Experiment and simulation of tearing mode evolution with electron cyclotron current drive in KSTAR

Kyungjin Kim; Yong Su Na; Minhwa Kim; Y. M. Jeon; K. D. Lee; J. G. Bak; M. J. Choi; G. S. Yun; S. G. Lee; S. Park; J. H. Jeong; L. Terzolo; D. H. Na; M. G. Yoo

doi:10.1016/j.cap.2015.01.032

Experiment and simulation of tearing mode evolution with electron cyclotron current drive in KSTAR

Kyungjin Kim, Yong Su Na, Minhwa Kim, Y. M. Jeon, K. D. Lee, J. G. Bak, M. J. Choi, G. S. Yun, S. G. Lee, S. Park, J. H. Jeong, L. Terzolo, D. H. Na, M. G. Yoo

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11 Scopus citations

Abstract

The tearing mode (TM) plasma instability was observed in low confinement (L-mode) plasmas when non-axisymmetric magnetic perturbation (MP) was applied using external coils during 2011 campaign of KSTAR. Based on the collected information of the magnetic island location in a plasma, a discharge was designed for suppression of a (2,1) TM mode by adjusting electron cyclotron (EC) launcher angles to the estimated island position. Here, the (m,n) notation describes the poloidal mode number and the toroidal mode number of the TM, respectively. The discharge is analysed with experimental observations and numerical simulations. Mirnov coil (MC) arrays and electron cyclotron emission (ECE) are used for analysis of the island width and the location as well as the mode number. The EC deposition and its alignment with the island are estimated by X-ray imaging crystal spectroscopy (XICS) and ECE measurements. An integrated numerical system is employed for modelling of this discharge to analyse a temporal evolution of the mode activity by integrating plasma equilibrium, transport, heating and current drive, and the magnetic island evolution, in a self-consistent way. The effect of EC current drive is discussed by comparing with another TM discharge but without ECCD. Some possibilities for classifying this mode to neoclassical tearing mode (NTM) and stabilisation effect of ECCD are suggested based on the experimental observation and the simulation results.

Original language	English
Pages (from-to)	547-554
Number of pages	8
Journal	Current Applied Physics
Volume	15
Issue number	4
DOIs	https://doi.org/10.1016/j.cap.2015.01.032
State	Published - Apr 2015
Externally published	Yes

Funding

This research was supported by National R&D Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (No. 2014M1A7A1A03045368 ). Two of the authors (MJC and GSY) would like to acknowledge support from the NRF Korea under grant NRF-2014M1A7A1A03029865 and NRF-2014M1A7A1A03029881 .

Funders	Funder number
Ministry of Science, ICT and Future Planning	2014M1A7A1A03045368, NRF-2014M1A7A1A03029881, NRF-2014M1A7A1A03029865
National Research Foundation of Korea

Keywords

Electron cyclotron current drive
KSTAR
Neoclassical tearing mode
Plasma instability
Tearing mode
Tokamak

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1016/j.cap.2015.01.032

Cite this

@article{aadd9362b6d04279866ecbb6f35945fe,

title = "Experiment and simulation of tearing mode evolution with electron cyclotron current drive in KSTAR",

abstract = "The tearing mode (TM) plasma instability was observed in low confinement (L-mode) plasmas when non-axisymmetric magnetic perturbation (MP) was applied using external coils during 2011 campaign of KSTAR. Based on the collected information of the magnetic island location in a plasma, a discharge was designed for suppression of a (2,1) TM mode by adjusting electron cyclotron (EC) launcher angles to the estimated island position. Here, the (m,n) notation describes the poloidal mode number and the toroidal mode number of the TM, respectively. The discharge is analysed with experimental observations and numerical simulations. Mirnov coil (MC) arrays and electron cyclotron emission (ECE) are used for analysis of the island width and the location as well as the mode number. The EC deposition and its alignment with the island are estimated by X-ray imaging crystal spectroscopy (XICS) and ECE measurements. An integrated numerical system is employed for modelling of this discharge to analyse a temporal evolution of the mode activity by integrating plasma equilibrium, transport, heating and current drive, and the magnetic island evolution, in a self-consistent way. The effect of EC current drive is discussed by comparing with another TM discharge but without ECCD. Some possibilities for classifying this mode to neoclassical tearing mode (NTM) and stabilisation effect of ECCD are suggested based on the experimental observation and the simulation results.",

