Geant4 User's Guide for Application Developers - Geant4 - CERN

Tracking and Physics• Polarized Photo-electric effect (class G4LivermorePolarizedPhotoElectricModel)• Compton scattering (class G4LivermoreComptonModel)• Polarized Compton scattering (class G4LivermorePolarizedComptonModel)• Rayleigh scattering (class G4LivermoreRayleighModel)• Polarized Rayleigh scattering (class G4LivermorePolarizedRayleighModel)• Gamma conversion (also called pair production, class G4LivermoreGammaConversionModel)• Polarized gamma conversion (class G4LivermorePolarizedGammaConversionModel)• Electron models• Bremsstrahlung (class G4LivermoreBremsstrahlungModel)• Ionisation and delta ray production (class G4LivermoreIonisationModel)Options can be set in the G4LivermorePhotoElectricModel class, that allow the use of alternative photoelectronangular generators:• SetAngularGenerator(G4VPhotoElectricAngularDistribution* distribution);• SetAngularGenerator(const G4String& name);Currently three angular generators are available: G4PhotoElectricAngularGeneratorSimple,G4PhotoElectricAngularGeneratorSauterGavrilla and G4PhotoElectricAngularGeneratorPolarized.G4PhotoElectricAngularGeneratorSauterGavrilla is selected by default.G4PhotoElectricAngularGeneratorSimple, G4PhotoElectricAngularGeneratorSauterGavrilla andG4PhotoElectricAngularGeneratorPolarized can be set using respectively the strings "default", "standard" and"polarized".Options are available in the G4LivermoreBremsstrahlungModel class, that allow the use of alternativebremsstrahlung angular generators:• SetAngularGenerator(G4VBremAngularDistribution* distribution);• SetAngularGenerator(const G4String& name);Currently three angular generators are available: G4ModifiedTsai, 2BNGenerator and 2BSGenerator.G4ModifiedTsai is set by default, but it can be forced using the string "tsai". 2BNGenerator and 2BSGeneratorcan be set using the strings "2bs" and "2bn". Information regarding conditions of use, performance and energylimits of different models are available in the Physics Reference Manual .Other options G4LivermoreBremsstrahlungModel class are:• SetCutForLowEnSecPhotons(G4double)Options are available in the G4LivermoreIonisationModel class:• ActivateAuger(G4bool)• SetCutForLowEnSecPhotons(G4double)• SetCutForLowEnSecElectrons(G4double)5.2.1.2.2. ICRU73 based ion modelIonisation and delta ray production (class G4IonParametrisedLossModel)The ion model uses ICRU 73 stopping powers, if corresponding ion-material combinations are covered by theICRU 73 report (up to 1 GeV/nucleon), and otherwise applies a Bethe-Bloch based formalism. For compounds,ICRU 73 stopping powers are employed if the material name coincides with the name of Geant4 NIST materials(e.g. G4_WATER). Elemental materials are matched to the corresponding ICRU 73 stopping powers by meansof the atomic number of the material. The material name may be arbitrary in this case. For a list of applicablematerials, the user is referred to the ICRU 73 report.The model requires data files to be copied by the user to his/her code repository. These files are distributed togetherwith the Geant4 release. The user should set the environment variable G4LEDATA to the directory where he/she has copied the files.153