DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Magnetic and velocity fluctuations from nonlinearly coupled tearing modes in the reversed field pinch with and without the reversal surface

Abstract

Here, we investigate the role of poloidal mode number m = 0 fluctuations on m = 1 velocity and magnetic field fluctuations in the Reversed Field Pinch (RFP). Removing the m = 0 resonant surface in the Madison Symmetric Torus (MST), results in suppressed m = 0 activity without a reduction in m = 1 magnetic activity. However, the m = 1 velocity fluctuations and fluctuation-induced mean emf are reduced as m = 0 modes are suppressed. Velocity fluctuations are measured directly using fast Doppler spectroscopy. Similar results are seen in visco-resistive MHD simulation with the DEBS code. An artificial line-averaged velocity diagnostic is developed for DEBS simulations to facilitate direct comparisons with experimental measurements. The sensitivity of the m = 1 velocity fluctuations and corresponding emf to changes in m = 0 mode activity is a feature of tearing modes in the nonlinear regime with a spectrum of interacting modes. These results have implications for RFP sustainment strategies and inform our understanding of the role of magnetic turbulence in astrophysical contexts

Authors:
 [1];  [1];  [2]; ORCiD logo [2]; ORCiD logo [2]
  1. Wheaton College, Wheaton, IL (United States)
  2. Univ. of Wisconsin - Madison, Madison, WI (United States)
Publication Date:
Research Org.:
Univ. of Wisconsin - Madison, Madison, WI (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
OSTI Identifier:
1474288
Alternate Identifier(s):
OSTI ID: 1373445
Grant/Contract Number:  
FC02-05ER54814
Resource Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 8; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Craig, D., Martin, D., Den Hartog, D. J., Nornberg, M. D., and Reusch, J. A. Magnetic and velocity fluctuations from nonlinearly coupled tearing modes in the reversed field pinch with and without the reversal surface. United States: N. p., 2017. Web. doi:10.1063/1.4996907.
Craig, D., Martin, D., Den Hartog, D. J., Nornberg, M. D., & Reusch, J. A. Magnetic and velocity fluctuations from nonlinearly coupled tearing modes in the reversed field pinch with and without the reversal surface. United States. https://doi.org/10.1063/1.4996907
Craig, D., Martin, D., Den Hartog, D. J., Nornberg, M. D., and Reusch, J. A. Tue . "Magnetic and velocity fluctuations from nonlinearly coupled tearing modes in the reversed field pinch with and without the reversal surface". United States. https://doi.org/10.1063/1.4996907. https://www.osti.gov/servlets/purl/1474288.
@article{osti_1474288,
title = {Magnetic and velocity fluctuations from nonlinearly coupled tearing modes in the reversed field pinch with and without the reversal surface},
author = {Craig, D. and Martin, D. and Den Hartog, D. J. and Nornberg, M. D. and Reusch, J. A.},
abstractNote = {Here, we investigate the role of poloidal mode number m = 0 fluctuations on m = 1 velocity and magnetic field fluctuations in the Reversed Field Pinch (RFP). Removing the m = 0 resonant surface in the Madison Symmetric Torus (MST), results in suppressed m = 0 activity without a reduction in m = 1 magnetic activity. However, the m = 1 velocity fluctuations and fluctuation-induced mean emf are reduced as m = 0 modes are suppressed. Velocity fluctuations are measured directly using fast Doppler spectroscopy. Similar results are seen in visco-resistive MHD simulation with the DEBS code. An artificial line-averaged velocity diagnostic is developed for DEBS simulations to facilitate direct comparisons with experimental measurements. The sensitivity of the m = 1 velocity fluctuations and corresponding emf to changes in m = 0 mode activity is a feature of tearing modes in the nonlinear regime with a spectrum of interacting modes. These results have implications for RFP sustainment strategies and inform our understanding of the role of magnetic turbulence in astrophysical contexts},
doi = {10.1063/1.4996907},
journal = {Physics of Plasmas},
number = 8,
volume = 24,
place = {United States},
year = {Tue Aug 01 00:00:00 EDT 2017},
month = {Tue Aug 01 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 4 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

First charge exchange recombination spectroscopy and motional Stark effect results from the Madison Symmetric Torus reversed field pinch
journal, January 2001

