skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Divertor currents during type-I edge-localized modes on the DIII-D tokamak

Abstract

Measurements of divertor currents on DIII-D lead to new insights in nonlinear ELM dynamics and a possible mechanism to explain their explosive growth. Herein rapidly oscillating currents flowing into the divertor before a significant increase in divertor heat flux occurs are measured with an array of shunted tiles and characterized. Extrapolation results in total n=0 currents of 5-10 kA flowing into a concentric circle near the strike point. The detected Fourier harmonics appear consistent with a mix of low-n modes (n<4) with currents up to 4 kA. A heuristic framework for ELM currents (ECF) is developed based on thermoelectric origin of the tile currents with flow through regions inside of the nominal separatrix and found consistent with the current measurements. A current flow through the confined plasma leading to increased stochasticity and transport at the plasma edge, could provide a mechanism for additional nonlinear growth as sought for in computational ELM simulations. Results also imply that ELM currents may open the possibility to manipulate the ELM character by perturbations through non-axisymmetric divertor bias or tile insulation.

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [4]; ORCiD logo [4]; ORCiD logo [1]; ORCiD logo [4]; ORCiD logo [5]
+ Show Author Affiliations
  1. Univ. of California, San Diego, CA (United States)
  2. General Atomics, San Diego, CA (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  5. Max Planck Inst. for Plasma Physics, Garching (Germany)
Publication Date:
Research Org.:
General Atomics, San Diego, CA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); General Atomics, San Diego, CA (United States). DIII-D National Fusion Facility
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
OSTI Identifier:
1571140
Alternate Identifier(s):
OSTI ID: 1608415; OSTI ID: 1651251
Grant/Contract Number:  
FC02-04ER54698; AC05-00OR22725; FG02-05ER54809; FG02-07ER54917; SC0018030
Resource Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 59; Journal Issue: 12; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ELM; divertor; current; nonlinear

Citation Formats

Knolker, M., Evans, T. E., Wingen, A., Bortolon, A., Laggner, F. M., Moyer, R. A., Nazikian, R., and Zohm, H. Divertor currents during type-I edge-localized modes on the DIII-D tokamak. United States: N. p., 2019. Web. doi:10.1088/1741-4326/ab3e9a.
Copy to clipboard
Knolker, M., Evans, T. E., Wingen, A., Bortolon, A., Laggner, F. M., Moyer, R. A., Nazikian, R., & Zohm, H. Divertor currents during type-I edge-localized modes on the DIII-D tokamak. United States. doi:10.1088/1741-4326/ab3e9a.
Copy to clipboard
Knolker, M., Evans, T. E., Wingen, A., Bortolon, A., Laggner, F. M., Moyer, R. A., Nazikian, R., and Zohm, H. Fri . "Divertor currents during type-I edge-localized modes on the DIII-D tokamak". United States. doi:10.1088/1741-4326/ab3e9a. https://www.osti.gov/servlets/purl/1571140.
Copy to clipboard
@article{osti_1571140,
title = {Divertor currents during type-I edge-localized modes on the DIII-D tokamak},
author = {Knolker, M. and Evans, T. E. and Wingen, A. and Bortolon, A. and Laggner, F. M. and Moyer, R. A. and Nazikian, R. and Zohm, H.},
abstractNote = {Measurements of divertor currents on DIII-D lead to new insights in nonlinear ELM dynamics and a possible mechanism to explain their explosive growth. Herein rapidly oscillating currents flowing into the divertor before a significant increase in divertor heat flux occurs are measured with an array of shunted tiles and characterized. Extrapolation results in total n=0 currents of 5-10 kA flowing into a concentric circle near the strike point. The detected Fourier harmonics appear consistent with a mix of low-n modes (n<4) with currents up to 4 kA. A heuristic framework for ELM currents (ECF) is developed based on thermoelectric origin of the tile currents with flow through regions inside of the nominal separatrix and found consistent with the current measurements. A current flow through the confined plasma leading to increased stochasticity and transport at the plasma edge, could provide a mechanism for additional nonlinear growth as sought for in computational ELM simulations. Results also imply that ELM currents may open the possibility to manipulate the ELM character by perturbations through non-axisymmetric divertor bias or tile insulation.},
doi = {10.1088/1741-4326/ab3e9a},
journal = {Nuclear Fusion},
number = 12,
volume = 59,
place = {United States},
year = {2019},
month = {10}
}
Copy to clipboard
Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI:  10.1088/1741-4326/ab3e9a
Copyright Statement
Other availability
Search WorldCat Search WorldCat to find libraries that may hold this journal
Citation Metrics:
Cited by: 1 work
Citation information provided by
Web of Science
Save / Share:
Export Metadata
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

