On the particle and electromagnetic boundary conditions in a mesothermal plasma flow
Abstract
The fully kinetic modeling of mesothermal plasma flows presents significant challenges in the description of boundary conditions for the electrons and the electromagnetic field. Due to their higher mobility compared to ions, electrons extend downstream of the ions, which hinders the implementation of the outflow boundary conditions during transient states. Although the electron drift velocity, ue, is usually neglected as ue ≃ ui < vth,e, where ui is the bulk velocity of the ions and vth,e is the thermal velocity of the electrons, we will show how accounting for it, both at the injection of particles and at the outflow boundary condition, is of great importance to achieve quasi-neutrality of charge and current densities. A new partial reflection model for electrons is presented to represent quasi-steady and transitory states. Additionally, we will show how we can employ Ampere-Maxwell's law to better represent the transitory electric field at the outflow boundary compared to the classical `zero-field' Neumann boundary without requiring any numerical parameters. With these new boundary conditions, we improve the quasi-steady and transitory descriptions of expanding mesothermal plasmas.
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BibTeX
@misc{gonzalez2026particle,
title = {{On the particle and electromagnetic boundary conditions in a mesothermal plasma flow}},
author = {J. Gonzalez},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.09948},
eprint = {2610.09948},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.09948},
}
RIS
TY - UNPB
TI - On the particle and electromagnetic boundary conditions in a mesothermal plasma flow
AU - J. Gonzalez
PY - 2026
DA - 2026/10/07
PB - arXiv
DO - 10.48550/arxiv.2610.09948
UR - https://arxiv.org/abs/2610.09948
AB - The fully kinetic modeling of mesothermal plasma flows presents significant challenges in the description of boundary conditions for the electrons and the electromagnetic field. Due to their higher mobility compared to ions, electrons extend downstream of the ions, which hinders the implementation of the outflow boundary conditions during transient states. Although the electron drift velocity, u_e, is usually neglected as u_e ≃ u_i < v_th,e, where u_i is the bulk velocity of the ions and v_th,e is the thermal velocity of the electrons, we will show how accounting for it, both at the injection of particles and at the outflow boundary condition, is of great importance to achieve quasi-neutrality of charge and current densities. A new partial reflection model for electrons is presented to represent quasi-steady and transitory states. Additionally, we will show how we can employ Ampere-Maxwell's law to better represent the transitory electric field at the outflow boundary compared to the classical `zero-field' Neumann boundary without requiring any numerical parameters. With these new boundary conditions, we improve the quasi-steady and transitory descriptions of expanding mesothermal plasmas.
ER -