A current-driven resistive instability and its nonlinear effects in simulations of coaxial helicity injection in a tokamak

Hooper, E. B.; Sovinec, C. R.

doi:10.1063/1.4964292

Title: A current-driven resistive instability and its nonlinear effects in simulations of coaxial helicity injection in a tokamak

Journal Article · Thu Oct 06 04:00:00 UTC 2016 · Physics of Plasmas

DOI: https://doi.org/10.1063/1.4964292 · OSTI ID:1328138

Hooper, E. B.; Sovinec, C. R.

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. This study describes the mode and uses linearized numerical computations and an analytic slab model to identify the unstable mode.

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Sponsoring Organization:: USDOE

Grant/Contract Number:: AC02-05CH11231; AC52-07NA27344; FC02-05ER54813

OSTI ID:: 1328138

Journal Information:: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 23; ISSN 1070-664X

Publisher:: American Institute of PhysicsCopyright Statement

Country of Publication:: United States

Language:: English

References (24)

Steady-state radiative cooling rates for low-density, high-temperature plasmas Post, D. E.; Jensen, R. V.; Tarter, C. B. Atomic Data and Nuclear Data Tables, Vol. 20, Issue 5 https://doi.org/10.1016/0092-640X(77)90026-2	journal	November 1977
Nonlinear magnetohydrodynamics simulation using high-order finite elements Sovinec, C. R.; Glasser, A. H.; Gianakon, T. A. Journal of Computational Physics, Vol. 195, Issue 1 https://doi.org/10.1016/j.jcp.2003.10.004	journal	March 2004
Formation and sustainment of electrostatically driven spheromaks in the resistive magnetohydrodynamic model Sovinec, C. R.; Finn, J. M.; del-Castillo-Negrete, D. Physics of Plasmas, Vol. 8, Issue 2 https://doi.org/10.1063/1.1335585	journal	February 2001
Current drive experiments in the helicity injected torus (HIT-II) Redd, A. J.; Nelson, B. A.; Jarboe, T. R. Physics of Plasmas, Vol. 9, Issue 5 https://doi.org/10.1063/1.1448832	journal	May 2002
The internal magnetic field structures and current density profiles in the Helicity Injected Spherical Torus plasma driven by coaxial helicity injection Nagata, Masayoshi; Kanki, Takashi; Fukumoto, Naoyuki Physics of Plasmas, Vol. 10, Issue 7 https://doi.org/10.1063/1.1580815	journal	July 2003
Finite-Resistivity Instabilities of a Sheet Pinch Furth, Harold P.; Killeen, John; Rosenbluth, Marshall N. Physics of Fluids, Vol. 6, Issue 4 https://doi.org/10.1063/1.1706761	journal	January 1963
The effect of artificial diffusivity on the flute instability Ryutov, D. D.; Cohen, B. I.; Cohen, R. H. Physics of Plasmas, Vol. 12, Issue 8 https://doi.org/10.1063/1.2030367	journal	August 2005
Instability of current sheets and formation of plasmoid chains Loureiro, N. F.; Schekochihin, A. A.; Cowley, S. C. Physics of Plasmas, Vol. 14, Issue 10 https://doi.org/10.1063/1.2783986	journal	October 2007
Coaxial helicity injection in open-flux low-aspect-ratio toroidal discharges Redd, A. J.; Jarboe, T. R.; Nelson, B. A. Physics of Plasmas, Vol. 14, Issue 11 https://doi.org/10.1063/1.2800863	journal	November 2007
NIMROD resistive magnetohydrodynamic simulations of spheromak physics Hooper, E. B.; Cohen, B. I.; McLean, H. S. Physics of Plasmas, Vol. 15, Issue 3 https://doi.org/10.1063/1.2890772	journal	March 2008
Effects of line tying on resistive tearing instability in slab geometry Huang, Yi-Min; Zweibel, Ellen G. Physics of Plasmas, Vol. 16, Issue 4 https://doi.org/10.1063/1.3103789	journal	April 2009
Plasmoid instability in high-Lundquist-number magnetic reconnection Huang, Yi-Min; Bhattacharjee, A. Physics of Plasmas, Vol. 20, Issue 5 https://doi.org/10.1063/1.4802941	journal	May 2013
Magnetic reconnection process in transient coaxial helicity injection Ebrahimi, F.; Hooper, E. B.; Sovinec, C. R. Physics of Plasmas, Vol. 20, Issue 9 https://doi.org/10.1063/1.4821974	journal	September 2013
Resistive magnetohydrodynamic simulations of helicity-injected startup plasmas in National Spherical Torus eXperiment Hooper, E. B.; Sovinec, C. R.; Raman, R. Physics of Plasmas, Vol. 20, Issue 9 https://doi.org/10.1063/1.4821977	journal	September 2013
Physics of forced magnetic reconnection in coaxial helicity injection experiments in National Spherical Torus Experiment Ebrahimi, F.; Raman, R.; Hooper, E. B. Physics of Plasmas, Vol. 21, Issue 5 https://doi.org/10.1063/1.4875337	journal	May 2014
Magnetic reconnection via current sheets Biskamp, D. Physics of Fluids, Vol. 29, Issue 5 https://doi.org/10.1063/1.865670	journal	January 1986
Non-inductive plasma start-up on NSTX and projections to NSTX-U using transient CHI Raman, R.; Mueller, D.; Jardin, S. C. Nuclear Fusion, Vol. 53, Issue 7 https://doi.org/10.1088/0029-5515/53/7/073017	journal	June 2013
Large-volume flux closure during plasmoid-mediated reconnection in coaxial helicity injection Ebrahimi, F.; Raman, R. Nuclear Fusion, Vol. 56, Issue 4, Article No. 044002 https://doi.org/10.1088/0029-5515/56/4/044002	journal	March 2016
Review of spheromak research Jarboe, T. R. Plasma Physics and Controlled Fusion, Vol. 36, Issue 6 https://doi.org/10.1088/0741-3335/36/6/002	journal	June 1994
Sustained Spheromak Physics Experiment (SSPX): design and physics results Hooper, E. B.; Bulmer, R. H.; Cohen, B. I. Plasma Physics and Controlled Fusion, Vol. 54, Issue 11 https://doi.org/10.1088/0741-3335/54/11/113001	journal	October 2012
Plasmoids Formation During Simulations of Coaxial Helicity Injection in the National Spherical Torus Experiment Ebrahimi, F.; Raman, R. Physical Review Letters, Vol. 114, Issue 20 https://doi.org/10.1103/PhysRevLett.114.205003	journal	May 2015
Relaxation of Toroidal Plasma and Generation of Reverse Magnetic Fields Taylor, J. B. Physical Review Letters, Vol. 33, Issue 19 https://doi.org/10.1103/PhysRevLett.33.1139	journal	November 1974
Efficient Generation of Closed Magnetic Flux Surfaces in a Large Spherical Tokamak Using Coaxial Helicity Injection Raman, R.; Nelson, B. A.; Bell, M. G. Physical Review Letters, Vol. 97, Issue 17 https://doi.org/10.1103/PhysRevLett.97.175002	journal	October 2006
Relaxation and magnetic reconnection in plasmas Taylor, J. B. Reviews of Modern Physics, Vol. 58, Issue 3 https://doi.org/10.1103/RevModPhys.58.741	journal	July 1986

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