Electrostatic turbulence driven by high magnetohydrodynamic activity in Tokamak Chauffage Alfvén Brésilien

Guimarães-Filho, Zwinglio O.; Caldas, Iberê L.; Viana, Ricardo L.; Heller, Maria Vittoria A. P.; Nascimento, Ivan C.; Kuznetsov, Yuri K.; Bengtson, Roger D.
June 2008
Physics of Plasmas;Jun2008, Vol. 15 Issue 6, p062501
Academic Journal
In Tokamak Chauffage Alfvén Brésilien [R. M. O. Galvão et al., Plasma Phys. Controlled Fusion 43, 1181 (2001)], high magnetohydrodynamic (MHD) activity may appear spontaneously or during discharges with a voltage biased electrode inserted at the plasma edge. The turbulent electrostatic fluctuations, measured by Langmuir probes, are modulated by Mirnov oscillations presenting a dominant peak with a common frequency around 10 kHz. We report the occurrence of phase locking of the turbulent potential fluctuations driven by MHD activity at this frequency. Using wavelet cross-spectral analysis, we characterized the phase and frequency synchronization in the plasma edge region. We introduced an order parameter to characterize the radial dependence of the phase-locking intensity.


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