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Title: Transport due to rotational pumping

Abstract

An effect which we call rotational pumping (by analogy with magnetic pumping) causes cross-field transport in nonneutral plasmas when the end confinement potentials are non-axisymmetric. Because the Debye length is small the asymmetries are screened out within the plasma, but cause the surface of the plasma to distort. As a flux tube of plasma undergoes ExB drift rotation about the center of the column, the length of the tube oscillates about some mean value and the P parallel dV work produces a corresponding oscillation in T parallel. In turn the collisional relaxation of T parallel toward T perpendicular produces a slow disspiation of electrostatic energy into heat and a consequent radial expansion (cross-field transport) of the plasma. Detailed comparisons between theory and experiment have been made for the case where the asymmetry is produced by displacing the column off-axis, that is, by creating an m=1 diocotron mode (see paper by Cluggish and Driscoll in these proceedings). The theory is generalized to include time dependent asymmetries. For the case where the asymmetry is a traveling wave that rotates faster than the ExB drift rotation of the plasma the particle flux is directed radially inward.

Authors:
;  [1]
  1. Physics Department, University of California at San Diego, La Jolla, CA 92093 (United States)
Publication Date:
OSTI Identifier:
21153811
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 331; Journal Issue: 1; Conference: Non-neutral plasma physics II: Berkeley workshop on non-neutral plasmas in traps, Berkeley, CA (United States), 17-20 Jul 1994; Other Information: DOI: 10.1063/1.47902; (c) 1995 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ASYMMETRY; AXIAL SYMMETRY; CHARGED-PARTICLE TRANSPORT; COMPARATIVE EVALUATIONS; DEBYE LENGTH; ELECTROMAGNETIC FIELDS; PLASMA; PLASMA CONFINEMENT; PLASMA DRIFT; PLASMA EXPANSION; PLASMA WAVES; POTENTIALS; PUMPING; RELAXATION; ROTATION; TIME DEPENDENCE; TRAVELLING WAVES

Citation Formats

Crooks, S M, and O'Neil, T M. Transport due to rotational pumping. United States: N. p., 1995. Web. doi:10.1063/1.47902.
Crooks, S M, & O'Neil, T M. Transport due to rotational pumping. United States. doi:10.1063/1.47902.
Crooks, S M, and O'Neil, T M. Sat . "Transport due to rotational pumping". United States. doi:10.1063/1.47902.
@article{osti_21153811,
title = {Transport due to rotational pumping},
author = {Crooks, S M and O'Neil, T M},
abstractNote = {An effect which we call rotational pumping (by analogy with magnetic pumping) causes cross-field transport in nonneutral plasmas when the end confinement potentials are non-axisymmetric. Because the Debye length is small the asymmetries are screened out within the plasma, but cause the surface of the plasma to distort. As a flux tube of plasma undergoes ExB drift rotation about the center of the column, the length of the tube oscillates about some mean value and the P parallel dV work produces a corresponding oscillation in T parallel. In turn the collisional relaxation of T parallel toward T perpendicular produces a slow disspiation of electrostatic energy into heat and a consequent radial expansion (cross-field transport) of the plasma. Detailed comparisons between theory and experiment have been made for the case where the asymmetry is produced by displacing the column off-axis, that is, by creating an m=1 diocotron mode (see paper by Cluggish and Driscoll in these proceedings). The theory is generalized to include time dependent asymmetries. For the case where the asymmetry is a traveling wave that rotates faster than the ExB drift rotation of the plasma the particle flux is directed radially inward.},
doi = {10.1063/1.47902},
journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 331,
place = {United States},
year = {1995},
month = {4}
}