  • Craig, D.; Den Hartog, D. J.; Fiksel, G.
  • Review of Scientific Instruments, Vol. 72, Issue 1
  • DOI: 10.1063/1.1319606

Measurement of nonlinear mode coupling of tearing fluctuations
journal, July 1992


Effect of Collisionality and Diamagnetism on the Plasma Dynamo
journal, August 1995


Modeling fast charge exchange recombination spectroscopy measurements from the Madison Symmetric Torus
journal, October 2006

  • Gangadhara, S.; Craig, D.; Ennis, D. A.
  • Review of Scientific Instruments, Vol. 77, Issue 10
  • DOI: 10.1063/1.2219412

The Hall dynamo effect and nonlinear mode coupling during sawtooth magnetic reconnection
journal, November 2006

  • Ding, W. X.; Brower, D. L.; Deng, B. H.
  • Physics of Plasmas, Vol. 13, Issue 11
  • DOI: 10.1063/1.2363353

Turbulent transport reduction by E   B velocity shear during edge plasma biasing: recent experimental results
journal, March 2003


Mean magnetic field profiles and their dynamics in reversed field pinches
journal, October 1989


Momentum Transport from Nonlinear Mode Coupling of Magnetic Fluctuations
journal, October 2000


The Madison Symmetric Torus
journal, January 1991

  • Dexter, R. N.; Kerst, D. W.; Lovell, T. W.
  • Fusion Technology, Vol. 19, Issue 1
  • DOI: 10.13182/FST91-A29322

High throughput spectrometer for fast localized Doppler measurements
journal, January 2007

  • Craig, D.; Den Hartog, D. J.; Ennis, D. A.
  • Review of Scientific Instruments, Vol. 78, Issue 1
  • DOI: 10.1063/1.2424450

Measurements of the momentum and current transport from tearing instability in the Madison Symmetric Torus reversed-field pinch
journal, May 2009

  • Kuritsyn, A.; Fiksel, G.; Almagri, A. F.
  • Physics of Plasmas, Vol. 16, Issue 5
  • DOI: 10.1063/1.3090325

Nonlinear dynamics of field maintenance and quasiperiodic relaxation in reversed‐field pinches
journal, March 1991

  • Ho, Y. L.; Craddock, G. G.
  • Physics of Fluids B: Plasma Physics, Vol. 3, Issue 3
  • DOI: 10.1063/1.859868

Dynamo-free plasma in the reversed field pinch
journal, May 2004

  • Anderson, J. K.; Biewer, T. M.; Forest, C. B.
  • Physics of Plasmas, Vol. 11, Issue 5
  • DOI: 10.1063/1.1697399

First-order finite-Larmor-radius fluid modeling of tearing and relaxation in a plasma pinch
journal, May 2012

  • King, J. R.; Sovinec, C. R.; Mirnov, V. V.
  • Physics of Plasmas, Vol. 19, Issue 5
  • DOI: 10.1063/1.3695346

Semi-implicit magnetohydrodynamic calculations
journal, June 1987


Momentum transport and flow damping in the reversed-field pinch plasma
journal, November 1998

  • Almagri, A. F.; Chapman, J. T.; Chiang, C. S.
  • Physics of Plasmas, Vol. 5, Issue 11
  • DOI: 10.1063/1.873118

Measurement of core velocity fluctuations and the dynamo in a reversed-field pinch
journal, May 1999

  • Den Hartog, D. J.; Chapman, J. T.; Craig, D.
  • Physics of Plasmas, Vol. 6, Issue 5
  • DOI: 10.1063/1.873439

Local measurements of tearing mode flows and the magnetohydrodynamic dynamo in the Madison Symmetric Torus reversed-field pinch
journal, August 2010

  • Ennis, D. A.; Craig, D.; Gangadhara, S.
  • Physics of Plasmas, Vol. 17, Issue 8
  • DOI: 10.1063/1.3458667

Works referencing / citing this record:

Role of resistivity and viscosity in the excitation of stable m = 0 modes during the RFP sawtooth crash
journal, November 2018

  • Futch, A. M.; Craig, D.; Hesse, R.
  • Physics of Plasmas, Vol. 25, Issue 11
  • DOI: 10.1063/1.5054578