APPLICATION OF WAVELET ANALYSIS TO PLASMA FLUCTUATION STUDY ON GAMMA-10

A time-frequency analysis of plasma turbulence is performed for the GA MMA10 tandem mirror plasma. The method is based on the decomposition o f the reflectometer signal into a set of wavelets. Fast changes in the instantaneous spectra of fluctuations were observed in both the low-f requency (up to 50 kHz) and high-frequency (5-6 MHz) spectral regions. In order to estimate the propagation velocity of turbulent fluctuatio ns, a wavelet cross-correlation function was calculated. Comparison of wavelet spectra, corresponding to different reflectometer channels, d emonstrates the existence of short-time flashes of fluctuation intensi ty, as well as elongation of low-frequency disturbances along the magn etic field lines and their rotation in E x B direction.