Electrostatically driven helical plasma state
Abstract
A novel plasma state has been found in the presence of a uniformly applied axial magnetic field in periodic cylindrical geometry. This state is driven electrostatically by helical electrodes, providing a driving field that depends on the radius and mθ−nζ, where θ is the poloidal angle and ζ=z/R is the toroidal angle. We focus on m=n=1. The radial magnetic field at the wall is taken to be zero. With weak driving, the resulting distortion is very small, but for stronger driving, the mean field of the state has field line safety factor q0(r) just above the pitch of the electrodes m∕n = 1 except near the edge, where q0 increases monotonically. This state is characterized as a single helicity Ohmic equilibrium with the helical symmetry of the applied field. The plasma appears to be close to force-free in the interior, but current density crosses the magnetic flux surfaces near the edge, where current must enter and exit through the helical electrodes. This perpendicular current density drives large helical plasma flows. The sensitivity of this state to flow boundary conditions, plasma resistivity profile, the strength of electrostatic driving, and parameters such as the loop voltage and the Lundquist number is explored. The magneticmore »
- Authors:
- Publication Date:
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1375640
- Grant/Contract Number:
- AR000067
- Resource Type:
- Publisher's Accepted Manuscript
- Journal Name:
- Physics of Plasmas
- Additional Journal Information:
- Journal Name: Physics of Plasmas Journal Volume: 24 Journal Issue: 5; Journal ID: ISSN 1070-664X
- Publisher:
- American Institute of Physics
- Country of Publication:
- United States
- Language:
- English
Citation Formats
Akçay, Cihan, Finn, John M., Nebel, Richard A., and Barnes, Daniel C. Electrostatically driven helical plasma state. United States: N. p., 2017.
Web. doi:10.1063/1.4981384.
Akçay, Cihan, Finn, John M., Nebel, Richard A., & Barnes, Daniel C. Electrostatically driven helical plasma state. United States. https://doi.org/10.1063/1.4981384
Akçay, Cihan, Finn, John M., Nebel, Richard A., and Barnes, Daniel C. Mon .
"Electrostatically driven helical plasma state". United States. https://doi.org/10.1063/1.4981384.
@article{osti_1375640,
title = {Electrostatically driven helical plasma state},
author = {Akçay, Cihan and Finn, John M. and Nebel, Richard A. and Barnes, Daniel C.},
abstractNote = {A novel plasma state has been found in the presence of a uniformly applied axial magnetic field in periodic cylindrical geometry. This state is driven electrostatically by helical electrodes, providing a driving field that depends on the radius and mθ−nζ, where θ is the poloidal angle and ζ=z/R is the toroidal angle. We focus on m=n=1. The radial magnetic field at the wall is taken to be zero. With weak driving, the resulting distortion is very small, but for stronger driving, the mean field of the state has field line safety factor q0(r) just above the pitch of the electrodes m∕n = 1 except near the edge, where q0 increases monotonically. This state is characterized as a single helicity Ohmic equilibrium with the helical symmetry of the applied field. The plasma appears to be close to force-free in the interior, but current density crosses the magnetic flux surfaces near the edge, where current must enter and exit through the helical electrodes. This perpendicular current density drives large helical plasma flows. The sensitivity of this state to flow boundary conditions, plasma resistivity profile, the strength of electrostatic driving, and parameters such as the loop voltage and the Lundquist number is explored. The magnetic helicity is calculated for both the transient period and time-asymptotic state. Possible applications to current drive in toroidal confinement devices and to electrical transformers are discussed.},
doi = {10.1063/1.4981384},
journal = {Physics of Plasmas},
number = 5,
volume = 24,
place = {United States},
year = {Mon Apr 24 00:00:00 EDT 2017},
month = {Mon Apr 24 00:00:00 EDT 2017}
}
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Works referenced in this record:
Formation and sustainment of electrostatically driven spheromaks in the resistive magnetohydrodynamic model
journal, February 2001
- Sovinec, C. R.; Finn, J. M.; del-Castillo-Negrete, D.
- Physics of Plasmas, Vol. 8, Issue 2
The NIMROD code: a new approach to numerical plasma physics
journal, January 1999
- Glasser, A. H.; Sovinec, C. R.; Nebel, R. A.
- Plasma Physics and Controlled Fusion, Vol. 41, Issue 3A
Magnetic islands at the field reversal surface in reversed field pinches
journal, January 1986
- Pinsker, R. I.; Reiman, A. H.
- Physics of Fluids, Vol. 29, Issue 3
Single-Helical-Axis States in Reversed-Field-Pinch Plasmas
journal, July 2008
- Lorenzini, R.; Terranova, D.; Alfier, A.
- Physical Review Letters, Vol. 101, Issue 2
The topological properties of magnetic helicity
journal, October 1984
- Berger, Mitchell A.; Field, George B.
- Journal of Fluid Mechanics, Vol. 147, Issue -1
Error field penetration and locking to the backward propagating wave
journal, December 2015
- Finn, John M.; Cole, Andrew J.; Brennan, Dylan P.
- Physics of Plasmas, Vol. 22, Issue 12
Electrostatic mode associated with the pinch velocity in reversed field pinch simulations
journal, December 2008
- Delzanno, Gian Luca; Chacón, Luis; Finn, John M.
- Physics of Plasmas, Vol. 15, Issue 12
Effect of a gradient in parallel current on field error profiles in a reversed‐field pinch
journal, February 1991
- Sidikman, K. L.; Callen, J. D.; Nebel, R. A.
- Physics of Fluids B: Plasma Physics, Vol. 3, Issue 2
Chaotic Scattering and Self-Organization in Spheromak Sustainment
journal, November 2000
- Finn, John M.; Sovinec, Carl R.; del-Castillo-Negrete, Diego
- Physical Review Letters, Vol. 85, Issue 21
Self-organized helical equilibria as a new paradigm for ohmically heated fusion plasmas
journal, June 2009
- Lorenzini, R.; Martines, E.; Piovesan, P.
- Nature Physics, Vol. 5, Issue 8
Mode locking in tokamaks
journal, December 1990
- Nave, M. F. F.; Wesson, J. A.
- Nuclear Fusion, Vol. 30, Issue 12
The Magnetic Field of Sunspots
journal, November 1933
- Cowling, T. G.
- Monthly Notices of the Royal Astronomical Society, Vol. 94, Issue 1
Relaxation and magnetic reconnection in plasmas
journal, July 1986
- Taylor, J. B.
- Reviews of Modern Physics, Vol. 58, Issue 3
Anomalous current penetration and oscillating current drive in tokamaks
journal, January 1987
- Finn, John M.; Antonsen, Thomas M.
- Physics of Fluids, Vol. 30, Issue 8
Error Field Amplification and Rotation Damping in Tokamak Plasmas
journal, May 2001
- Boozer, Allen H.
- Physical Review Letters, Vol. 86, Issue 22
Semi-implicit magnetohydrodynamic calculations
journal, June 1987
- Schnack, D. D.; Barnes, D. C.; Mikic, Z.
- Journal of Computational Physics, Vol. 70, Issue 2
From Lorenz to Coulomb and other explicit gauge transformations
journal, September 2002
- Jackson, J. D.
- American Journal of Physics, Vol. 70, Issue 9
Single and multiple helicity Ohmic states in reversed‐field pinches
journal, May 1992
- Finn, John M.; Nebel, Rick; Bathke, Charles
- Physics of Fluids B: Plasma Physics, Vol. 4, Issue 5
Review of spheromak research
journal, June 1994
- Jarboe, T. R.
- Plasma Physics and Controlled Fusion, Vol. 36, Issue 6