Nonlinear equilibria and transport processes in burning plasmas

TL;DR

This paper develops a comprehensive phase-space transport theory for tokamak plasmas, introducing the concept of zonal states that self-consistently evolve with plasma fluctuations and sources, advancing understanding of plasma equilibrium and transport.

Contribution

It introduces a novel theoretical framework based on zonal states for modeling nonlinear plasma equilibria and transport processes in tokamaks, incorporating phase-space structures and electromagnetic fields.

Findings

Derivation of governing equations for phase-space zonal structures.

Application to geodesic acoustic modes and energetic particle modes.

Insights into nonlinear plasma equilibrium evolution.

Abstract

In this work, we put forward a general phase-space transport theory in axisymmetric tokamak plasmas based upon the concept of zonal state (ZS). Within this theoretical framework, the ZS corresponds to a renormalized plasma nonlinear equilibrium consisting of phase-space zonal structures (PSZS) and zonal electromagnetic fields (ZFs) which evolve self-consistently with symmetry breaking fluctuations and sources/collisions. More specifically, our approach involves deriving governing equations for the evolution of particle distribution functions (i.e, PSZS), which can be used to compute the corresponding macro-/meso-scale evolving magnetized plasma equilibrium adopting the Chew Goldberger Low (CGL) description, separating the spatiotemporal microscale structures. The nonlinear physics of ZFs and of geodesic acoustic modes/energetic particle driven geodesic acoustic modes is then analyzed to illustrate the implications of our theory.