Effect of n = 3 perturbation field amplitudes below the ELM triggering threshold on edge and SOL transport in NSTX

Lore, J. D.; Ahn, J. -W.; Bortolon, A.; Fredrickson, E. D.; Jaworski, M. A.; Kramer, G. J.; Maingi, R.; McLean, A. G.; Scotti, F.; Soukhanovskii, V. A.; Tritz, K.

doi:10.1016/j.jnucmat.2013.01.077

Title: Effect of n = 3 perturbation field amplitudes below the ELM triggering threshold on edge and SOL transport in NSTX

Abstract

Here, the pulsed application of n = 3 magnetic perturbation fields with amplitudes below that which triggers ELMs results in distinct, transient responses observable on several edge and divertor diagnostics in NSTX. We refer to these responses as Sub-Threshold Edge Perturbations (STEPs). An analysis of edge measurements suggests that STEPs result in increased transport in the plasma edge and scrape-off layer, which leads to augmentation of the intrinsic strike point splitting due to error fields, i.e., an intensification of the helical divertor footprint flux pattern. These effects are much smaller in magnitude than those of triggered ELMs, and are observed for the duration of the field perturbation measured internal to the vacuum vessel. In addition, STEPs are correlated with changes to the MHD activity, along with transient reductions in the neutron production rate. Ideally the STEPs could be used to provide density control and prevent impurity accumulation, in the same manner that on-demand ELM triggering is used on NSTX, without the impulsive divertor fluxes and potential for damage to plasma facing components associated with ELMs.

Authors:

J. M. Canik; Lore, J. D. ^[1]; Ahn, J. -W. ^[1]; Bortolon, A. ^[2]; Fredrickson, E. D. ^[3]; Jaworski, M. A. ^[3]; Kramer, G. J. ^[3]; Maingi, R. ^[1]; McLean, A. G. ^[4]; Scotti, F. ^[3]; Soukhanovskii, V. A. ^[4]; Tritz, K. ^[5]

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Univ. of California, Irvine, CA (United States)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
John Hopkins Univ., Baltimore, MD (United States)

Publication Date:: Sat Jan 12 00:00:00 EST 2013

Research Org.:: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1266678

Report Number(s):: LLNL-JRNL-560792
Journal ID: ISSN 0022-3115

Grant/Contract Number:: AC52-07NA27344

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Nuclear Materials

Additional Journal Information:: Journal Volume: 438; Journal Issue: S; Journal ID: ISSN 0022-3115

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION

Citation Formats


                    J. M. Canik, Lore, J. D., Ahn, J. -W., Bortolon, A., Fredrickson, E. D., Jaworski, M. A., Kramer, G. J., Maingi, R., McLean, A. G., Scotti, F., Soukhanovskii, V. A., and Tritz, K. Effect of n = 3 perturbation field amplitudes below the ELM triggering threshold on edge and SOL transport in NSTX.  United States: N. p., 2013. 
Web.  doi:10.1016/j.jnucmat.2013.01.077.

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                    J. M. Canik, Lore, J. D., Ahn, J. -W., Bortolon, A., Fredrickson, E. D., Jaworski, M. A., Kramer, G. J., Maingi, R., McLean, A. G., Scotti, F., Soukhanovskii, V. A., & Tritz, K. Effect of n = 3 perturbation field amplitudes below the ELM triggering threshold on edge and SOL transport in NSTX.  United States.  https://doi.org/10.1016/j.jnucmat.2013.01.077

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                    J. M. Canik, Lore, J. D., Ahn, J. -W., Bortolon, A., Fredrickson, E. D., Jaworski, M. A., Kramer, G. J., Maingi, R., McLean, A. G., Scotti, F., Soukhanovskii, V. A., and Tritz, K. Sat .  
"Effect of n = 3 perturbation field amplitudes below the ELM triggering threshold on edge and SOL transport in NSTX".  United States.  https://doi.org/10.1016/j.jnucmat.2013.01.077.  https://www.osti.gov/servlets/purl/1266678.

