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Title: Magnetic Polarization Measurements of the Multi-modal Plasma Response to 3D fields in the EAST Tokamak

Abstract

A multi-modal plasma response to applied non-axisymmetric fields has been found in EAST tokamak plasmas. Here, multi-modal means the radial and poloidal structure of an individually driven toroidal harmonic is not fixed. The signature of such a multi-modal response is the magnetic polarization (ratio of radial and poloidal components) of the plasma response field measured on the low field side device mid-plane. A difference in the 3D coil phasing (the relative phase of two coil arrays) dependencies between the two responses is observed in response to n=2 fields in the same plasma for which the n=1 responses are well synchronized. Neither the maximum radial nor the maximum poloidal field response to n=2 fields agrees with the best applied phasing for mitigating edge localized modes, suggesting that the edge plasma response is not a dominant component of either polarization. GPEC modeling reproduces the discrepant phasing dependences of the experimental measurements, and confirms the edge resonances are maximized by the coil phasing that mitigates ELMs in the experiments. The model confirms the measured plasma response is not dominated by resonant current drive from the external field. Instead, non-resonant contributions play a large role in the diagnostic signal for both toroidal harmonics n=1more » and n=2. The analysis in this paper demonstrates the ability of 3D modeling to connect external magnetic sensor measurements to the internal plasma physics and accurately predict optimal applied 3D field configurations in multi-modal plasmas.« less

Authors:
 [1];  [1];  [2]; ORCiD logo [2];  [2]; ORCiD logo [2];  [1];  [3]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. Chinese Academy of Sciences, Anhui (China)
  3. General Atomics, San Diego, CA (United States)
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1436768
Grant/Contract Number:  
AC02-09CH11466; 11475224
Resource Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 58; Journal Issue: 7; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Tokamak; Resonant Magnetic Perturbations; Edge Localized Modes; Reluctance; GPEC

Citation Formats

Logan, Nikolas, Cui, L., Wang, Hui -Hui, Sun, Youwen, Gu, Shuai, Li, Guoqiang, Nazikian, Raffi, and Paz-Soldan, Carlos. Magnetic Polarization Measurements of the Multi-modal Plasma Response to 3D fields in the EAST Tokamak. United States: N. p., 2018. Web. https://doi.org/10.1088/1741-4326/aac129.
Logan, Nikolas, Cui, L., Wang, Hui -Hui, Sun, Youwen, Gu, Shuai, Li, Guoqiang, Nazikian, Raffi, & Paz-Soldan, Carlos. Magnetic Polarization Measurements of the Multi-modal Plasma Response to 3D fields in the EAST Tokamak. United States. https://doi.org/10.1088/1741-4326/aac129
Logan, Nikolas, Cui, L., Wang, Hui -Hui, Sun, Youwen, Gu, Shuai, Li, Guoqiang, Nazikian, Raffi, and Paz-Soldan, Carlos. Mon . "Magnetic Polarization Measurements of the Multi-modal Plasma Response to 3D fields in the EAST Tokamak". United States. https://doi.org/10.1088/1741-4326/aac129. https://www.osti.gov/servlets/purl/1436768.
@article{osti_1436768,
title = {Magnetic Polarization Measurements of the Multi-modal Plasma Response to 3D fields in the EAST Tokamak},
author = {Logan, Nikolas and Cui, L. and Wang, Hui -Hui and Sun, Youwen and Gu, Shuai and Li, Guoqiang and Nazikian, Raffi and Paz-Soldan, Carlos},
abstractNote = {A multi-modal plasma response to applied non-axisymmetric fields has been found in EAST tokamak plasmas. Here, multi-modal means the radial and poloidal structure of an individually driven toroidal harmonic is not fixed. The signature of such a multi-modal response is the magnetic polarization (ratio of radial and poloidal components) of the plasma response field measured on the low field side device mid-plane. A difference in the 3D coil phasing (the relative phase of two coil arrays) dependencies between the two responses is observed in response to n=2 fields in the same plasma for which the n=1 responses are well synchronized. Neither the maximum radial nor the maximum poloidal field response to n=2 fields agrees with the best applied phasing for mitigating edge localized modes, suggesting that the edge plasma response is not a dominant component of either polarization. GPEC modeling reproduces the discrepant phasing dependences of the experimental measurements, and confirms the edge resonances are maximized by the coil phasing that mitigates ELMs in the experiments. The model confirms the measured plasma response is not dominated by resonant current drive from the external field. Instead, non-resonant contributions play a large role in the diagnostic signal for both toroidal harmonics n=1 and n=2. The analysis in this paper demonstrates the ability of 3D modeling to connect external magnetic sensor measurements to the internal plasma physics and accurately predict optimal applied 3D field configurations in multi-modal plasmas.},
doi = {10.1088/1741-4326/aac129},
journal = {Nuclear Fusion},
number = 7,
volume = 58,
place = {United States},
year = {2018},
month = {4}
}

