GEANT is the name of a series of simulation software designed to describe the passage of

elementary particles In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. Particles currently thought to be elementary include electrons, the fundamental fermions (quarks, leptons, antiqu ...

through matter, using

Monte Carlo method Monte Carlo methods, or Monte Carlo experiments, are a broad class of computational algorithms that rely on repeated random sampling to obtain numerical results. The underlying concept is to use randomness to solve problems that might be determi ...

s. The name is an

acronym An acronym is a word or name formed from the initial components of a longer name or phrase. Acronyms are usually formed from the initial letters of words, as in ''NATO'' (''North Atlantic Treaty Organization''), but sometimes use syllables, as ...

formed from "GEometry ANd Tracking". Originally developed at

CERN The European Organization for Nuclear Research, known as CERN (; ; ), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in a northwestern suburb of Gene ...

for

high energy physics Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) and b ...

experiments, GEANT-3 has been used in many other fields.

History

The very first version of GEANT dates back to 1974, while the first version of GEANT-3 dates back to 1982. Versions of GEANT through 3.21 were written in FORTRAN and eventually maintained as part of CERNLIB. Since about 2000, the last FORTRAN release has been essentially in stasis and receives only occasional bug fixes. GEANT3 was, however, still in use by some experiments for some time thereafter. Most of GEANT-3 is available under the

GNU General Public License The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the Four Freedoms (Free software), four freedoms to run, study, share, and modify the software. The license was th ...

, with the exception of some hadronic interaction code contributed by the FLUKA collaboration. GEANT-3 was used by a majority of high energy physics experiments from the late 1980s to the early 2000s. The largest experiments using were three of the experiments at the Large Electron-Positron collider, including

ALEPH Aleph (or alef or alif, transliterated ʾ) is the first letter of the Semitic abjads, including Phoenician , Hebrew , Aramaic , Syriac , Arabic ʾ and North Arabian 𐪑. It also appears as South Arabian 𐩱 and Ge'ez . These letter ...

, L3 and

OPAL Opal is a hydrated amorphous form of silica (SiO2·''n''H2O); its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Due to its amorphous property, it is classified as a mineraloid, unlike crystalline forms ...

. It was also a key tool in the design and optimization of the detectors of all experiments at the Large Hadron Collider (LHC) – see e.g. the ATLA
Technical Design Report
GEANT-3.21 based programs remained main simulation engine of ATLAS, CMS and LHCb at LHC until 2004, when these experiments moved to Geant4-based simulations. Even in 2019 it remains the primary simulation tool for the ALICE experiment at the LHC. A related (but separate) product is

Geant4 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 bThe Geant4 Collaboration and t ...

(when referring to this version, the name is typically no longer capitalized). It is a complete rewrite in

C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...

with a modern

object-oriented Object-oriented programming (OOP) is a programming paradigm based on the concept of "objects", which can contain data and code. The data is in the form of fields (often known as attributes or ''properties''), and the code is in the form of pro ...

design. Geant4 was developed by the RD44 collaboration in 1994–1998 and is being maintained and improved now by the Geant4 international collaboration. For quite some time Geant4 did not have a clearly defined software license. As of version 8.1 (released June 30, 2006) this omission has been remedied. Geant4 is now available under th
Geant4 Software License

References

{{Reflist

External links

Geant4
publicly accessible webpage
GEANT
webpage at CERN (only available to CERN users) Free software programmed in Fortran Monte Carlo particle physics software Physics software CERN software

History

See also

References

External links