Editing Geant4

{{Short description|Scientific software for particle physics}}
{{Infobox software
| name                   = Geant4
| developer              = [https://cern.ch/geant4/collaboration Geant4 Collaboration]
| released               = {{Start date and age|1998}}<ref name="geant4"/>
| latest_release_version = 11.3.0
| latest_release_date    = {{Start date and age|2024|12|06}}
| operating_system       = [[Cross-platform]]
| genre                  = [[Computational physics]]
| license                = [https://geant4.org/download/license Geant4 Software License]
| website                = {{URL|http://geant4.org/}}
}}
[[Image:DAGATA-Detektor Monte Carlo Simulation with Geant4.png|thumb|Visualisation of a simulation. The detector is red and radiation is green.]]

'''Geant4'''<ref name="geant4">{{Cite journal|doi=10.1016/S0168-9002(03)01368-8|title=Geant4—a simulation toolkit|year=2003|last1=Agostinelli|first1=S.|last2=Allison|first2=J.|last3=Amako|first3=K.|last4=Apostolakis|first4=J.|last5=Araujo|first5=H.|last6=Arce|first6=P.|last7=Asai|first7=M.|last8=Axen|first8=D.|last9=Banerjee|first9=S.|last10=Barrand|first10=G.|last11=Behner|first11=F.|last12=Bellagamba|first12=L.|last13=Boudreau|first13=J.|last14=Broglia|first14=L.|last15=Brunengo|first15=A.|last16=Burkhardt|first16=H.|last17=Chauvie|first17=S.|last18=Chuma|first18=J.|last19=Chytracek|first19=R.|last20=Cooperman|first20=G.|last21=Cosmo|first21=G.|last22=Degtyarenko|first22=P.|last23=Dell'Acqua|first23=A.|last24=Depaola|first24=G.|last25=Dietrich|first25=D.|last26=Enami|first26=R.|last27=Feliciello|first27=A.|last28=Ferguson|first28=C.|last29=Fesefeldt|first29=H.|last30=Folger|first30=G.|journal=Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|volume=506|issue=3|pages=250|display-authors=15|bibcode = 2003NIMPA.506..250A |url=http://infoscience.epfl.ch/record/49909}}</ref><ref name="AllisonAmako2016">{{cite 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Fira|first75=A.|last76=Romano|first76=F.|last77=Russo|first77=G.|last78=Santin|first78=G.|last79=Sasaki|first79=T.|last80=Sawkey|first80=D.|last81=Shin|first81=J.I.|last82=Strakovsky|first82=I.I.|last83=Taborda|first83=A.|last84=Tanaka|first84=S.|last85=Tomé|first85=B.|last86=Toshito|first86=T.|last87=Tran|first87=H.N.|last88=Truscott|first88=P.R.|last89=Urban|first89=L.|last90=Uzhinsky|first90=V.|last91=Verbeke|first91=J.M.|last92=Verderi|first92=M.|last93=Wendt|first93=B.L.|last94=Wenzel|first94=H.|last95=Wright|first95=D.H.|last96=Wright|first96=D.M.|last97=Yamashita|first97=T.|last98=Yarba|first98=J.|last99=Yoshida|first99=H.|title=Recent developments in G eant 4|journal=Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|volume=835|year=2016|pages=186–225|issn=0168-9002|doi=10.1016/j.nima.2016.06.125|bibcode=2016NIMPA.835..186A|doi-access=free}}</ref><ref name="geant4-2">{{Cite journal|doi=10.1109/TNS.2006.869826|title=Geant4 developments and applications|year=2006|last1=Allison|first1=J.|last2=Amako|first2=K.|last3=Apostolakis|first3=J.|last4=Araujo|first4=H.|last5=Arce Dubois|first5=P.|last6=Asai|first6=M.|last7=Barrand|first7=G.|last8=Capra|first8=R.|last9=Chauvie|first9=S.|last10=Chytracek|first10=R.|last11=Cirrone|first11=G.A.P.|last12=Cooperman|first12=G.|last13=Cosmo|first13=G.|last14=Cuttone|first14=G.|last15=Daquino|first15=G.G.|last16=Donszelmann|first16=M.|last17=Dressel|first17=M.|last18=Folger|first18=G.|last19=Foppiano|first19=F.|last20=Generowicz|first20=J.|last21=Grichine|first21=V.|last22=Guatelli|first22=S.|last23=Gumplinger|first23=P.|last24=Heikkinen|first24=A.|last25=Hrivnacova|first25=I.|last26=Howard|first26=A.|last27=Incerti|first27=S.|last28=Ivanchenko|first28=V.|last29=Johnson|first29=T.|last30=Jones|first30=F.|journal=IEEE Transactions on Nuclear Science|volume=53|issue=1|pages=270–278|bibcode = 2006ITNS...53..270A |display-authors=15|hdl=2047/d20000660|url=https://cds.cern.ch/record/1035669/files/cer-002694037.pdf|hdl-access=free}}</ref><ref name="geant4-3">{{Cite journal|doi=10.1016/j.nima.2016.06.125|title=Recent developments in Geant4|year=2016|last1=Allison|first1=J.|last2=Amako|first2=K.|last3=Apostolakis|first3=J.|last4=Arce|first4=P.|last5=Asai|first5=M.|last6=Aso|first6=T.|last7=Bagli|first7=E.|last8=Bagulya|first8=A.|last9=Banerjee|first9=S.|last10=Barrand|first10=G.|last11=Beck|first11=B.R.|last12=Bogdanov|first12=A.G.|last13=Brandt|first13=D.|last14=Brown|first14=J.M.C.|last15=Burkhardt|first15=H.|last16=Canal|first16=Ph.|last17=Cano-Ott|first17=D.|last18=Chauvie|first18=S.|last19=Cho|first19=K.|last20=Cirrone|first20=G.A.P.|last21=Cooperman|first21=G.|last22=Cortés-Giraldo|first22=M.A.|last23=Cosmo|first23=G.|last24=Cuttone|first24=G.|last25=Depaola|first25=G.|last26=Desorgher|first26=L.|last27=Dong|first27=X.|last28=Dotti|first28=A.|last29=Elvira|first29=V.D.|last30=Folger|first30=G.|journal=Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|volume=835|pages=186–225|display-authors=15|bibcode = 2016NIMPA.835..186A |doi-access=free}}</ref> (for '''GEometry ANd Tracking''') is a [[Platform (computing)|platform]] for "the [[simulation]] of the passage of [[Elementary particle|particle]]s through [[matter]]" using [[Monte Carlo methods]].  It is the successor of the [[GEANT (program)|GEANT]] series of software toolkits developed by The Geant4 Collaboration, and the first to use [[object oriented programming]] (in [[C++]]). Its development, maintenance and user support are taken care by the international Geant4 Collaboration. Application areas include [[high energy physics]] and [[nuclear reaction|nuclear]] experiments, [[Particle accelerator|accelerator]] and [[space physics]] studies.<ref name="geant4-2"/> 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 28, 2006), no specific software license for its use existed; Geant4 is now provided under the Geant4 Software License.

