Axisymmetric hybrid Vlasov equilibria with applications to tokamak plasmas

TL;DR

This paper derives axisymmetric equilibrium equations for hybrid Vlasov models with kinetic ions and fluid electrons, enabling the calculation of magnetic fields and ion distributions in tokamak plasmas with toroidal rotation and currents.

Contribution

It introduces a new equilibrium framework combining kinetic ions and fluid electrons, including a Grad-Shafranov PDE and an integral equation for plasma analysis.

Findings

Equilibrium equations account for toroidal plasma rotation.

Solutions include poloidal current density due to fluid electrons.

Equilibria differ from fully kinetic models by allowing poloidal currents.

Abstract

We derive axisymmetric equilibrium equations in the context of the hybrid Vlasov model with kinetic ions and massless fluid electrons, assuming isothermal electrons and deformed Maxwellian distribution functions for the kinetic ions. The equilibrium system comprises a Grad-Shafranov partial differential equation and an integral equation. These equations can be utilized to calculate the equilibrium magnetic field and ion distribution function, respectively, for given particle density or given ion and electron toroidal current density profiles. The resulting solutions describe states characterized by toroidal plasma rotation and toroidal electric current density. Additionally, due to the presence of fluid electrons, these equilibria also exhibit a poloidal current density component. This is in contrast to the fully kinetic Vlasov model, where axisymmetric Jeans equilibria can only accommodate toroidal currents and flows, given the absence of a third integral of the microscopic motion.