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@article{osti_1266678,

  title        = {Effect of n = 3 perturbation field amplitudes below the ELM triggering threshold on edge and SOL transport in NSTX},

  author       = {J. M. Canik and Lore, J. D. and Ahn, J. -W. and Bortolon, A. and Fredrickson, E. D. and Jaworski, M. A. and Kramer, G. J. and Maingi, R. and McLean, A. G. and Scotti, F. and Soukhanovskii, V. A. and Tritz, K.},

  abstractNote = {Here, the pulsed application of n = 3 magnetic perturbation fields with amplitudes below that which triggers ELMs results in distinct, transient responses observable on several edge and divertor diagnostics in NSTX. We refer to these responses as Sub-Threshold Edge Perturbations (STEPs). An analysis of edge measurements suggests that STEPs result in increased transport in the plasma edge and scrape-off layer, which leads to augmentation of the intrinsic strike point splitting due to error fields, i.e., an intensification of the helical divertor footprint flux pattern. These effects are much smaller in magnitude than those of triggered ELMs, and are observed for the duration of the field perturbation measured internal to the vacuum vessel. In addition, STEPs are correlated with changes to the MHD activity, along with transient reductions in the neutron production rate. Ideally the STEPs could be used to provide density control and prevent impurity accumulation, in the same manner that on-demand ELM triggering is used on NSTX, without the impulsive divertor fluxes and potential for damage to plasma facing components associated with ELMs.},

  doi          = {10.1016/j.jnucmat.2013.01.077},

  journal      = {Journal of Nuclear Materials},

  number       = S,

  volume       = 438,

  place        = {United States},

  year         = {Sat Jan 12 00:00:00 EST 2013},

  month        = {Sat Jan 12 00:00:00 EST 2013}

}

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Works referenced in this record:

Effects of ergodization on plasma confinement in JFT-2M
journal, December 1992

Shoji, T.; Tamai, H.; Miura, Y.
Journal of Nuclear Materials, Vol. 196-198
DOI: 10.1016/S0022-3115(06)80049-8

Suppression of Large Edge-Localized Modes in High-Confinement DIII-D Plasmas with a Stochastic Magnetic Boundary
journal, June 2004

Evans, T. E.; Moyer, R. A.; Thomas, P. R.
Physical Review Letters, Vol. 92, Issue 23
DOI: 10.1103/PhysRevLett.92.235003

Scaling of Electron and Ion Transport in the High-Power Spherical Torus NSTX
journal, April 2007

Kaye, S. M.; Bell, R. E.; Gates, D.
Physical Review Letters, Vol. 98, Issue 17
DOI: 10.1103/PhysRevLett.98.175002

Active Control of Type-I Edge-Localized Modes with $n = 1$ Perturbation Fields in the JET Tokamak
journal, June 2007

Liang, Y.; Koslowski, H. R.; Thomas, P. R.
Physical Review Letters, Vol. 98, Issue 26
DOI: 10.1103/PhysRevLett.98.265004

First Observation of Edge Localized Modes Mitigation with Resonant and Nonresonant Magnetic Perturbations in ASDEX Upgrade
journal, June 2011

Suttrop, W.; Eich, T.; Fuchs, J. C.
Physical Review Letters, Vol. 106, Issue 22
DOI: 10.1103/PhysRevLett.106.225004

ELM control experiments in the KSTAR device
journal, October 2012

Kim, Jayhyun; Jeon, Y. -M.; Xiao, W. W.
Nuclear Fusion, Vol. 52, Issue 11
DOI: 10.1088/0029-5515/52/11/114011

On Demand Triggering of Edge Localized Instabilities Using External Nonaxisymmetric Magnetic Perturbations in Toroidal Plasmas
journal, January 2010

Canik, J. M.; Maingi, R.; Evans, T. E.
Physical Review Letters, Vol. 104, Issue 4
DOI: 10.1103/PhysRevLett.104.045001

Progress in the development of ELM pace-making with non-axisymmetric magnetic perturbations in NSTX
journal, May 2010

Canik, J. M.; Sontag, A. C.; Maingi, R.
Nuclear Fusion, Vol. 50, Issue 6
DOI: 10.1088/0029-5515/50/6/064016

