# CRPropa - A Toolbox for Cosmic Ray Simulations

## TL;DR

CRPropa is a comprehensive simulation framework designed to model cosmic ray propagation and acceleration, incorporating recent improvements for both extragalactic and galactic cosmic rays, aiding astrophysical data interpretation.

## Contribution

The paper introduces new modules and features in CRPropa, including a differential transport solver and enhanced secondary particle simulations, expanding its capabilities for cosmic ray research.

## Key findings

- Enhanced simulation accuracy for cosmic ray propagation.
- New modules for galactic and extragalactic cosmic rays.
- Improved modeling of electromagnetic secondaries.

## Abstract

The astrophysical interpretation of recent experimental observations of cosmic rays relies increasingly on Monte Carlo simulations of cosmic ray propagation and acceleration. Depending on the energy range of interest, several different propagation effects inside the Milky Way as well as in extragalactic space have to be taken into account when interpreting the data. With the CRPropa framework we aim to provide a toolbox for according simulations. In recent versions of CRPropa, the ballistic single particle propagation mode aiming primarily at extragalactic cosmic rays has been complemented by a solver for the differential transport equation to address propagation of galactic cosmic rays. Additionally, modules have been developed to address cosmic ray acceleration and many improvements have been added for simulations of electromagnetic secondaries. In this contribution we will give an overview of the CRPropa simulation framework with a focus on the latest improvements and highlight selected features by example applications.