Non-perturbative statistical theory of intermittency in ITG drift wave turbulence with zonal flows

TL;DR

This paper develops a non-perturbative statistical theory to analyze intermittency in ITG drift wave turbulence, focusing on the role of shear flows and zonal flows in regulating turbulence and transport.

Contribution

It introduces a novel non-perturbative approach to describe the PDFs of momentum flux and zonal flow formation in ITG turbulence, incorporating shear flow effects.

Findings

Shear flow can suppress high transport levels in ITG turbulence.

Zonal flows are more likely to form further from marginal stability.

Increased shear flow enhances the self-regulating behavior of turbulence.

Abstract

The probability distribution functions (PDFs) of momentum flux and zonal flow formation in ion-temperature-gradient (ITG) turbulence are investigated, including the effect of the shear flow on the PDFs. While ITG turbulence maintains high level of transport, this may be suppressed by shear flow. Zonal flows are also shown here to have an enhanced likelihood of generation further from marginal stability which will then regulate the ITG turbulence, which is more prominent with increased shear flow, leading to a self-regulating system.