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Title: Particle dynamics in asymmetry-induced transport

Abstract

The particle dynamics of asymmetry-induced transport are studied using a single-particle computer simulation. For the case of a helical asymmetry with axial and azimuthal wavenumbers (k,l) and with periodic boundary conditions, behaviors consistent with analytical theory are observed. For the typical experimental case of a standing wave asymmetry, the code reveals dynamical behaviors not included in the analytical theory of this transport. The resonances associated with the two constituent helical waves typically overlap and produce a region of stochastic motion. In addition, particles near the radius where the asymmetry frequency {omega} matches l times the ExB rotation frequency {omega}{sub R} can be trapped in the potential of the applied asymmetry and confined to one end of the device. Both behaviors are associated with large radial excursions and mainly affect particles with low velocities, i.e., v{sub z}<2{omega}{sub T}/k, where {omega}{sub T} is the trapping frequency. For the case of a helical asymmetry with specularly reflecting boundaries, large radial excursions are observed for all velocities near the radius, where {omega}=l{omega}{sub R}. Minor modifications to these results are observed when the code is run with realistic end potentials.

Authors:
 [1]
  1. Occidental College, Physics Department, Los Angeles, California 90041 (United States)
Publication Date:
OSTI Identifier:
20960090
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 14; Journal Issue: 1; Other Information: DOI: 10.1063/1.2424431; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ASYMMETRY; BOUNDARY CONDITIONS; COMPUTERIZED SIMULATION; ELECTROMAGNETIC FIELDS; EXCURSIONS; PARTICLES; PERIODICITY; PLASMA; PLASMA SIMULATION; RESONANCE; STANDING WAVES; STOCHASTIC PROCESSES; TRAPPING; TRAPS

Citation Formats

Eggleston, D. L. Particle dynamics in asymmetry-induced transport. United States: N. p., 2007. Web. doi:10.1063/1.2424431.
Eggleston, D. L. Particle dynamics in asymmetry-induced transport. United States. doi:10.1063/1.2424431.
Eggleston, D. L. Mon . "Particle dynamics in asymmetry-induced transport". United States. doi:10.1063/1.2424431.
@article{osti_20960090,
title = {Particle dynamics in asymmetry-induced transport},
author = {Eggleston, D. L.},
abstractNote = {The particle dynamics of asymmetry-induced transport are studied using a single-particle computer simulation. For the case of a helical asymmetry with axial and azimuthal wavenumbers (k,l) and with periodic boundary conditions, behaviors consistent with analytical theory are observed. For the typical experimental case of a standing wave asymmetry, the code reveals dynamical behaviors not included in the analytical theory of this transport. The resonances associated with the two constituent helical waves typically overlap and produce a region of stochastic motion. In addition, particles near the radius where the asymmetry frequency {omega} matches l times the ExB rotation frequency {omega}{sub R} can be trapped in the potential of the applied asymmetry and confined to one end of the device. Both behaviors are associated with large radial excursions and mainly affect particles with low velocities, i.e., v{sub z}<2{omega}{sub T}/k, where {omega}{sub T} is the trapping frequency. For the case of a helical asymmetry with specularly reflecting boundaries, large radial excursions are observed for all velocities near the radius, where {omega}=l{omega}{sub R}. Minor modifications to these results are observed when the code is run with realistic end potentials.},
doi = {10.1063/1.2424431},
journal = {Physics of Plasmas},
number = 1,
volume = 14,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}