# Flow Shear Suppression of Pedestal Turbulence--A First Principles Theoretical Framework

## TL;DR

This paper develops a first principles theoretical framework combining analytic and gyrokinetic simulations to predict how shear suppression affects pedestal turbulence in plasmas, especially in low-shear regimes relevant for future fusion devices.

## Contribution

It introduces a new physics-based theoretical model validated by simulations, extending understanding of shear suppression effects beyond current experimental regimes.

## Key findings

- Pedestal modes respond to shear suppression as predicted by decorrelation theory.
- Quantitative agreement between simulations and analytic predictions.
- Framework applicable to low-shear regimes in burning plasmas.

## Abstract

A combined analytic and computational gyrokinetic approach is developed to address the question of the scaling of pedestal turbulent transport with arbitrary levels of $E \times B$ shear. Due to strong gradients and shaping in the pedestal, the instabilities of interest are not curvature-driven like the core instabilities. By extensive numerical (gyrokinetic) simulations, it is demonstrated that pedestal modes respond to shear suppression very much like the predictions of a basic analytic decorrelation theory. The quantitative agreement between the two provides us with a new dependable, first principles (physics based) theoretical framework to predict the efficacy of shear suppression in burning plasmas that lie in a low-shear regime not accessed by present experiments.