Observation of magnetohydrodynamic instabilities in heliotron J. plasmas

S. Yamamoto; K. Nagasaki; Y. Suzuki; T. Mizuuchi; H. Okada; S. Kobayashi; B. Blackwell; K. Kondo; G. Motojima; N. Nakajima; Y. Nakamura; C. Nührenberg; Y. Torii; S. Watanabe; F. Sano

doi:10.13182/FST07-A1290

Observation of magnetohydrodynamic instabilities in heliotron J. plasmas

S. Yamamoto^*, K. Nagasaki, Y. Suzuki, T. Mizuuchi, H. Okada, S. Kobayashi, B. Blackwell, K. Kondo, G. Motojima, N. Nakajima, Y. Nakamura, C. Nührenberg, Y. Torii, S. Watanabe, F. Sano

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

18 Citations (Scopus)

Abstract

Two kinds of magnetohydrodynamics instability are observed in electron cyclotron heating and neutral beam injection-heated Heliotron J plasmas. One is the pressure-driven interchange modes with m = 2/n = 1 and m = 5/n = 3 and low frequency (f_exp < 20 kHz), which are observed in the plasma with a rational surface of 1/2π= 0.5 or 0.65. The other is the energetic ion-driven global Alfvén eigenmodes (GAEs) in the Alfvén frequency range. To identify the observed GAEs, the frequency of the observed mode with shear Alfvén spectra calculated by CAS3D3 is compared. The interchange mode with m= 5M = 3 and bursting GAE with intense magnetic fluctuations may affect the bulk plasma confinement and energetic ion transport, respectively.

Original language	English
Pages (from-to)	92-96
Number of pages	5
Journal	Fusion Science and Technology
Volume	51
Issue number	1
DOIs	https://doi.org/10.13182/FST07-A1290
Publication status	Published - Jan 2007

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title = "Observation of magnetohydrodynamic instabilities in heliotron J. plasmas",

abstract = "Two kinds of magnetohydrodynamics instability are observed in electron cyclotron heating and neutral beam injection-heated Heliotron J plasmas. One is the pressure-driven interchange modes with m = 2/n = 1 and m = 5/n = 3 and low frequency (fexp < 20 kHz), which are observed in the plasma with a rational surface of 1/2π= 0.5 or 0.65. The other is the energetic ion-driven global Alfv{\'e}n eigenmodes (GAEs) in the Alfv{\'e}n frequency range. To identify the observed GAEs, the frequency of the observed mode with shear Alfv{\'e}n spectra calculated by CAS3D3 is compared. The interchange mode with m= 5M = 3 and bursting GAE with intense magnetic fluctuations may affect the bulk plasma confinement and energetic ion transport, respectively.",

keywords = "Advanced stellarator, Alfv{\'e}n eigenmodes, MHD instabilities",

author = "S. Yamamoto and K. Nagasaki and Y. Suzuki and T. Mizuuchi and H. Okada and S. Kobayashi and B. Blackwell and K. Kondo and G. Motojima and N. Nakajima and Y. Nakamura and C. N{\"u}hrenberg and Y. Torii and S. Watanabe and F. Sano",

year = "2007",

month = jan,

doi = "10.13182/FST07-A1290",

language = "English",

volume = "51",

pages = "92--96",

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TY - JOUR

T1 - Observation of magnetohydrodynamic instabilities in heliotron J. plasmas

AU - Yamamoto, S.

AU - Nagasaki, K.

AU - Suzuki, Y.

AU - Mizuuchi, T.

AU - Okada, H.

AU - Kobayashi, S.

AU - Blackwell, B.

AU - Kondo, K.

AU - Motojima, G.

AU - Nakajima, N.

AU - Nakamura, Y.

AU - Nührenberg, C.

AU - Torii, Y.

AU - Watanabe, S.

AU - Sano, F.

PY - 2007/1

Y1 - 2007/1

N2 - Two kinds of magnetohydrodynamics instability are observed in electron cyclotron heating and neutral beam injection-heated Heliotron J plasmas. One is the pressure-driven interchange modes with m = 2/n = 1 and m = 5/n = 3 and low frequency (fexp < 20 kHz), which are observed in the plasma with a rational surface of 1/2π= 0.5 or 0.65. The other is the energetic ion-driven global Alfvén eigenmodes (GAEs) in the Alfvén frequency range. To identify the observed GAEs, the frequency of the observed mode with shear Alfvén spectra calculated by CAS3D3 is compared. The interchange mode with m= 5M = 3 and bursting GAE with intense magnetic fluctuations may affect the bulk plasma confinement and energetic ion transport, respectively.

AB - Two kinds of magnetohydrodynamics instability are observed in electron cyclotron heating and neutral beam injection-heated Heliotron J plasmas. One is the pressure-driven interchange modes with m = 2/n = 1 and m = 5/n = 3 and low frequency (fexp < 20 kHz), which are observed in the plasma with a rational surface of 1/2π= 0.5 or 0.65. The other is the energetic ion-driven global Alfvén eigenmodes (GAEs) in the Alfvén frequency range. To identify the observed GAEs, the frequency of the observed mode with shear Alfvén spectra calculated by CAS3D3 is compared. The interchange mode with m= 5M = 3 and bursting GAE with intense magnetic fluctuations may affect the bulk plasma confinement and energetic ion transport, respectively.

KW - Advanced stellarator

KW - Alfvén eigenmodes

KW - MHD instabilities

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U2 - 10.13182/FST07-A1290

DO - 10.13182/FST07-A1290

M3 - Article

SN - 1536-1055

VL - 51

SP - 92

EP - 96

JO - Fusion Science and Technology

JF - Fusion Science and Technology

IS - 1

ER -

Observation of magnetohydrodynamic instabilities in heliotron J. plasmas

Abstract

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