Extended hybrid kinetic-magnetohydrodynamic model for ignited burning plasmas

TL;DR

This paper develops an extended hybrid kinetic-MHD model for ignited burning plasmas, improving the understanding of alpha particle effects across various dynamical regimes.

Contribution

It introduces a comprehensive kinetic-multifluid model and simplifies it into an extended hybrid kinetic-MHD model, broadening the applicability beyond existing pressure- and current-coupling schemes.

Findings

The pressure-coupling scheme is equivalent to the current-coupling scheme only in specific regimes.

The extended hybrid model accounts for significant alpha particle contributions.

Significant modifications to the generalized Ohm's law are identified.

Abstract

A brief review of the existing kinetic-magnetohydrodynamic(MHD) hybrid models for the alpha particle physics in burning plasma demonstrates that the pressure-coupling scheme is equivalent to the current-coupling scheme only in a specific dynamic regime where the alpha particle density is much lower than the background ion and electron. A more comprehensive kinetic-multifluid model is proposed for a proper account of the dynamical regime of the burning plasma where both the energetic alpha and the helium ash particles are present. The Kinetic-multifluid model is further simplified into an extended hybrid kinetic-MHD model in the MHD limit. This reduction process demonstrates that the existing pressure-coupling scheme is more extensive than the current-coupling scheme and sufficient for the wide range of dynamical regimes. This analysis further shows a significant change in the model equations mainly the generalized Ohm's law due to the contributions of a significant amount of alpha particles in the system. These models can be used for studies of the impact of the alpha particles present in ignited burning plasma and space plasma.