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Works referenced in this record:

Computation of three-dimensional tokamak and spherical torus equilibria
journal, May 2007

  • Park, Jong-kyu; Boozer, Allen H.; Glasser, Alan H.
  • Physics of Plasmas, Vol. 14, Issue 5
  • DOI: 10.1063/1.2732170

Nonlinear Transition from Mitigation to Suppression of the Edge Localized Mode with Resonant Magnetic Perturbations in the EAST Tokamak
journal, September 2016


Experimental tests of linear and nonlinear three-dimensional equilibrium models in DIII-D
journal, July 2015

  • King, J. D.; Strait, E. J.; Lazerson, S. A.
  • Physics of Plasmas, Vol. 22, Issue 7
  • DOI: 10.1063/1.4923017

Reconstruction of current profile parameters and plasma shapes in tokamaks
journal, November 1985


Equilibrium analysis of current profiles in tokamaks
journal, June 1990


Development of the ITER magnetic diagnostic set and specification
journal, October 2012

  • Vayakis, G.; Arshad, S.; Delhom, D.
  • Review of Scientific Instruments, Vol. 83, Issue 10
  • DOI: 10.1063/1.4732077

Neoclassical flows and transport in nonaxisymmetric toroidal plasmas
journal, January 1983


Error Field Amplification and Rotation Damping in Tokamak Plasmas
journal, May 2001


Self-consistent perturbed equilibrium with neoclassical toroidal torque in tokamaks
journal, March 2017

  • Park, Jong-Kyu; Logan, Nikolas C.
  • Physics of Plasmas, Vol. 24, Issue 3
  • DOI: 10.1063/1.4977898

Resonant magnetic perturbations of edge-plasmas in toroidal confinement devices
journal, November 2015


Sustained suppression of type-I edge-localized modes with dominantly n = 2 magnetic fields in DIII-D
journal, July 2013


Numerical optimization of three-dimensional coils for NSTX-U
journal, September 2015


Control of Nonaxisymmetric Magnetic Field Perturbations in Tokamaks
journal, April 2011


The ITER 3D magnetic diagnostic response to applied n = 3 and n = 4 resonant magnetic perturbations
journal, July 2014


Non-axisymmetric magnetic fields and toroidal plasma confinement
journal, January 2015


Calculations of two-fluid linear response to non-axisymmetric fields in tokamaks
journal, May 2012


Equilibrium Reconstruction in EAST Tokamak
journal, April 2009


Spatial and temporal analysis of DIII-D 3D magnetic diagnostic data
journal, August 2016

  • Strait, E. J.; King, J. D.; Hanson, J. M.
  • Review of Scientific Instruments, Vol. 87, Issue 11
  • DOI: 10.1063/1.4960419

Decoupled recovery of energy and momentum with correction of n   =  2 error fields
journal, July 2015


Measurement of the Resistive-Wall-Mode Stability in a Rotating Plasma Using Active MHD Spectroscopy
journal, September 2004


Computation of resistive instabilities by matched asymptotic expansions
journal, November 2016

  • Glasser, A. H.; Wang, Z. R.; Park, J. -K.
  • Physics of Plasmas, Vol. 23, Issue 11
  • DOI: 10.1063/1.4967862

