# On the interplay between turbulent forces and neoclassical particle losses in Zonal Flow dynamics

## TL;DR

This paper investigates how turbulent forces and neoclassical particle losses interact to influence Zonal Flow dynamics in the TJ-II stellarator, highlighting the complex interplay between turbulence and neoclassical effects.

## Contribution

It provides new insights into the relationship between radial electric fields, Reynolds stress, and Zonal Flows, emphasizing the limited role of turbulent acceleration alone.

## Key findings

- Radial electric fields affect neoclassical orbit losses.
- Turbulent acceleration is comparable to neoclassical damping.
- Turbulent acceleration is not correlated with LRC amplitude.

## Abstract

This study presents the investigation of the connection between radial electric field, gradient of Reynolds stress and Long Range Correlation (LRC), as a proxy for Zonal Flows (ZF), in different plasma scenarios in the TJ-II stellarator. Monte Carlo simulations were made showing that radial electric fields in the range of those experimentally measured have an effect on the neoclassical orbit losses. The results indicate that, despite the order of magnitude of turbulent acceleration is comparable to the neoclassical damping of perpendicular flows, its dependence with radial electric field is not correlated with the evolution of LRC amplitude, indicating that turbulent acceleration alone cannot explain the dynamics of Zonal Flows. These results are in line with the expectation that the interplay between turbulent and neoclassical mechanisms is a crucial ingredient of the dynamics of edge Zonal Flows.