== Features ==
Geant4 includes facilities for handling [[geometry]], tracking, [[particle detector|detector]] response, run management, visualization and [[user interface]].  For many physics simulations, this means less time needs to 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, [[absorber]]s, 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 [[Fundamental interaction|interaction]]s and [[Radioactive decay|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]], [[Open Inventor]], [[VRML]] or [[VTK]] and a familiar ''user interface'', based on [[tcsh]] or [[Qt_(software)|Qt]].

Geant4 can also perform basic histogramming; it requires external analysis tools for exploiting advanced histogramming features.

Since release 10.0, Geant4 implements [[thread (computing)|multithreading]],<ref name="geant4-3"/> making use of [[thread-local storage]] to allow for efficient generation of simulated events in parallel. Geant4 can be installed under a Unix-based operating system such as [[MacOS]], [[Linux]] or under [[Microsoft Windows]].

== Some high energy physics experiments using Geant4 ==
* [[BES III]] at BEPCII
* [[BaBar Experiment|BaBar]] and GLAST at [[SLAC]]
* [[A Toroidal LHC ApparatuS|ATLAS]], [[Compact Muon Solenoid|CMS]] and [[LHCb]] at [[Large Hadron Collider|LHC]], [[CERN]]
* [[COMPASS experiment|COMPASS]] at [[Super Proton Synchrotron|SPS]], [[CERN]]
* [[Borexino]] at [[Laboratori Nazionali del Gran Sasso|Gran Sasso Laboratory]]
* [[Deep Underground Neutrino Experiment|DUNE]], [[MINOS]], [[Muon g-2]], [[MicroBooNE]]/[[MiniBooNE]], and [[Mu2e]] at [[Fermilab]]
* [[Enriched Xenon Observatory]] (EXO)
* [[SNO+]]
* [[IceCube Neutrino Observatory|IceCube]]
* [[T2K]]
* [[CUORE]]
* Dark Matter Detectors: [[Cryogenic Dark Matter Search|SuperCDMS]], [[Large Underground Xenon experiment|LUX]], [[LZ experiment|LZ]], [[XENON]]

== Applications outside high energy physics ==
[[Image:RREA Monte Carlo simulation.png|thumb|right|400px|GEANT4 simulation of relativistic electron avalanche driven by an electric field in air as might occur in thunderstorms and lightning.]]
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<ref>http://geant4.esa.int </ref> where it is used to study interactions between the natural space radiation environment and space hardware or astronauts;
* Radiation effects in microelectronics where ionizing effects on semiconductor devices are modeled.
* Nuclear physics

== See also ==
* [[CLHEP]] and FreeHEP, libraries for high energy physics. 
* [[Accelerator physics codes]] for the modeling of charged particles in the rest of an accelerator.

== References ==
{{Reflist}}

== External links ==
* {{Official website|http://geant4.org/}}

{{Authority control}}

[[Category:Experimental particle physics]]
[[Category:Free science software]]
[[Category:Free software programmed in C++]]
[[Category:Monte Carlo particle physics software]]
[[Category:Physics software]]
[[Category:CERN software]]