A self-consistent multi-component model of plasma turbulence and kinetic neutral dynamics for the simulation of the tokamak boundary

TL;DR

This paper introduces a comprehensive multi-component plasma and neutral dynamics model for tokamak boundary simulations, coupling plasma turbulence with neutral interactions to improve accuracy over single-component models.

Contribution

It develops a self-consistent multi-component plasma-neutral model using drift-reduced Braginskii equations and kinetic neutral equations, implemented in the GBS code for tokamak boundary simulations.

Findings

Multi-component model captures complex plasma-neutral interactions.

Simulation results differ significantly from single-component models.

Model provides a more accurate representation of tokamak boundary turbulence.

Abstract

A self-consistent model is presented for the simulation of a multi-component plasma in the tokamak boundary. A deuterium plasma is considered, with the plasma species that include electrons, deuterium atomic ions and deuterium molecular ions, while the deuterium atoms and molecules constitute the neutral species. The plasma and neutral models are coupled via a number of collisional interactions, which include dissociation, ionization, charge-exchange and recombination processes. The derivation of the three-fluid drift-reduced Braginskii equations used to describe the turbulent plasma dynamics is presented, including its boundary conditions. The kinetic advection equations for the neutral species are also derived, and their numerical implementation discussed. The first results of multi-component plasma simulations carried out by using the GBS code are then presented and analyzed, being compared with results obtained with the single-component plasma model.