Long-Range Time Correlations in Plasma Edge Turbulence

Analysis of the edge plasma fluctuation in several confinement devices reveals the self-similar character of the fluctuations through the presence of long-range time correlations. These results show that the tail of the autocorrelation function decays as a power law for time lags longer than the decorrelation time and as long as times on the order of the particle diffusion time. The algebraic decay of the longrange time correlations is consistent with plasma transport characterized by self-organized criticality. [S0031-9007(98)06077-3]