A., Sarri, G., Doria, D., and Borghesi, M.. Particle-in-cell simulation study of a lower-hybrid shock. United States: N. p., 2016. Web. doi:10.1063/1.4953568.
Dieckmann, M. E., Ynnerman, A., Sarri, G., Doria, D., & Borghesi, M.. Particle-in-cell simulation study of a lower-hybrid shock. United States. doi:10.1063/1.4953568.
Dieckmann, M. E., Ynnerman, A., Sarri, G., Doria, D., and Borghesi, M.. 2016. "Particle-in-cell simulation study of a lower-hybrid shock". United States. doi:10.1063/1.4953568.
@article{osti_22598973,
title = {Particle-in-cell simulation study of a lower-hybrid shock},
author = {Dieckmann, M. E. and Ynnerman, A. and Sarri, G. and Doria, D. and Borghesi, M.},
abstractNote = {The expansion of a magnetized high-pressure plasma into a low-pressure ambient medium is examined with particle-in-cell simulations. The magnetic field points perpendicular to the plasma's expansion direction and binary collisions between particles are absent. The expanding plasma steepens into a quasi-electrostatic shock that is sustained by the lower-hybrid (LH) wave. The ambipolar electric field points in the expansion direction and it induces together with the background magnetic field a fast E cross B drift of electrons. The drifting electrons modify the background magnetic field, resulting in its pile-up by the LH shock. The magnetic pressure gradient force accelerates the ambient ions ahead of the LH shock, reducing the relative velocity between the ambient plasma and the LH shock to about the phase speed of the shocked LH wave, transforming the LH shock into a nonlinear LH wave. The oscillations of the electrostatic potential have a larger amplitude and wavelength in the magnetized plasma than in an unmagnetized one with otherwise identical conditions. The energy loss to the drifting electrons leads to a noticeable slowdown of the LH shock compared to that in an unmagnetized plasma.},
doi = {10.1063/1.4953568},
journal = {Physics of Plasmas},
number = 6,
volume = 23,
place = {United States},
year = 2016,
month = 6
}
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