Introduction to Gamma Processes
All processes of gamma interaction with media in Geant4 happen at the end of the step, so these interactions are discrete and corresponding processes are following the G4VDiscreteProcess interface.
General Interfaces
There are a number of similar functions for discrete electromagnetic processes and for electromagnetic (EM) packages an additional base classes were designed to provide common computations [JA09]. Common calculations for discrete EM processes are performed in the class G4VEmProcess. Derived classes (Table 1) are concrete processes providing initialisation. The physics models are implemented using the G4VEmModel interface. Each process may have one or many models defined to be active over a given energy range and set of G4Regions. Models are implementing computation of energy loss, cross section and sampling of final state. The list of EM processes and models for gamma incident is shown in Table 1.
EM process | EM model | Ref. |
---|---|---|
G4PhotoElectricEffect | G4PEEffectFluoModel | PhotoElectric Effect |
G4LivermorePhotoElectricModel | Livermore Model | |
G4LivermorePolarizedPhotoElectricModel | ||
G4PenelopePhotoElectricModel | Penelope Model | |
G4PolarizedPhotoElectricEffect | G4PolarizedPEEffectModel | Polarized Photoelectric Effect |
G4ComptonScattering | G4KleinNishinaCompton | Compton scattering |
G4KleinNishinaModel | Compton scattering | |
G4LivermoreComptonModel | Livermore Model | |
G4LivermoreComptonModelRC | ||
G4LivermorePolarizedComptonModel | Polarized Compton scattering | |
G4LowEPComptonModel | Monash University Low Energy Model | |
G4PenelopeComptonModel | Penelope Model | |
G4PolarizedCompton | G4PolarizedComptonModel | Polarized Compton scattering |
G4GammaConversion | G4BetheHeitlerModel | Gamma Conversion into e+e- Pair |
G4PairProductionRelModel | ||
G4LivermoreGammaConversionModel | Livermore Model | |
G4BoldyshevTripletModel | Livermore Triple Gamma Conversion | |
G4LivermoreNuclearGammaConversionModel | ||
G4LivermorePolarizedGammaConversionModel | ||
G4PenelopeGammaConversion | Penelope Model | |
G4PolarizedGammaConversion | G4PolarizedGammaConversionModel | Polarized Gamma conversion into an electron–positron pair |
G4RayleighScattering | G4LivermoreRayleighModel | Livermore Model |
G4LivermorePolarizedRayleighModel | ||
G4PenelopeRayleighModel | Penelope Model | |
G4GammaConversionToMuons | Gamma Conversion into Pair |
Bibliography
[JA09] | (1, 2) et al. J. Apostolakis. Geometry and physics of the geant4 toolkit for high and medium energy applications. Radiation Physics and Chemistry, 78(10):859–873, oct 2009. URL: https://doi.org/10.1016/j.radphyschem.2009.04.026, doi:10.1016/j.radphyschem.2009.04.026. |