Works referenced in this record:

Observation of SOL current correlated with MHD activity in NBI heated DIII-D tokamak discharges
journal, September 2004

Solitary magnetic perturbations at the ELM onset
journal, October 2012

Intrinsic Rotation of a Magnetic Island with Finite Width
journal, January 2010

  • Uzawa, Ken; Ishizawa, Akihiro; Nakajima, Noriyoshi
  • Plasma and Fusion Research, Vol. 5
  • DOI: 10.1585/pfr.5.S1016

Scrape-Off-Layer Current Model for Filament Structure Observed during Edge-Localized Modes in the DIII-D Tokamak
journal, May 2008

Divertor power deposition and target current asymmetries during type-I ELMs in ASDEX Upgrade and JET
journal, June 2007

Modeling of stochastic magnetic flux loss from the edge of a poloidally diverted tokamak
journal, December 2002

  • Evans, T. E.; Moyer, R. A.; Monat, P.
  • Physics of Plasmas, Vol. 9, Issue 12
  • DOI: 10.1063/1.1521125

Energy flux to the ASDEX-Upgrade diverter plates determined by thermography and calorimetry
journal, January 1995

The critical point for the onset of divertor energy flux asymmetry in tokamaks
journal, November 1996

Edge localized modes and the pedestal: A model based on coupled peeling–ballooning modes
journal, May 2002

  • Snyder, P. B.; Wilson, H. R.; Ferron, J. R.
  • Physics of Plasmas, Vol. 9, Issue 5
  • DOI: 10.1063/1.1449463

Divertor heat load in ASDEX Upgrade L-mode in presence of external magnetic perturbation
journal, July 2017

  • Faitsch, M.; Sieglin, B.; Eich, T.
  • Plasma Physics and Controlled Fusion, Vol. 59, Issue 9
  • DOI: 10.1088/1361-6587/aa75e7

Evolution of Filament Structures during Edge-Localized Modes in the MAST Tokamak
journal, May 2006

Effect of thermoelectric current splitting on the magnetic topology in DIII-D
journal, April 2011

  • Wingen, A.; Evans, T. E.; Spatschek, K. H.
  • Physics of Plasmas, Vol. 18, Issue 4
  • DOI: 10.1063/1.3571600

A conceptual model of the magnetic topology and nonlinear dynamics of ELMs
journal, June 2009

High resolution numerical studies of separatrix splitting due to non-axisymmetric perturbation in DIII-D
journal, April 2009

Currents in the scrape-off layer of diverted tokamaks
journal, October 1989

Edge-Localized-Mode–Induced Transport of Impurity Density, Energy, and Momentum
journal, June 2005

Experimental signatures of homoclinic tangles in poloidally diverted tokamaks
journal, January 2005

ELM transport in the JET scrape-off layer
journal, October 2007

ELM divertor peak energy fluence scaling to ITER with data from JET, MAST and ASDEX upgrade
journal, August 2017

Explicit calculations of homoclinic tangles in tokamaks
journal, September 2003

  • Roeder, R. K. W.; Rapoport, B. I.; Evans, T. E.
  • Physics of Plasmas, Vol. 10, Issue 9
  • DOI: 10.1063/1.1592515

ELM particle and energy transport in the SOL and divertor of DIII-D
journal, August 2003

