A current-driven resistive instability and its nonlinear effects in simulations of coaxial helicity injection in a tokamak
Abstract
An instability observed in whole-device, resistive magnetohydrodynamic simulations of the driven phase of coaxial helicity injection in the National Spherical Torus eXperiment is identified as a current-driven resistive mode in an unusual geometry that transiently generates a current sheet. The mode consists of plasma flow velocity and magnetic field eddies in a tube aligned with the magnetic field at the surface of the injected magnetic flux. At low plasma temperatures (~10–20 eV), the mode is benign, but at high temperatures (~100 eV) its amplitude undergoes relaxation oscillations, broadening the layer of injected current and flow at the surface of the injected toroidal flux and background plasma. The poloidal-field structure is affected and the magnetic surface closure is generally prevented while the mode undergoes relaxation oscillations during injection. Furthermore, this study describes the mode and uses linearized numerical computations and an analytic slab model to identify the unstable mode.
- Authors:
- Publication Date:
- Research Org.:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1328138
- Alternate Identifier(s):
- OSTI ID: 1343838; OSTI ID: 1421100
- Report Number(s):
- LLNL-JRNL-698022
Journal ID: ISSN 1070-664X
- Grant/Contract Number:
- AC02-05CH11231; AC52-07NA27344; FC02-05ER54813
- Resource Type:
- Published Article
- Journal Name:
- Physics of Plasmas
- Additional Journal Information:
- Journal Name: Physics of Plasmas Journal Volume: 23 Journal Issue: 10; Journal ID: ISSN 1070-664X
- Publisher:
- American Institute of Physics
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION
Citation Formats
Hooper, E. B., and Sovinec, C. R. A current-driven resistive instability and its nonlinear effects in simulations of coaxial helicity injection in a tokamak. United States: N. p., 2016.
Web. doi:10.1063/1.4964292.
Hooper, E. B., & Sovinec, C. R. A current-driven resistive instability and its nonlinear effects in simulations of coaxial helicity injection in a tokamak. United States. https://doi.org/10.1063/1.4964292
Hooper, E. B., and Sovinec, C. R. Sat .
"A current-driven resistive instability and its nonlinear effects in simulations of coaxial helicity injection in a tokamak". United States. https://doi.org/10.1063/1.4964292.
@article{osti_1328138,
title = {A current-driven resistive instability and its nonlinear effects in simulations of coaxial helicity injection in a tokamak},
author = {Hooper, E. B. and Sovinec, C. R.},
abstractNote = {An instability observed in whole-device, resistive magnetohydrodynamic simulations of the driven phase of coaxial helicity injection in the National Spherical Torus eXperiment is identified as a current-driven resistive mode in an unusual geometry that transiently generates a current sheet. The mode consists of plasma flow velocity and magnetic field eddies in a tube aligned with the magnetic field at the surface of the injected magnetic flux. At low plasma temperatures (~10–20 eV), the mode is benign, but at high temperatures (~100 eV) its amplitude undergoes relaxation oscillations, broadening the layer of injected current and flow at the surface of the injected toroidal flux and background plasma. The poloidal-field structure is affected and the magnetic surface closure is generally prevented while the mode undergoes relaxation oscillations during injection. Furthermore, this study describes the mode and uses linearized numerical computations and an analytic slab model to identify the unstable mode.},
doi = {10.1063/1.4964292},
journal = {Physics of Plasmas},
number = 10,
volume = 23,
place = {United States},
year = {Sat Oct 01 00:00:00 EDT 2016},
month = {Sat Oct 01 00:00:00 EDT 2016}
}
https://doi.org/10.1063/1.4964292
Web of Science
Works referenced in this record:
Relaxation of Toroidal Plasma and Generation of Reverse Magnetic Fields
journal, November 1974
- Taylor, J. B.
- Physical Review Letters, Vol. 33, Issue 19
Relaxation and magnetic reconnection in plasmas
journal, July 1986
- Taylor, J. B.
- Reviews of Modern Physics, Vol. 58, Issue 3
The internal magnetic field structures and current density profiles in the Helicity Injected Spherical Torus plasma driven by coaxial helicity injection
journal, July 2003
- Nagata, Masayoshi; Kanki, Takashi; Fukumoto, Naoyuki
- Physics of Plasmas, Vol. 10, Issue 7
Review of spheromak research
journal, June 1994
- Jarboe, T. R.
- Plasma Physics and Controlled Fusion, Vol. 36, Issue 6
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
Sustained Spheromak Physics Experiment (SSPX): design and physics results
journal, October 2012
- Hooper, E. B.; Bulmer, R. H.; Cohen, B. I.
