Getting started with Geant4

Geant4 is an open-source toolkit that enables to simulate particle passage through matter. It is written in C++ and offers a wide range of tools for users to employ in their applications. More information on the overview of the package can be found in the Introduction to Geant4.

Where can I find information on Geant4?

Geant4 is documented in several user guides that cover the installation, use of, and design/implementation of the toolkit.

Numerous example applications are distributed with each Geant4 release (under examples/), offering a demonstration of Geant4 capabilities across a broad range of use cases. Beginner users are invited to consult and use them as a base for their applications. More information on the examples can be found in the Examples Documentation and Application Developers Guide.

Geant4 tutorials are often held in various parts of the world. Consult the tutorials calendar to search for upcoming events, but also to have a look at past editions, which contain the educational material.

A moderated, news only mailing list is available if you wish to be notified about upcoming Geant4 releases, tutorials, and technical/user forums.

How do I install Geant4?

Geant4 can be used on Linux, macOS, and Windows (see supported and tested platforms).

Visit download page to get the latest Geant4 release.

Details on the requirements, installation steps, and post-installation setup are described in the Installation Guide.

Information on how to install your application, or Geant4 examples, can be found in the Application Developers Guide

How do I write an application using Geant4?

Geant4 is a toolkit, therefore it provides necessary tools for users to write their simulation applications. Consult Application Developers Guide to learn how Geant4 application should be structured, what elements are needed, and how to customise the application to your needs.

A set of example applications are distributed with Geant4 (under the examples/ directory in the source code ), to demonstrate the capabilities of the toolkit and a broad range of simulation use cases. Documentation and browsable source code for the examples can be found in the Examples Documentation.

More detailed information on advanced topics such as implementation of physics processes and the toolkit itself can be found in other user guides:

  • Physics Reference Manual describes physics interactions simulated in Geant4.
  • Physics List Guide is a brief guide over the pre-defined sets of physics interactions (called reference physics lists), and in particular differences in the electromagnetic options.
  • Toolkit Developers Guide covers more advanced topics, explaining the design of the toolkit, and information on how to extend it, e.g. by implementing a new physics process.

Frequently Asked Questions

Frequently asked questions are summarised in this guide.

Where can I get further help?

If you cannot find answer to your questions in the user guides or the examples and their documentation, try browsing the user forum to see if someone has already encountered a similar problem, otherwise, post it.

If you want to report a bug, please use Geant4 Problem Tracking System.