From Theoretical Foundation to Invaluable Research Tool: Modern Hybrid Simulations

TL;DR

This paper reviews hybrid simulation codes used in plasma physics, highlighting their foundation, numerical methods, and differences, emphasizing their role in modeling ion kinetics efficiently while approximating electron effects.

Contribution

It provides a comprehensive review of hybrid simulation codes, detailing their theoretical foundation, numerical implementation, and distinctions among various algorithms.

Findings

Hybrid codes effectively model ion kinetics in plasmas.

They are more efficient than full-particle simulations.

Hybrid codes are distinct from MHD models, balancing accuracy and computational cost.

Abstract

In many plasmas, in particular in space science, protons govern much of the essential physics. Minority ions, suprathermal tails, and electrons at times account for additional details. However, electron effects usually appear on much smaller spatial and temporal scales. For more than two decades, scientists have refined computational models that concentrate on the dominating and larger-scale ion kinetic physics, while treating the much lighter electrons as a charge-neutralizing fluid. These physics-based, algorithmic model descriptions are called hybrid codes, which have established an invaluable position for themselves - clearly distinct from MHD calculations, but simpler and much more efficient than full-particle simulations. Here, the foundation and numerical details of hybrid codes are reviewed, and differences between existing algorithms are elucidated.