A Hamiltonian Five-Field Gyrofluid Model

TL;DR

This paper introduces a Hamiltonian five-field gyrofluid model incorporating magnetic curvature effects, providing a Hamiltonian structure, invariants, and stability analysis relevant for plasma physics.

Contribution

It presents a novel Hamiltonian formulation of a five-field gyrofluid model including magnetic curvature effects, with derived invariants and stability criteria.

Findings

Hamiltonian structure established for the model

Derived stability criteria and dispersion relations

Compared fluid and kinetic model results

Abstract

A Lie-Poisson bracket is presented for a five-field gyrofluid model, thereby showing the model to be Hamiltonian. The model includes the effects of magnetic field curvature and describes the evolution of the electron and ion gyro-center densities, the parallel component of the ion and electron velocities, and the ion temperature. The quasineutrality property and Ampere's law determine respectively the electrostatic potential and magnetic flux. The Casimir invariants are presented, and shown to be associated to five Lagrangian invariants advected by distinct velocity fields. A linear, local study of the model is conducted both with and without Landau and diamagnetic resonant damping terms. Stability criteria and dispersion relations for the electrostatic and the electromagnetic cases are derived and compared with their analogs for fluid and kinetic models.