Modification of divertor heat and particle flux profiles with applied 3D fields in NSTX H-mode plasmas
journal, April 2010

Ahn, J. -W.; Canik, J. M.; Soukhanovskii, V. A.
Nuclear Fusion, Vol. 50, Issue 4
DOI: 10.1088/0029-5515/50/4/045010

Effect of nonaxisymmetric magnetic perturbations on divertor heat and particle flux profiles in National Spherical Torus Experiment
journal, May 2011

Ahn, J-W.; Maingi, R.; Canik, J. M.
Physics of Plasmas, Vol. 18, Issue 5
DOI: 10.1063/1.3574522

ELM destabilization by externally applied non-axisymmetric magnetic perturbations in NSTX
journal, February 2010

Canik, J. M.; Maingi, R.; Evans, T. E.
Nuclear Fusion, Vol. 50, Issue 3
DOI: 10.1088/0029-5515/50/3/034012

Active Stabilization of the Resistive-Wall Mode in High-Beta, Low-Rotation Plasmas
journal, July 2006

Sabbagh, S. A.; Bell, R. E.; Menard, J. E.
Physical Review Letters, Vol. 97, Issue 4
DOI: 10.1103/PhysRevLett.97.045004

Triggered Confinement Enhancement and Pedestal Expansion in High-Confinement-Mode Discharges in the National Spherical Torus Experiment
journal, September 2010

Maingi, R.; Bell, R. E.; Canik, J. M.
Physical Review Letters, Vol. 105, Issue 13
DOI: 10.1103/PhysRevLett.105.135004

Overview of the results on divertor heat loads in RMP controlled H-mode plasmas on DIII-D
journal, August 2009

Jakubowski, M. W.; Evans, T. E.; Fenstermacher, M. E.
Nuclear Fusion, Vol. 49, Issue 9
DOI: 10.1088/0029-5515/49/9/095013

Strike-point splitting induced by external magnetic perturbations: Observations on JET and MAST and associated modelling
journal, August 2011

Nardon, E.; Cahyna, P.; Devaux, S.
Journal of Nuclear Materials, Vol. 415, Issue 1
DOI: 10.1016/j.jnucmat.2010.10.072

Strike point splitting in the heat and particle flux profiles compared with the edge magnetic topology in a n = 2 resonant magnetic perturbation field at JET
journal, May 2012

Harting, D. M.; Liang, Y.; Jachmich, S.
Nuclear Fusion, Vol. 52, Issue 5
DOI: 10.1088/0029-5515/52/5/054009

Full toroidal imaging of non-axisymmetric plasma material interaction in the National Spherical Torus Experiment divertor
journal, October 2012

Scotti, Filippo; Roquemore, A. L.; Soukhanovskii, V. A.
Review of Scientific Instruments, Vol. 83, Issue 10
DOI: 10.1063/1.4739510

Edge turbulence measurements in toroidal fusion devices
journal, June 2007

Zweben, S. J.; Boedo, J. A.; Grulke, O.
Plasma Physics and Controlled Fusion, Vol. 49, Issue 7
DOI: 10.1088/0741-3335/49/7/S01

Collective fast ion instability-induced losses in National Spherical Tokamak Experiment
journal, May 2006

Fredrickson, E. D.; Bell, R. E.; Darrow, D. S.
Physics of Plasmas, Vol. 13, Issue 5
DOI: 10.1063/1.2178788

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Title: Effect of n = 3 perturbation field amplitudes below the ELM triggering threshold on edge and SOL transport in NSTX

Abstract

Citation Formats

Effects of ergodization on plasma confinement in JFT-2M journal, December 1992

Suppression of Large Edge-Localized Modes in High-Confinement DIII-D Plasmas with a Stochastic Magnetic Boundary journal, June 2004

Scaling of Electron and Ion Transport in the High-Power Spherical Torus NSTX journal, April 2007

Active Control of Type-I Edge-Localized Modes with n = 1 Perturbation Fields in the JET Tokamak journal, June 2007

