Geant4

Infobox_Software | name = Geant4
developer = Geant4 Collaboration
latest_release_version = 9.1 p03
latest_release_date = September 19, 2008
operating_system = Cross-platform
genre = Computational physics
license = [http://cern.ch/geant4/license/LICENSE.html Geant4 Software License]
website = [http://geant4.org/]

Geant4 (for GEometry ANd Tracking) is a platform for "the simulation of the passage of particles through matter," using Monte Carlo methods. It is the successor of the GEANT series of software toolkits developed by CERN, and the first to use Object oriented programming (in C++). Its development, maintenance and user support are taken care by the international [http://geant4.org/ Geant4 Collaboration] . Application areas include high energy physics and nuclear experiments, medical, accelerator and space physics studies. The software is used by a number of research projects around the world.

The Geant4 software and source code is freely available from the project web site; until version 8.1 (released June 30, 2006), no specific software license for its use existed; Geant4 is now provided under the [http://cern.ch/geant4/license/LICENSE.html Geant4 Software License] .

Geant4 features

Geant4 includes facilities for handling geometry, tracking, detector response, run management, visualization and user interface. For many physics simulations, this means less time need be spent on the low level details, and researchers can start immediately on the more important aspects of the simulation.

Following is a summary of each of the facilities listed above:
* "Geometry" is an analysis of the physical layout of the experiment, including detectors, absorbers, etc., and considering how this layout will affect the path of particles in the experiment.
* "Tracking" is simulating the passage of a particle through matter. This involves considering possible interactions and decay processes.
* "Detector response" is recording when a particle passes through the volume of a detector, and approximating how a real detector would respond.
* "Run management" is recording the details of each "run" (a set of "events"), as well as setting up the experiment in different configurations between runs.
* Geant4 offers a number of options for "visualization", including OpenGL, and a familiar "user interface", based on Bash.

Geant4 can also optionally perform histogramming, but it requires external software that implements the AIDA framework in order to do so.

= Some high energy physics experiments using Geant4 =

* BaBar and GLAST at SLAC
* ATLAS, CMS and LHCb at LHC, CERN
* Borexino [http://borex.lngs.infn.it] at Gran Sasso Laboratory
* MINOS at Fermilab
* EXO

Geant4 applications outside high energy physics

Because of its general purpose nature, Geant4 is well suited for development of computational tools for analysing interactions of particle with matter in many areas. These include:
* Space applications [http://geant4.esa.int] where it is used to study interactions between the natural space radiation environment and space hardware or astronauts;
* Medical applications where interactions of radiations used for treatment are simulated.
* Radiation effects in microelectronics where ionizing effects on semiconductor devices are modeled.

See also

* CLHEP and FreeHEP, libraries for high energy physics

External links

* [http://geant4.org/ Official website]