Alfven eigenmodes measured in the TJ-II stellarator

被引：48

作者：

Jimenez-Gomez, R. ^{[1
]}

Koenies, A. ^{[2
]}

Ascasibar, E. ^{[1
]}

Castejon, F. ^{[1
]}

Estrada, T. ^{[1
]}

Eliseev, L. G. ^{[3
]}

Melnikov, A. V. ^{[3
]}

Jimenez, J. A. ^{[1
]}

Pretty, D. G. ^{[4
]}

Jimenez-Rey, D. ^{[1
]}

Pedrosa, M. A. ^{[1
]}

de Bustos, A. ^{[1
]}

Yamamoto, S. ^{[5
]}

机构：

[1] Asociaci Euratom CIEMAT, Lab Nacl Fus, Madrid, Spain

[2] IPP Euratom Assoc, Max Planck Inst Plasmaphys, Greifswald, Germany

[3] NRC Kurchatov Inst, Inst Tokamak Phys, Moscow 123182, Russia

[4] Australian Natl Univ, Plasma Res Lab, Canberra, ACT, Australia

[5] Kyoto Univ, Inst Adv Energy, Kyoto 6068501, Japan

来源：

NUCLEAR FUSION | 2011年 / 51卷 / 03期

关键词：

GLOBAL MODES; DRIVEN; INSTABILITIES; TRANSPORT; SPECTRA; PLASMAS;

D O I：

10.1088/0029-5515/51/3/033001

中图分类号：

O35 [流体力学]; O53 [等离子体物理学];

学科分类号：

070204 ; 080103 ; 080704 ;

摘要：

High frequency modes (150-300 kHz) are found in several magnetic configurations of TJ-II plasmas heated by neutral beam injection (NBI). The clear dependence of mode frequency on plasma density and mass species suggests them to be Alfven eigenmodes. The appearance of these modes is linked to the presence of low order rational surfaces close to the rotational transform profile. They can exhibit steady or chirping behaviour depending on the plasma profiles. Frequency chirping is observed in NBI plasmas with broad temperature profiles, but rarely observed with relatively peaked profiles. The Alfvenic activity has been characterized in detail with magnetic coils for the standard configuration. Cross analyses with heavy ion beam probe and reflectometer signals have yielded spatial resolution and radial profiles of the perturbation. Correlation between magnetic coil signals and signals from diagnostics sensitive to edge ion losses, namely Langmuir probes and a fast ion loss detector, has been observed in some cases and characterized taking advantage of the chirping nature of the observed Alfvenic activity.

引用

页数：15

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