First Observation of Edge Localized Modes Mitigation with Resonant and Nonresonant Magnetic Perturbations in ASDEX Upgrade journal, June 2011

ELM control experiments in the KSTAR device journal, October 2012

On Demand Triggering of Edge Localized Instabilities Using External Nonaxisymmetric Magnetic Perturbations in Toroidal Plasmas journal, January 2010

Progress in the development of ELM pace-making with non-axisymmetric magnetic perturbations in NSTX journal, May 2010

Modification of divertor heat and particle flux profiles with applied 3D fields in NSTX H-mode plasmas journal, April 2010

Effect of nonaxisymmetric magnetic perturbations on divertor heat and particle flux profiles in National Spherical Torus Experiment journal, May 2011

ELM destabilization by externally applied non-axisymmetric magnetic perturbations in NSTX journal, February 2010

Active Stabilization of the Resistive-Wall Mode in High-Beta, Low-Rotation Plasmas journal, July 2006

Triggered Confinement Enhancement and Pedestal Expansion in High-Confinement-Mode Discharges in the National Spherical Torus Experiment journal, September 2010

Overview of the results on divertor heat loads in RMP controlled H-mode plasmas on DIII-D journal, August 2009

Strike-point splitting induced by external magnetic perturbations: Observations on JET and MAST and associated modelling journal, August 2011

Strike point splitting in the heat and particle flux profiles compared with the edge magnetic topology in a n = 2 resonant magnetic perturbation field at JET journal, May 2012

Full toroidal imaging of non-axisymmetric plasma material interaction in the National Spherical Torus Experiment divertor journal, October 2012

Edge turbulence measurements in toroidal fusion devices journal, June 2007

Collective fast ion instability-induced losses in National Spherical Tokamak Experiment journal, May 2006

Effects of ergodization on plasma confinement in JFT-2M
journal, December 1992

Suppression of Large Edge-Localized Modes in High-Confinement DIII-D Plasmas with a Stochastic Magnetic Boundary
journal, June 2004

Scaling of Electron and Ion Transport in the High-Power Spherical Torus NSTX
journal, April 2007

Active Control of Type-I Edge-Localized Modes with $n = 1$ Perturbation Fields in the JET Tokamak
journal, June 2007

First Observation of Edge Localized Modes Mitigation with Resonant and Nonresonant Magnetic Perturbations in ASDEX Upgrade
journal, June 2011

ELM control experiments in the KSTAR device
journal, October 2012

On Demand Triggering of Edge Localized Instabilities Using External Nonaxisymmetric Magnetic Perturbations in Toroidal Plasmas
journal, January 2010

Progress in the development of ELM pace-making with non-axisymmetric magnetic perturbations in NSTX
journal, May 2010

Modification of divertor heat and particle flux profiles with applied 3D fields in NSTX H-mode plasmas
journal, April 2010

Effect of nonaxisymmetric magnetic perturbations on divertor heat and particle flux profiles in National Spherical Torus Experiment
journal, May 2011

ELM destabilization by externally applied non-axisymmetric magnetic perturbations in NSTX
journal, February 2010

Active Stabilization of the Resistive-Wall Mode in High-Beta, Low-Rotation Plasmas
journal, July 2006

Triggered Confinement Enhancement and Pedestal Expansion in High-Confinement-Mode Discharges in the National Spherical Torus Experiment
journal, September 2010

Overview of the results on divertor heat loads in RMP controlled H-mode plasmas on DIII-D
journal, August 2009

Strike-point splitting induced by external magnetic perturbations: Observations on JET and MAST and associated modelling
journal, August 2011

Strike point splitting in the heat and particle flux profiles compared with the edge magnetic topology in a n = 2 resonant magnetic perturbation field at JET
journal, May 2012

Full toroidal imaging of non-axisymmetric plasma material interaction in the National Spherical Torus Experiment divertor
journal, October 2012

Edge turbulence measurements in toroidal fusion devices
journal, June 2007

Collective fast ion instability-induced losses in National Spherical Tokamak Experiment
journal, May 2006