keywords = "Electron cyclotron current drive, KSTAR, Neoclassical tearing mode, Plasma instability, Tearing mode, Tokamak",

author = "Kyungjin Kim and Na, {Yong Su} and Minhwa Kim and Jeon, {Y. M.} and Lee, {K. D.} and Bak, {J. G.} and Choi, {M. J.} and Yun, {G. S.} and Lee, {S. G.} and S. Park and Jeong, {J. H.} and L. Terzolo and Na, {D. H.} and Yoo, {M. G.}",

note = "Publisher Copyright: {\textcopyright} 2015 Elsevier B.V.",

year = "2015",

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doi = "10.1016/j.cap.2015.01.032",

language = "English",

volume = "15",

pages = "547--554",

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T1 - Experiment and simulation of tearing mode evolution with electron cyclotron current drive in KSTAR

AU - Kim, Kyungjin

AU - Na, Yong Su

AU - Kim, Minhwa

AU - Jeon, Y. M.

AU - Lee, K. D.

AU - Bak, J. G.

AU - Choi, M. J.

AU - Yun, G. S.

AU - Lee, S. G.

AU - Park, S.

AU - Jeong, J. H.

AU - Terzolo, L.

AU - Na, D. H.

AU - Yoo, M. G.

PY - 2015/4

Y1 - 2015/4

N2 - The tearing mode (TM) plasma instability was observed in low confinement (L-mode) plasmas when non-axisymmetric magnetic perturbation (MP) was applied using external coils during 2011 campaign of KSTAR. Based on the collected information of the magnetic island location in a plasma, a discharge was designed for suppression of a (2,1) TM mode by adjusting electron cyclotron (EC) launcher angles to the estimated island position. Here, the (m,n) notation describes the poloidal mode number and the toroidal mode number of the TM, respectively. The discharge is analysed with experimental observations and numerical simulations. Mirnov coil (MC) arrays and electron cyclotron emission (ECE) are used for analysis of the island width and the location as well as the mode number. The EC deposition and its alignment with the island are estimated by X-ray imaging crystal spectroscopy (XICS) and ECE measurements. An integrated numerical system is employed for modelling of this discharge to analyse a temporal evolution of the mode activity by integrating plasma equilibrium, transport, heating and current drive, and the magnetic island evolution, in a self-consistent way. The effect of EC current drive is discussed by comparing with another TM discharge but without ECCD. Some possibilities for classifying this mode to neoclassical tearing mode (NTM) and stabilisation effect of ECCD are suggested based on the experimental observation and the simulation results.

AB - The tearing mode (TM) plasma instability was observed in low confinement (L-mode) plasmas when non-axisymmetric magnetic perturbation (MP) was applied using external coils during 2011 campaign of KSTAR. Based on the collected information of the magnetic island location in a plasma, a discharge was designed for suppression of a (2,1) TM mode by adjusting electron cyclotron (EC) launcher angles to the estimated island position. Here, the (m,n) notation describes the poloidal mode number and the toroidal mode number of the TM, respectively. The discharge is analysed with experimental observations and numerical simulations. Mirnov coil (MC) arrays and electron cyclotron emission (ECE) are used for analysis of the island width and the location as well as the mode number. The EC deposition and its alignment with the island are estimated by X-ray imaging crystal spectroscopy (XICS) and ECE measurements. An integrated numerical system is employed for modelling of this discharge to analyse a temporal evolution of the mode activity by integrating plasma equilibrium, transport, heating and current drive, and the magnetic island evolution, in a self-consistent way. The effect of EC current drive is discussed by comparing with another TM discharge but without ECCD. Some possibilities for classifying this mode to neoclassical tearing mode (NTM) and stabilisation effect of ECCD are suggested based on the experimental observation and the simulation results.

KW - Electron cyclotron current drive

KW - KSTAR

KW - Neoclassical tearing mode

KW - Plasma instability

KW - Tearing mode

KW - Tokamak

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DO - 10.1016/j.cap.2015.01.032

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SN - 1567-1739

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EP - 554

JO - Current Applied Physics

JF - Current Applied Physics

IS - 4

ER -

Experiment and simulation of tearing mode evolution with electron cyclotron current drive in KSTAR

Abstract

Funding

Keywords

UN SDGs

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