Signature of a universal statistical description for drift-wave plasma turbulence

TL;DR

This paper demonstrates that the probability density functions of intermittent plasma transport events in gyrokinetic simulations can be universally modeled using a fluid theoretical approach based on the instanton method, revealing a universal statistical signature.

Contribution

It introduces a universal statistical description for intermittent plasma turbulence PDFs using a fluid theoretical framework, bridging numerical simulations and theoretical modeling.

Findings

Numerical PDFs exhibit non-Gaussian tails with enhanced probabilities.

The PDFs match predictions from the instanton-based fluid theory after autocorrelation removal.

The results suggest a universal statistical behavior in plasma turbulence.

Abstract

This Letter provides a theoretical interpretation of numerically generated probability density functions (PDFs) of intermittent plasma transport events. Specifically, nonlinear gyrokinetic simulations of ion-temperature-gradient turbulence produce time series of heat flux which exhibit manifestly non-Gaussian PDFs with enhanced tails. It is demonstrated that, after the removal of autocorrelations, the numerical PDFs can be matched with predictions from a fluid theoretical setup, based on the instanton method. This result points to a universality in the modeling of intermittent stochastic process, offering predictive capability.