Properties of Turbulence and Stationary Zonal Flow on Transport Barrier in CHS

Spectral changes in electric field fluctuation are measured using twin heavy ion beam probes in CHS before and after an internal transport barrier is broken down. A wavelet analysis reveals intermittent behaviors of the fluctuations, and a significant correlation between fluctuation powers of the low (2.5 < f < 10 kHz) and high (30 < f < 250 kHz) ranges. The high frequency (turbulence) fluctuation increases with a decrease in the low frequency fluctuation after the back-transition. The change in the power distribution between these two frequency ranges may contribute to the improved transport on the barrier