  • Fenstermacher, M. E.; Leonard, A. W.; Snyder, P. B.
  • Plasma Physics and Controlled Fusion, Vol. 45, Issue 9
  • DOI: 10.1088/0741-3335/45/9/304

Characteristics of type I ELM energy and particle losses in existing devices and their extrapolation to ITER
journal, August 2003

Homoclinic tangles, bifurcations and edge stochasticity in diverted tokamaks
journal, April 2004

  • Evans, T. E.; Roeder, R. K. W.; Carter, J. A.
  • Contributions to Plasma Physics, Vol. 44, Issue 13
  • DOI: 10.1002/ctpp.200410034

Measurements of non-axisymmetric effects in the DIII-D divertor
journal, April 1995

Electromagnetic ELM and inter-ELM filaments detected in the COMPASS Scrape-Off Layer
journal, August 2017

Electric currents in the scrape-off layer in ASDEX Upgrade
journal, March 2001

Effect of divertor bias on plasma flow in the DIII-D scrape-off layer
journal, May 1992

Edge-localized-modes in tokamaks
journal, September 2014

Submicrosecond laser-filament-assisted corona bursts near a high-voltage electrode
journal, April 2010

  • Sugiyama, Kiyohiro; Fujii, Takashi; Miki, Megumu
  • Physics of Plasmas, Vol. 17, Issue 4
  • DOI: 10.1063/1.3299389

Thermoelectric currents and their role during ELM formation in JET
journal, July 2012

The role of magnetic geometry on the poloidal distribution of ELM-induced peak particle flux at the divertor targets in DIII-D
journal, August 2003

ELM driven divertor target currents on TCV
journal, September 2003

Investigation of the role of pedestal pressure and collisionality on type-I ELM divertor heat loads in DIII-D
journal, July 2018

Numerical Modeling of Edge-Localized-Mode Filaments on Divertor Plates Based on Thermoelectric Currents
journal, April 2010

Imaging divertor strike point splitting in RMP ELM suppression experiments in the DIII-D tokamak
journal, October 2018

  • Moyer, R. A.; Bykov, I.; Orlov, D. M.
  • Review of Scientific Instruments, Vol. 89, Issue 10
  • DOI: 10.1063/1.5038350

Nonlinear excitation of low-n harmonics in reduced magnetohydrodynamic simulations of edge-localized modes
journal, August 2013

  • Krebs, I.; Hölzl, M.; Lackner, K.
  • Physics of Plasmas, Vol. 20, Issue 8
  • DOI: 10.1063/1.4817953

Divertor power and particle fluxes between and during type-I ELMs in the ASDEX Upgrade
journal, July 2008

Impact of plasma response on plasma displacements in DIII-D during application of external 3D perturbations
journal, May 2014

Pedestal performance dependence upon plasma shape in DIII-D
journal, June 2007

Biased electrodes for SOL control in NSTX
journal, June 2009

Principal physics developments evaluated in the ITER design review
journal, May 2009

The X-point scrape-off plasma in jet with L- and H-modes
journal, April 1989

ELM pacing using modulated non-axisymmetric magnetic fields on DIII-D
journal, March 2012

Observation of electric currents in diverted tokamak scrape-off layers
journal, September 1991

Power requirement for accessing the H-mode in ITER
journal, July 2008

  • Martin, Y. R.; Takizuka, T.; Group, the ITPA CDBM H-mode Threshold Data
  • Journal of Physics: Conference Series, Vol. 123
  • DOI: 10.1088/1742-6596/123/1/012033

Divertor bias experiments
journal, April 1995

Progress in the peeling-ballooning model of edge localized modes: Numerical studies of nonlinear dynamics
journal, May 2005

  • Snyder, P. B.; Wilson, H. R.; Xu, X. Q.
  • Physics of Plasmas, Vol. 12, Issue 5
  • DOI: 10.1063/1.1873792
    [ × clear filter / sort ]

    Similar Records in DOE PAGES and OSTI.GOV collections: