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

Tracking and Physics• EM physics for simulation with high accuracy due to "UseDistanceToBoundary" multiple scatteringstep limitation, reduced finalRange parameter of stepping function optimized per particle type,G4WentzelVIModel for muon multiple scattering and G4IonParameterisedLossModel for ion ionisation (classname G4EmStandardPhysics_option3)• Combined Standard and Low-energy EM physics constructors based on the Option3 constructor; low-energymodels are applied below 1 GeV:• Models based on Livermore data bases for electrons and gamma (G4EmLivermorePhysics);• Polarized models based on Livermore data bases for electrons and gamma(G4EmLivermorePolarizedPhysics);• Penelope models for electrons, positrons and gamma (G4EmPenelopePhysics);• Low-energy DNA physics (G4EmDNAPhysics).Examples of the registration of these physics constructor and construction of alternative combinations of optionsare shown in novice, extended and advanced examples ($G4INSTALL/examples/extended/electromagnetic and$G4INSTALL/examples/advanced). Examples illustrating the use of electromagnetic processes are available aspart of the Geant4 release.Options are available for steering of electromagnetic processes. These options may be invoked either by UI commandsor by the interface class G4EmProcessOptions. This class has the following public methods:• SetLossFluctuations(G4bool)• SetSubCutoff(G4bool, const G4Region* r=0)• SetIntegral(G4bool)• SetMinSubRange(G4double)• SetMinEnergy(G4double)• SetMaxEnergy(G4double)• SetMaxEnergyForCSDARange(G4double)• SetMaxEnergyForMuons(G4double)• SetDEDXBinning(G4int)• SetDEDXBinningForCSDARange(G4int)• SetLambdaBinning(G4int)• SetStepFunction(G4double, G4double)• SetRandomStep(G4bool)• SetApplyCuts(G4bool)• SetSpline(G4bool)• SetBuildCSDARange(G4bool)• SetVerbose(G4int, const G4String name= "all")• SetLambdaFactor(G4double)• SetLinearLossLimit(G4double)• ActivateDeexcitation(G4bool val, const G4Region* r = 0)• SetMscStepLimitation(G4MscStepLimitType val)• SetMscLateralDisplacement(G4bool val)• SetSkin(G4double)• SetMscRangeFactor(G4double)• SetMscGeomFactor(G4double)• SetLPMFlag(G4bool)• SetBremsstrahlungTh(G4double)• SetPolarAngleLimit(G4double)• SetFactorForAngleLimit(G4double)The corresponding UI command can be accessed in the UI subdirectory "/process/eLoss". The following types ofstep limitation by multiple scattering are available:• fSimple - simplified step limitation as in g4 7.1 version (used in QGSP_BERT_EMV Physics List)• fUseSafety - default• fUseDistanceToBoundary - advance method of step limitation used in EM examples, required parameter skin> 0, should be used for setup without magnetic field151