- Plasma Physics and Controlled Fusion, Vol. 54, Issue 11
Current drive experiments in the helicity injected torus (HIT-II)
journal, May 2002
- Redd, A. J.; Nelson, B. A.; Jarboe, T. R.
- Physics of Plasmas, Vol. 9, Issue 5
Coaxial helicity injection in open-flux low-aspect-ratio toroidal discharges
journal, November 2007
- Redd, A. J.; Jarboe, T. R.; Nelson, B. A.
- Physics of Plasmas, Vol. 14, Issue 11
Efficient Generation of Closed Magnetic Flux Surfaces in a Large Spherical Tokamak Using Coaxial Helicity Injection
journal, October 2006
- Raman, R.; Nelson, B. A.; Bell, M. G.
- Physical Review Letters, Vol. 97, Issue 17
Non-inductive plasma start-up on NSTX and projections to NSTX-U using transient CHI
journal, June 2013
- Raman, R.; Mueller, D.; Jardin, S. C.
- Nuclear Fusion, Vol. 53, Issue 7
Nonlinear magnetohydrodynamics simulation using high-order finite elements
journal, March 2004
- Sovinec, C. R.; Glasser, A. H.; Gianakon, T. A.
- Journal of Computational Physics, Vol. 195, Issue 1
Magnetic reconnection process in transient coaxial helicity injection
journal, September 2013
- Ebrahimi, F.; Hooper, E. B.; Sovinec, C. R.
- Physics of Plasmas, Vol. 20, Issue 9
Physics of forced magnetic reconnection in coaxial helicity injection experiments in National Spherical Torus Experiment
journal, May 2014
- Ebrahimi, F.; Raman, R.; Hooper, E. B.
- Physics of Plasmas, Vol. 21, Issue 5
Resistive magnetohydrodynamic simulations of helicity-injected startup plasmas in National Spherical Torus eXperiment
journal, September 2013
- Hooper, E. B.; Sovinec, C. R.; Raman, R.
- Physics of Plasmas, Vol. 20, Issue 9
Magnetic reconnection via current sheets
journal, January 1986
- Biskamp, D.
- Physics of Fluids, Vol. 29, Issue 5
Instability of current sheets and formation of plasmoid chains
journal, October 2007
- Loureiro, N. F.; Schekochihin, A. A.; Cowley, S. C.
- Physics of Plasmas, Vol. 14, Issue 10
Plasmoid instability in high-Lundquist-number magnetic reconnection
journal, May 2013
- Huang, Yi-Min; Bhattacharjee, A.
- Physics of Plasmas, Vol. 20, Issue 5
Plasmoids Formation During Simulations of Coaxial Helicity Injection in the National Spherical Torus Experiment
journal, May 2015
- Ebrahimi, F.; Raman, R.
- Physical Review Letters, Vol. 114, Issue 20
Large-volume flux closure during plasmoid-mediated reconnection in coaxial helicity injection
journal, March 2016
- Ebrahimi, F.; Raman, R.
- Nuclear Fusion, Vol. 56, Issue 4, Article No. 044002
NIMROD resistive magnetohydrodynamic simulations of spheromak physics
journal, March 2008
- Hooper, E. B.; Cohen, B. I.; McLean, H. S.
- Physics of Plasmas, Vol. 15, Issue 3
Steady-state radiative cooling rates for low-density, high-temperature plasmas
journal, November 1977
- Post, D. E.; Jensen, R. V.; Tarter, C. B.
- Atomic Data and Nuclear Data Tables, Vol. 20, Issue 5
The effect of artificial diffusivity on the flute instability
journal, August 2005
- Ryutov, D. D.; Cohen, B. I.; Cohen, R. H.
- Physics of Plasmas, Vol. 12, Issue 8
Effects of line tying on resistive tearing instability in slab geometry
journal, April 2009
- Huang, Yi-Min; Zweibel, Ellen G.
- Physics of Plasmas, Vol. 16, Issue 4
Finite-Resistivity Instabilities of a Sheet Pinch
journal, January 1963
- Furth, Harold P.; Killeen, John; Rosenbluth, Marshall N.
- Physics of Fluids, Vol. 6, Issue 4
Works referencing / citing this record:
Three-dimensional plasmoid-mediated reconnection and the effect of toroidal guide field in simulations of coaxial helicity injection
journal, September 2019
- Ebrahimi, F.
- Physics of Plasmas, Vol. 26, Issue 9
Nonlinear reconnecting edge localized modes in current-carrying plasmas
journal, May 2017
- Ebrahimi, F.
- Physics of Plasmas, Vol. 24, Issue 5
Plasma density injection and flow during coaxial helicity injection in a tokamak
journal, February 2018
- Hooper, E. B.
- Physics of Plasmas, Vol. 25, Issue 2