The spectral basis of optimal error field correction on DIII-D
journal, April 2014


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

Advances in the physics understanding of ELM suppression using resonant magnetic perturbations in DIII-D
journal, January 2015


The importance of matched poloidal spectra to error field correction in DIII-D
journal, July 2014

  • Paz-Soldan, C.; Lanctot, M. J.; Logan, N. C.
  • Physics of Plasmas, Vol. 21, Issue 7
  • DOI: 10.1063/1.4886795

Magnetic control of magnetohydrodynamic instabilities in tokamaks
journal, November 2014


Neoclassical Toroidal Plasma Viscosity Torque in Collisionless Regimes in Tokamaks
journal, October 2010


ELM mitigation techniques
journal, July 2013


Resistive wall modes and error field amplification
journal, May 2003


Identification of multi-modal plasma responses to applied magnetic perturbations using the plasma reluctance
journal, May 2016

  • Logan, Nikolas C.; Paz-Soldan, Carlos; Park, Jong-Kyu
  • Physics of Plasmas, Vol. 23, Issue 5
  • DOI: 10.1063/1.4948281

The direct criterion of Newcomb for the ideal MHD stability of an axisymmetric toroidal plasma
journal, July 2016


Advances in global MHD mode stabilization research on NSTX
journal, January 2010


Reactor-relevant quiescent H-mode operation using torque from non-axisymmetric, non-resonant magnetic fields
journal, May 2012

  • Burrell, K. H.; Garofalo, A. M.; Solomon, W. M.
  • Physics of Plasmas, Vol. 19, Issue 5
  • DOI: 10.1063/1.3695119

Neoclassical toroidal viscosity in perturbed equilibria with general tokamak geometry
journal, December 2013

  • Logan, Nikolas C.; Park, Jong-Kyu; Kim, Kimin
  • Physics of Plasmas, Vol. 20, Issue 12
  • DOI: 10.1063/1.4849395

Observation of Plasma Rotation Driven by Static Nonaxisymmetric Magnetic Fields in a Tokamak
journal, November 2008


Measurement of tokamak error fields using plasma response and its applicability to ITER
journal, April 2014


Neoclassical plasma viscosity and transport processes in non-axisymmetric tori
journal, November 2015


Observation of a Multimode Plasma Response and its Relationship to Density Pumpout and Edge-Localized Mode Suppression
journal, March 2015


Kinetic energy principle and neoclassical toroidal torque in tokamaks
journal, November 2011


Control of Asymmetric Magnetic Perturbations in Tokamaks
journal, November 2007


Pedestal Bifurcation and Resonant Field Penetration at the Threshold of Edge-Localized Mode Suppression in the DIII-D Tokamak
journal, March 2015


Error Field Amplification and Rotation Damping in Tokamak Plasmas
journal, May 2001


Measurement of the Resistive-Wall-Mode Stability in a Rotating Plasma Using Active MHD Spectroscopy
journal, September 2004


Observation of a Multimode Plasma Response and its Relationship to Density Pumpout and Edge-Localized Mode Suppression
journal, March 2015


Observation of Plasma Rotation Driven by Static Nonaxisymmetric Magnetic Fields in a Tokamak
journal, November 2008


Control of Asymmetric Magnetic Perturbations in Tokamaks
journal, November 2007


Pedestal Bifurcation and Resonant Field Penetration at the Threshold of Edge-Localized Mode Suppression in the DIII-D Tokamak
journal, March 2015


Neoclassical Toroidal Plasma Viscosity Torque in Collisionless Regimes in Tokamaks
journal, October 2010


Control of Nonaxisymmetric Magnetic Field Perturbations in Tokamaks
journal, April 2011


Nonlinear Transition from Mitigation to Suppression of the Edge Localized Mode with Resonant Magnetic Perturbations in the EAST Tokamak
journal, September 2016


    Works referencing / citing this record:

    Identification of multiple eigenmode growth rates in DIII-D and EAST tokamak plasmas
    journal, January 2019


    A new criterion for controlling edge localized modes based on a multi-mode plasma response
    journal, October 2019