Effects of intermittency on turbulent transport in magnetized plasmas

Abstract

We analyze how the turbulent transport of $\mathbf{E}\times \mathbf{B}$ type in magnetically confined plasmas is affected by intermittent features of turbulence. The latter are captured by the non-Gaussian distribution $P(\phi)$ of the turbulent electric potential $\phi$. Our analysis is performed at an analytical level and confirmed numerically using two statistical approaches. We have found that the diffusion is inhibited linearly by intermittency, mainly via the kurtosis of the distribution $P(\phi)$. The associated susceptibility for this linear process is shown to be dependent on the poloidal velocity $V_p$ and on the correlation time $\tau_c$ with a maxima at the time-of-flight $\tau_{fl}$. Intermittency does not affect the Kubo number scaling in the strong regime.