Observation of Long-Distance Radial Correlation in Toroidal Plasma Turbulence

Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580, Japan.
Physical Review Letters (Impact Factor: 7.51). 09/2011; 107(11):115001. DOI: 10.1103/PHYSREVLETT.107.115001
Source: PubMed


This Letter presents the discovery of macroscale electron temperature fluctuations with a long radial correlation length comparable to the plasma minor radius in a toroidal plasma. Their spatiotemporal structure is characterized by a low frequency of ∼1-3  kHz, ballistic radial propagation, a poloidal or toroidal mode number of m/n=1/1 (or 2/1), and an amplitude of ∼2% at maximum. Nonlinear coupling between the long-range fluctuations and the microscopic fluctuations is identified. A change of the amplitude of the long-range fluctuation is transmitted across the plasma radius at the velocity which is of the order of the drift velocity.

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