Sapphire++: A particle transport code combining a spherical harmonic expansion and the discontinuous Galerkin method

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Schween, Nils W., Schulze, Florian, Reville, Brian
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916558747467776
author Schween, Nils W.
Schulze, Florian
Reville, Brian
author_facet Schween, Nils W.
Schulze, Florian
Reville, Brian
contents We present Sapphire++, an open-source code designed to numerically solve the Vlasov-Fokker-Planck equation for astrophysical applications. Sapphire++ employs a numerical algorithm based on a spherical harmonic expansion of the distribution function, expressing the Vlasov-Fokker-Planck equation as a system of partial differential equations governing the evolution of the expansion coefficients. The code utilises the discontinuous Galerkin method in conjunction with implicit and explicit time stepping methods to compute these coefficients, providing significant flexibility in its choice of spatial and temporal accuracy. We showcase the code's validity using examples. In particular, we simulate the acceleration of test particles at a parallel shock and compare the results to analytical predictions. The Sapphire++ code (https://github.com/sapphirepp/sapphirepp) is available as a free and open-source tool for the community.
format Preprint
id arxiv_https___arxiv_org_abs_2501_05110
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Sapphire++: A particle transport code combining a spherical harmonic expansion and the discontinuous Galerkin method
Schween, Nils W.
Schulze, Florian
Reville, Brian
High Energy Astrophysical Phenomena
Instrumentation and Methods for Astrophysics
Plasma Physics
We present Sapphire++, an open-source code designed to numerically solve the Vlasov-Fokker-Planck equation for astrophysical applications. Sapphire++ employs a numerical algorithm based on a spherical harmonic expansion of the distribution function, expressing the Vlasov-Fokker-Planck equation as a system of partial differential equations governing the evolution of the expansion coefficients. The code utilises the discontinuous Galerkin method in conjunction with implicit and explicit time stepping methods to compute these coefficients, providing significant flexibility in its choice of spatial and temporal accuracy. We showcase the code's validity using examples. In particular, we simulate the acceleration of test particles at a parallel shock and compare the results to analytical predictions. The Sapphire++ code (https://github.com/sapphirepp/sapphirepp) is available as a free and open-source tool for the community.
title Sapphire++: A particle transport code combining a spherical harmonic expansion and the discontinuous Galerkin method
topic High Energy Astrophysical Phenomena
Instrumentation and Methods for Astrophysics
Plasma Physics
url https://arxiv.org/abs/2501.05110