CRPropa is a public astrophysical simulation framework for propagating extraterrestrial ultra-high energy particles
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CRPropa is a publicly available code to study the propagation of ultra high energy nuclei up to iron on their voyage through an extra galactic environment. It takes into account: pion production, photodisintegration and energy losses by pair production of all relevant isotopes in the ambient low energy photon fields as well as nuclear decay. CRPropa can model the deflection in intergalactic magnetic fields, the propagation of secondary electromagnetic cascades and neutrinos for a multitude of scenarios for different source distributions and magnetic environments. It enables the user to predict the spectra of UHECR (and of their secondaries), their composition and arrival direction distribution.

This is the current version of CRPropa. It features a very flexible simulation setup, support for specialized extragalactic magnetic fields, galactic propagation and galactic lensing, python steering and shared-memory parallelization.

The official web site of CRPropa is

Try it out

You can try out CRPropa online at
Use the guest login and go to the CRPropa example via "VISPA Cluster" --> "Open Examples".

Installation and getting started

Installation instructions and documentation are found on the wiki page.
To get started we suggest to look at the tutorials and examples.


Please use the ticket system for support and in case of general questions. Please browse the wiki and previous support requests on installation and usage of CRPropa before opening a new ticket.

Howto cite CRPropa

If you use CRPropa 3 for your research, please cite:

JCAP 1605 (2016) no.05, 038; arXiv:1603.07142

In addition, depending on the features you use, please cite

  • for the DiffusionSDE module JCAP (2017) no.06, 046; arxiv:1704.07484
  • for the turbulent magnetic field with helicity Phys. Rev. D 94 (2016) no.08, 083005; arXiv:1607.00320
  • and for the magnetic lenses Astroparticle Physics 54 (2014), 110 arXiv:1302.3761.

Publications based on CRPropa

An extensive list of publications using CRPropa can be found via inSPIRE.