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Title: Coaxial discharge with axial magnetic field: Demonstration that the Boltzmann relation for electrons generally does not hold in magnetized plasmas

Abstract

A one-dimensional two-fluid model is used to describe the quasineutral plasma of a discharge formed between coaxial cylinders under the influence of an axial magnetic field. The geometry treated in this paper is symmetric about the z-axis and is radially varying. The nested cylinders are necessarily different in size, leading to a potential difference between the sheath edges of the discharge plasma. This can be removed by applying a strong enough magnetic field, which also has the effect of flattening the potential profile, i.e., reducing the electric field in the plasma volume. In a previous publication [T. M. G. Zimmermann et al., Phys. Plasmas 16, 043501 (2009)], the authors examined the validity of the Boltzmann relation for electrons when applied to a similar geometry. When the magnetic field becomes strong enough to affect the electron flow in the radial direction, this expression breaks down. It was further discovered that certain situations require a self-consistent treatment of magnetic fields, since significant azimuthal currents can arise in such geometries. This work is applied and extended to offer a complete description of the electron density.

Authors:
;  [1];  [1]
  1. Blackett Laboratory, Imperial College, Prince Consort Road, London SW7 2BW (United Kingdom)
Publication Date:
OSTI Identifier:
21347113
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 17; Journal Issue: 2; Other Information: DOI: 10.1063/1.3299390; (c) 2010 American Institute of Physics; Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ELECTRIC DISCHARGES; ELECTRON DENSITY; ELECTRONS; MAGNETIC FIELDS; PLASMA; PLASMA SHEATH; PLASMA SIMULATION; ELEMENTARY PARTICLES; FERMIONS; LEPTONS; SIMULATION

Citation Formats

Zimmermann, T M. G., Coppins, M, Allen, J E, and University College, Oxford OX1 4BH. Coaxial discharge with axial magnetic field: Demonstration that the Boltzmann relation for electrons generally does not hold in magnetized plasmas. United States: N. p., 2010. Web. doi:10.1063/1.3299390.
Zimmermann, T M. G., Coppins, M, Allen, J E, & University College, Oxford OX1 4BH. Coaxial discharge with axial magnetic field: Demonstration that the Boltzmann relation for electrons generally does not hold in magnetized plasmas. United States. doi:10.1063/1.3299390.
Zimmermann, T M. G., Coppins, M, Allen, J E, and University College, Oxford OX1 4BH. Mon . "Coaxial discharge with axial magnetic field: Demonstration that the Boltzmann relation for electrons generally does not hold in magnetized plasmas". United States. doi:10.1063/1.3299390.
@article{osti_21347113,
title = {Coaxial discharge with axial magnetic field: Demonstration that the Boltzmann relation for electrons generally does not hold in magnetized plasmas},
author = {Zimmermann, T M. G. and Coppins, M and Allen, J E and University College, Oxford OX1 4BH},
abstractNote = {A one-dimensional two-fluid model is used to describe the quasineutral plasma of a discharge formed between coaxial cylinders under the influence of an axial magnetic field. The geometry treated in this paper is symmetric about the z-axis and is radially varying. The nested cylinders are necessarily different in size, leading to a potential difference between the sheath edges of the discharge plasma. This can be removed by applying a strong enough magnetic field, which also has the effect of flattening the potential profile, i.e., reducing the electric field in the plasma volume. In a previous publication [T. M. G. Zimmermann et al., Phys. Plasmas 16, 043501 (2009)], the authors examined the validity of the Boltzmann relation for electrons when applied to a similar geometry. When the magnetic field becomes strong enough to affect the electron flow in the radial direction, this expression breaks down. It was further discovered that certain situations require a self-consistent treatment of magnetic fields, since significant azimuthal currents can arise in such geometries. This work is applied and extended to offer a complete description of the electron density.},
doi = {10.1063/1.3299390},
journal = {Physics of Plasmas},
issn = {1070-664X},
number = 2,
volume = 17,
place = {United States},
year = {2010},
month = {2}
}