Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Tearing mode dynamics and locking in the presence of external magnetic perturbations
KTH, School of Electrical Engineering (EES), Fusion Plasma Physics. (Fusion Plasma Physics)ORCID iD: 0000-0002-6554-9681
(MST, UW-Madison)
KTH, School of Electrical Engineering (EES), Fusion Plasma Physics. (Fusion Plasma Physics)ORCID iD: 0000-0002-9546-4494
Show others and affiliations
2016 (English)In: Physics of Plasmas, ISSN 1070-664X, E-ISSN 1089-7674, Vol. 23, 062504- p.Article in journal (Refereed) Published
Abstract [en]

In normal operation, Madison Symmetric Torus (MST) [R. N. Dexter et al., Fusion Technol. 19, 131 (1991)] reversed-field pinch plasmas exhibit several rotating tearing modes (TMs). Application of a resonant magnetic perturbation (RMP) results in braking of mode rotation and, if the perturbation amplitude is sufficiently high, in a wall-locked state. The coils that produce the magnetic perturbation in MST give rise to RMPs with several toroidal harmonics. As a result, simultaneous deceleration of all modes is observed. The measured TM dynamics is shown to be in qualitative agreement with a magnetohydrodynamical model of the RMP interaction with the TM [R. Fitzpatrick, Nucl. Fusion 33, 1049 (1993)] adapted to MST. To correctly model the TM dynamics, the electromagnetic torque acting on several TMs is included. Quantitative agreement of the TM slowing-down time was obtained for a kinematic viscosity in the order of ν≈10–20 m2/s. Analysis of discharges with different plasma densities shows an increase of the locking threshold with increasing density. Modeling results show good agreement with the experimental trend, assuming a density-independent kinematic viscosity. Comparison of the viscosity estimates in this paper to those made previously with other techniques in MST plasmas suggests the possibility that the RMP technique may allow for estimates of the viscosity over a broad range of plasmas in MST and other devices.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2016. Vol. 23, 062504- p.
Keyword [en]
Tearing mode, viscosity, locking, RFP, RMP, MST, magnetic perturbation, fusion, plasma
National Category
Natural Sciences
Research subject
Physics
Identifiers
URN: urn:nbn:se:kth:diva-194184DOI: 10.1063/1.4953438ISI: 000379172200055Scopus ID: 2-s2.0-84974628204OAI: oai:DiVA.org:kth-194184DiVA: diva2:1038619
Note

QC 20161019

Available from: 2016-10-19 Created: 2016-10-19 Last updated: 2017-02-24Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Fridström, RichardLorenzo, FrassinettiBrunsell, Per
By organisation
Fusion Plasma Physics
In the same journal
Physics of Plasmas
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 131 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf