Localized Turbulence Suppression and Increased Flow Shear near the q=2 Surface during Internal-Transport-Barrier Formation

Journal Article · Fri Aug 14 00:00:00 EDT 2009 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.103.075004· OSTI ID:21370663

Shafer, M W; McKee, G R; Fonck, R J; Schlossberg, D J ^[1]; Austin, M E ^[2]; Burrell, K H ^[3]

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1. University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin, 53706 (United States)
2. University of Texas-Austin, 1 University Station, Austin, Texas 78712 (United States)
3. General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

Broadband turbulent fluctuations in the plasma density are transiently suppressed when low-order rational q surfaces first appear in negative central magnetic shear plasmas on the DIII-D tokamak, which can lead to the formation of internal transport barriers. Increased localized flow shear is simultaneously observed. It transiently exceeds the measured turbulence decorrelation rate, providing a mechanism to trigger the formation of the transport barrier. This increased flow shear and turbulence suppression propagates radially outward, following the q=2 surface.

• OSTI ID: 21370663
• Journal Information: Physical Review Letters, Vol. 103, Issue 7; Other Information: DOI: 10.1103/PhysRevLett.103.075004; (c) 2009 The American Physical Society; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DOUBLET-3 DEVICE
PLASMA
PLASMA DENSITY
SURFACES
TURBULENCE
CLOSED PLASMA DEVICES
THERMONUCLEAR DEVICES
TOKAMAK DEVICES