Magnetohydrodynamic/Kinetic Modeling of the Interaction between the Solar Wind and the Local Interstellar Medium with He$^+$, He$^{2+}$, and Pickup H$^+$ ions and H, He Atoms

TL;DR

This paper introduces an advanced MHD-kinetic model of the solar wind and interstellar medium interaction, incorporating multiple ion populations and charge exchange processes to better understand the heliosphere's structure.

Contribution

The paper presents a novel extension of the MS-FLUKSS model that self-consistently includes multiple ion species and charge exchange interactions, enhancing heliospheric simulations.

Findings

Successfully implemented the new multi-ion model.

Demonstrated detailed charge exchange processes.

Validated model performance with initial tests.

Abstract

The interaction of the solar wind with the local interstellar medium (LISM) spans a wide range of interacting particle populations, energies, and scales. Sophisticated models are required to capture the global picture, interpret near-Earth observations, and ultimately understand the properties of the LISM at distances of thousands of AUs, where the medium is presumed to be unperturbed by this interaction. We present a new extension of our MHD-plasma/kinetic-neutral heliospheric model, implemented within the Multi-Scale Fluid-Kinetic Simulation Suite (MS-FLUKSS). The new model treats singly and doubly charged helium ions, pickup protons, and electrons as separate, self-consistently coupled populations, interacting through six charge exchange processes and photoionization with kinetically treated neutral hydrogen and helium atoms. In this paper, we provide detailed information on the implementation, including new fits for the charge-exchange cross sections, and demonstrate the functionality and performance of the new code.