Abstract
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.
Original language | English |
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Article number | 075004 |
Journal | Physical Review Letters |
Volume | 103 |
Issue number | 7 |
DOIs | |
State | Published - Aug 14 2009 |
Externally published | Yes |