Charge-exchange source terms in magnetohydrodynamic plasmas

11th International Conference on Numerical Modeling of Space Plasma Flows

Destefano, Anthony M.^1 ; Heerikhuisen, Jacob^1

Department of Space Science, University of Alabama in Huntsville, United States^1

关键词: Boltzmann collision integral;    Charge exchanges;    Charge-exchange cross sections;    Heliospheres;    Laboratory datum;    Magnetohydrodynamic plasmas;    Source terms;    Space plasmas;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/837/1/012013/pdf
DOI  :  10.1088/1742-6596/837/1/012013

来源: IOP

【 摘 要 】

In the modeling of space plasma environments, source terms are often used to couple separate species of particles and/or fluids. There have been many techniques developed over the years to make such coupling more tractable while maintaining maximum physical fidelity. In our current application we use the formalism of the Boltzmann collision integral to compute source terms due to charge-exchange events in the heliosphere. The charge-exchange cross sections often encountered in heliospheric interactions can be fit to laboratory data, but in most cases cannot be directly integrated over analytically. Therefore, researchers often employ various levels of approximation, either semi-analytic or numerical. We explore several assumptions to the charge-exchange source term integrals, namely using Maxwellian velocity spaces for like-mass species and either hard-sphere, power-law, or exact forms of the cross section.