G4EmLowEPPhysics.cc

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// |                                                                   |
// | History:                                                          |
// | --------                                                          |
// |                                                                   |
// | Feb. 2021 JMCB  - Adapted for polarized gamma ray transport.      |
// |                   See "An electromagnetic physics constructor     |
// |                   for low energy polarised X-/gamma ray transport |
// |                   in Geant4", J. M. C. Brown and M. R. Dimmock,   |
// |                   arXiv:2102.02721 (2021).                        |
// |                   https://arxiv.org/abs/2102.02721                |
// |                                                                   |
// *********************************************************************
//
 
#include "G4EmLowEPPhysics.hh"
#include "G4ParticleDefinition.hh"
#include "G4SystemOfUnits.hh"
#include "G4ParticleTable.hh"
 
// *** Processes and models
 
// gamma
#include "G4PhotoElectricEffect.hh"
#include "G4LivermorePhotoElectricModel.hh"
#include "G4PhotoElectricAngularGeneratorPolarized.hh"
 
#include "G4ComptonScattering.hh"
#include "G4LowEPPolarizedComptonModel.hh"
 
#include "G4GammaConversion.hh"
#include "G4BetheHeitler5DModel.hh"
 
#include "G4RayleighScattering.hh" 
#include "G4LivermorePolarizedRayleighModel.hh"
 
#include "G4PEEffectFluoModel.hh"
#include "G4KleinNishinaModel.hh"
 
// e+-
#include "G4eMultipleScattering.hh"
#include "G4UniversalFluctuation.hh"
#include "G4ePairProduction.hh"
 
#include "G4eIonisation.hh"
#include "G4LivermoreIonisationModel.hh"
 
#include "G4eBremsstrahlung.hh"
#include "G4SeltzerBergerModel.hh"
#include "G4Generator2BS.hh"
 
// e+
#include "G4eplusAnnihilation.hh"
#include "G4PenelopeIonisationModel.hh"
 
// hadrons
#include "G4hMultipleScattering.hh"
#include "G4MscStepLimitType.hh"
 
#include "G4hIonisation.hh"
#include "G4ionIonisation.hh"
#include "G4IonParametrisedLossModel.hh"
#include "G4LindhardSorensenIonModel.hh"
#include "G4NuclearStopping.hh"
 
// msc models
#include "G4UrbanMscModel.hh"
#include "G4WentzelVIModel.hh"
#include "G4LowEWentzelVIModel.hh"
#include "G4GoudsmitSaundersonMscModel.hh"
#include "G4eCoulombScatteringModel.hh"
#include "G4CoulombScattering.hh"
 
// interfaces
#include "G4LossTableManager.hh"
#include "G4EmBuilder.hh"
#include "G4EmParameters.hh"
 
// particles
 
#include "G4Gamma.hh"
#include "G4Electron.hh"
#include "G4Positron.hh"
#include "G4GenericIon.hh"
 
//
#include "G4PhysicsListHelper.hh"
#include "G4BuilderType.hh"
#include "G4EmModelActivator.hh"
 
// factory
#include "G4PhysicsConstructorFactory.hh"
//
G4_DECLARE_PHYSCONSTR_FACTORY(G4EmLowEPPhysics);
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
G4EmLowEPPhysics::G4EmLowEPPhysics(G4int ver, const G4String&)
  : G4VPhysicsConstructor("G4EmLowEPPhysics")
{
  SetVerboseLevel(ver);
  G4EmParameters* param = G4EmParameters::Instance();
  param->SetDefaults();
  param->SetVerbose(ver);
  param->SetMinEnergy(100*CLHEP::eV);
  param->SetLowestElectronEnergy(100*CLHEP::eV);
  param->SetNumberOfBinsPerDecade(20);
  param->ActivateAngularGeneratorForIonisation(true);
  param->SetStepFunction(0.2, 100*CLHEP::um);
  param->SetStepFunctionMuHad(0.1, 50*CLHEP::um);
  param->SetStepFunctionLightIons(0.1, 20*CLHEP::um);
  param->SetStepFunctionIons(0.1, 1*CLHEP::um);
  param->SetUseMottCorrection(true);
  param->SetMscRangeFactor(0.04);   
  param->SetMuHadLateralDisplacement(true);
  param->SetFluo(true);
  param->SetAuger(true);
  param->SetUseICRU90Data(true);
  SetPhysicsType(bElectromagnetic);
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
G4EmLowEPPhysics::~G4EmLowEPPhysics()
{}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
void G4EmLowEPPhysics::ConstructParticle()
{
  // minimal set of particles for EM physics
  G4EmBuilder::ConstructMinimalEmSet();
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
void G4EmLowEPPhysics::ConstructProcess()
{
  if(verboseLevel > 1) {
    G4cout << "### " << GetPhysicsName() << " Construct Processes " << G4endl;
  }
  G4EmBuilder::PrepareEMPhysics();
 
