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IF 7.2 2区物理与天体物理 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computer Physics Communications Pub Date : 2025-02-13 DOI:10.1016/j.cpc.2025.109542

Lukas Merten , Sophie Aerdker

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引用次数: 0

摘要

我们介绍了一种新代码，它极大地扩展了 CRPropa 的功能，可以模拟带电宇宙射线在湍流磁场中的集合平均传输。与之前的实现相比，新版本允许扩散张量的特征值在空间上变化，并允许实现与磁背景场相关的漂移。在这项工作中，我们给出了将通常以偏微分方程形式给出的传输方程转换为福克尔-普朗克方程，并进一步转换为相应的随机微分方程集的详细说明。此外，我们还对算法进行了详细测试，并对不同的不确定性来源进行了比较。因此，在某种程度上，这项工作可作为现有和即将开展的工作的技术参考，这些工作将使用基于 CRPropa 框架的新通用 SDE 求解器。此外，新的灵活性还使我们能够实施关于连续粒子喷射和聚焦俯仰角扩散的首个测试案例。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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Modeling Cosmic-Ray Transport: A CRPropa based stochastic differential equation solver

We present a new code that significantly extends CRPropa's capabilities to model the ensemble averaged transport of charged cosmic rays in turbulent magnetic fields. Compared with previous implementations, the new version allows for spatially varying Eigenvalues of the diffusion tensor and for the implementation of drifts associated with the magnetic background field. The software is based on solving a set of stochastic differential equations (SDEs).

In this work we give detailed instructions to transform a transport equation, usually given as a partial differential equation, into a Fokker-Planck equation and further into the corresponding set of SDEs. Furthermore, detailed tests of the algorithms are done and different sources of uncertainties are compared to each other. So to some extent, this work serves as a technical reference for existing and upcoming work using the new generalized SDE solver based on the CRPropa framework.

Furthermore, the new flexibility allowed us to implement first test cases on continuous particle injection and focused pitch angle diffusion.

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来源期刊

Computer Physics Communications 物理-计算机：跨学科应用

CiteScore

12.10

自引率

3.20%

发文量

287

审稿时长

5.3 months

期刊介绍： The focus of CPC is on contemporary computational methods and techniques and their implementation, the effectiveness of which will normally be evidenced by the author(s) within the context of a substantive problem in physics. Within this setting CPC publishes two types of paper. Computer Programs in Physics (CPiP) These papers describe significant computer programs to be archived in the CPC Program Library which is held in the Mendeley Data repository. The submitted software must be covered by an approved open source licence. Papers and associated computer programs that address a problem of contemporary interest in physics that cannot be solved by current software are particularly encouraged. Computational Physics Papers (CP) These are research papers in, but are not limited to, the following themes across computational physics and related disciplines. mathematical and numerical methods and algorithms; computational models including those associated with the design, control and analysis of experiments; and algebraic computation. Each will normally include software implementation and performance details. The software implementation should, ideally, be available via GitHub, Zenodo or an institutional repository.In addition, research papers on the impact of advanced computer architecture and special purpose computers on computing in the physical sciences and software topics related to, and of importance in, the physical sciences may be considered.