Plasma and Fusion Research

Volume 3, S1006 (2008)

Regular Articles

Transport Dynamics and Multi-Scale Coupling of Turbulence in LHD

Shigeru INAGAKI, Naoki TAMURA¹⁾, Yoshihiko NAGASHIMA, Tokihiko TOKUZAWA¹⁾, Takuma YAMADA, Katsumi IDA¹⁾, Takashi MARUTA²⁾, Shin KUBO¹⁾, Kenichi TERASAKA²⁾, Takashi SHIMOZUMA¹⁾, Yoshio NAGAYAMA¹⁾, Kazuo KAWAHATA¹⁾, Akio KOMORI¹⁾, Shunjiro SHINOHARA²⁾, Akihide FUJISAWA¹⁾, Masatoshi YAGI, Yoshinobu KAWAI, Sanae-I. ITOH, Kimitaka ITOH¹⁾ and the LHD experimental group

RIAM, Kyushu University, 6-1 Kasuga-Koen, Kasuga 816-8580, Japan
1): National Institute for Fusion Science,322-6 Oroshi-cho, Toki 509-5292, Japan
2): IGSES, Kyushu University, 6-1 Kasuga-Koen, Kasuga 816-8580, Japan

(Received 16 November 2007 / Accepted 27 March 2008 / Published 5 August 2008)

Abstract

Spatiotemporal correlation of heat transport and micro- to meso- scale or macro-scale coupling of plasma turbulence are investigated in LHD plasmas, where fast propagation of a cold pulse and a non-local temperature rise are observed. Evidence of a timescale shorter than the diffusion time and a spatial scale longer than the micro-turbulence correlation length between core heat fluxes and edge temperature gradients is found. At the same time, an envelope of turbulent density fluctuations is also found to be modulated. Observation of low frequency (≤ 2 kHz) amplitude modulation of density fluctuation suggests the existence of meso- to macro-scale turbulent structures in the plasma, in which a non-local temperature rise takes place. Relationships between the turbulence with long radial correlation length and the edge-core coupling of heat transport are discussed.

Keywords

non-local transport, fluctuation, reflectometry, LHD

DOI: 10.1585/pfr.3.S1006

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This paper may be cited as follows:

Shigeru INAGAKI, Naoki TAMURA, Yoshihiko NAGASHIMA, Tokihiko TOKUZAWA, Takuma YAMADA, Katsumi IDA, Takashi MARUTA, Shin KUBO, Kenichi TERASAKA, Takashi SHIMOZUMA, Yoshio NAGAYAMA, Kazuo KAWAHATA, Akio KOMORI, Shunjiro SHINOHARA, Akihide FUJISAWA, Masatoshi YAGI, Yoshinobu KAWAI, Sanae-I. ITOH, Kimitaka ITOH and the LHD experimental group, Plasma Fusion Res. 3, S1006 (2008).