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.

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

Installation instructions and documentation are found on the wiki page.

If you have general questions or encounter any problems during installation or when running CRPropa, please use the ticket system.