  G4PhysicsListHelper* ph = G4PhysicsListHelper::GetPhysicsListHelper();
  G4EmParameters* param = G4EmParameters::Instance();
 
  // common processes
  G4hMultipleScattering* hmsc = new G4hMultipleScattering("ionmsc");
 
  // nuclear stopping
  G4double nielEnergyLimit = param->MaxNIELEnergy();
  G4NuclearStopping* pnuc = nullptr;
  if(nielEnergyLimit > 0.0) {
    pnuc = new G4NuclearStopping();
    pnuc->SetMaxKinEnergy(nielEnergyLimit);
  }
 
  // high energy limit for e+- scattering models and bremsstrahlung
  G4double highEnergyLimit = param->MscEnergyLimit();
 
  // Add gamma EM Processes
  G4ParticleDefinition* particle = G4Gamma::Gamma();
 
  // Photoelectric absorption
  G4PhotoElectricEffect* pe = new G4PhotoElectricEffect();
  G4VEmModel* theLivermorePEModel = new G4LivermorePhotoElectricModel();
  theLivermorePEModel->SetAngularDistribution(new G4PhotoElectricAngularGeneratorPolarized());
  pe->SetEmModel(theLivermorePEModel);
 
  // Compton scattering - Polarised Monash model  
  G4ComptonScattering* cs = new G4ComptonScattering;
  G4VEmModel* theLowEPCSModel = new G4LowEPPolarizedComptonModel();
  cs->SetEmModel(theLowEPCSModel);
 
  // gamma conversion - 5D model below 80 GeV with Livermore x-sections
  G4GammaConversion* theGammaConversion = new G4GammaConversion();
  G4VEmModel* conv = new G4BetheHeitler5DModel();
  theGammaConversion->SetEmModel(conv);
 
  // default Rayleigh scattering is Livermore
  G4RayleighScattering* theRayleigh = new G4RayleighScattering();
  G4VEmModel* theLivermorePRSModel = new G4LivermorePolarizedRayleighModel();
  theRayleigh->SetEmModel(theLivermorePRSModel);
 
  ph->RegisterProcess(pe, particle);
  ph->RegisterProcess(cs, particle);
  ph->RegisterProcess(theGammaConversion, particle);
  ph->RegisterProcess(theRayleigh, particle);
 
  // e-
  particle = G4Electron::Electron();
 
  // multiple scattering
  G4eMultipleScattering* msc = new G4eMultipleScattering();
  G4GoudsmitSaundersonMscModel* msc1 = new G4GoudsmitSaundersonMscModel();
  G4WentzelVIModel* msc2 = new G4WentzelVIModel();
  msc1->SetHighEnergyLimit(highEnergyLimit);
  msc2->SetLowEnergyLimit(highEnergyLimit);
  msc->SetEmModel(msc1);
  msc->SetEmModel(msc2);
 
  G4eCoulombScatteringModel* ssm = new G4eCoulombScatteringModel();
  G4CoulombScattering* ss = new G4CoulombScattering();
  ss->SetEmModel(ssm);
  ss->SetMinKinEnergy(highEnergyLimit);
  ssm->SetLowEnergyLimit(highEnergyLimit);
  ssm->SetActivationLowEnergyLimit(highEnergyLimit);
 
  // Ionisation - Livermore should be used only for low energies
  G4eIonisation* eioni = new G4eIonisation();
  G4LivermoreIonisationModel* theIoniLivermore = new G4LivermoreIonisationModel();
  theIoniLivermore->SetHighEnergyLimit(0.1*CLHEP::MeV); 
  eioni->AddEmModel(0, theIoniLivermore, new G4UniversalFluctuation() );
 
  // Bremsstrahlung
  G4eBremsstrahlung* brem = new G4eBremsstrahlung();
  G4SeltzerBergerModel* br1 = new G4SeltzerBergerModel();
  G4eBremsstrahlungRelModel* br2 = new G4eBremsstrahlungRelModel();
  br1->SetAngularDistribution(new G4Generator2BS());
  br2->SetAngularDistribution(new G4Generator2BS());
  brem->SetEmModel(br1);
  brem->SetEmModel(br2);
  br1->SetHighEnergyLimit(GeV);
 
  G4ePairProduction* ee = new G4ePairProduction();
 
  // register processes
  ph->RegisterProcess(msc, particle);
  ph->RegisterProcess(ss, particle);
  ph->RegisterProcess(eioni, particle);
  ph->RegisterProcess(brem, particle);
  ph->RegisterProcess(ee, particle);
 
  // e+
  particle = G4Positron::Positron();
 
  // multiple scattering
  msc = new G4eMultipleScattering();
  msc1 = new G4GoudsmitSaundersonMscModel();
  msc2 = new G4WentzelVIModel();
  msc1->SetHighEnergyLimit(highEnergyLimit);
  msc2->SetLowEnergyLimit(highEnergyLimit);
  msc->SetEmModel(msc1);
  msc->SetEmModel(msc2);
 
  ssm = new G4eCoulombScatteringModel();
  ss = new G4CoulombScattering();
  ss->SetEmModel(ssm);
  ss->SetMinKinEnergy(highEnergyLimit);
  ssm->SetLowEnergyLimit(highEnergyLimit);
  ssm->SetActivationLowEnergyLimit(highEnergyLimit);
 
  // Standard ionisation 
  eioni = new G4eIonisation();
  G4VEmModel* pen = new G4PenelopeIonisationModel();
  pen->SetHighEnergyLimit(0.1*MeV);
  eioni->AddEmModel(0, pen, new G4UniversalFluctuation());
 
  // Bremsstrahlung
  brem = new G4eBremsstrahlung();
  br1 = new G4SeltzerBergerModel();
  br2 = new G4eBremsstrahlungRelModel();
  br1->SetAngularDistribution(new G4Generator2BS());
  br2->SetAngularDistribution(new G4Generator2BS());
  brem->SetEmModel(br1);
  brem->SetEmModel(br2);
  br1->SetHighEnergyLimit(CLHEP::GeV);
 
  // register processes
  ph->RegisterProcess(msc, particle);
  ph->RegisterProcess(ss, particle);
  ph->RegisterProcess(eioni, particle);
  ph->RegisterProcess(brem, particle);
  ph->RegisterProcess(ee, particle);
  ph->RegisterProcess(new G4eplusAnnihilation(), particle);
 
  // generic ion
  particle = G4GenericIon::GenericIon();
       
  G4ionIonisation* ionIoni = new G4ionIonisation();
  G4VEmModel* mod = new G4LindhardSorensenIonModel();
  ionIoni->SetEmModel(mod);
 
  ph->RegisterProcess(hmsc, particle);
  ph->RegisterProcess(ionIoni, particle);
  if(nullptr != pnuc) { ph->RegisterProcess(pnuc, particle); }
 
  // muons, hadrons ions
  G4EmBuilder::ConstructCharged(hmsc, pnuc);
 
  // extra configuration
  G4EmModelActivator mact(GetPhysicsName());
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......