G4BGGPionInelasticXS.cc

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// $Id$
//
// -------------------------------------------------------------------
//
// GEANT4 Class file
//
//
// File name:     G4BGGPionInelasticXS
//
// Author:        Vladimir Ivanchenko
//
// Creation date: 01.10.2003
// Modifications:
//
// -------------------------------------------------------------------
//
 
#include "G4BGGPionInelasticXS.hh"
#include "G4SystemOfUnits.hh"
#include "G4GlauberGribovCrossSection.hh"
#include "G4UPiNuclearCrossSection.hh"
#include "G4HadronNucleonXsc.hh"
//#include "G4HadronInelasticDataSet.hh"
#include "G4ComponentSAIDTotalXS.hh"
 
#include "G4Proton.hh"
#include "G4PionPlus.hh"
#include "G4PionMinus.hh"
#include "G4NistManager.hh"
 
 
G4BGGPionInelasticXS::G4BGGPionInelasticXS(const G4ParticleDefinition* p) 
 : G4VCrossSectionDataSet("Barashenkov-Glauber-Gribov")
{
  verboseLevel = 0;
  fGlauberEnergy = 91.*GeV;
  fLowEnergy = 20.*MeV;
  fSAIDHighEnergyLimit = 2.6*GeV;
  SetMinKinEnergy(0.0);
  SetMaxKinEnergy(100*TeV);
 
  for (G4int i = 0; i < 93; i++) {
    theGlauberFac[i] = 0.0;
    theCoulombFac[i] = 0.0;
    theA[i] = 1;
  }
  fPion = 0;
  fGlauber = 0;
  fHadron  = 0;
  //  fGHEISHA = 0;
  fSAID    = 0;
  particle = p;
  theProton= G4Proton::Proton();
  isPiplus = false;
  isInitialized = false;
}
 
 
G4BGGPionInelasticXS::~G4BGGPionInelasticXS()
{
  delete fGlauber;
  delete fPion;
  delete fHadron;
  delete fSAID;
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
G4bool 
G4BGGPionInelasticXS::IsElementApplicable(const G4DynamicParticle*, G4int,
                      const G4Material*)
{
  return true;
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
G4bool G4BGGPionInelasticXS::IsIsoApplicable(const G4DynamicParticle*, 
                         G4int Z, G4int A,  
                         const G4Element*,
                         const G4Material*)
{
  return (1 == Z && 2 >= A);
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
G4double
G4BGGPionInelasticXS::GetElementCrossSection(const G4DynamicParticle* dp,
                         G4int ZZ, const G4Material*)
{
  // this method should be called only for Z > 1
 
  G4double cross = 0.0;
  G4double ekin = dp->GetKineticEnergy();
  G4int Z = ZZ;
  if(1 == Z) {
    cross = 1.0115*GetIsoCrossSection(dp,1,1);
  } else {
    if(Z > 92) { Z = 92; }
 
    if(ekin <= fLowEnergy && !isPiplus) {
      cross = theCoulombFac[Z];
    } else if(ekin <= 2*MeV && isPiplus) {
      cross = theCoulombFac[Z]*CoulombFactor(ekin, Z);  
    } else if(ekin > fGlauberEnergy) {
      cross = theGlauberFac[Z]*fGlauber->GetInelasticGlauberGribov(dp, Z, theA[Z]);
    } else {
      cross = fPion->GetInelasticCrossSection(dp, Z, theA[Z]);
    }
  }
  if(verboseLevel > 1) {
    G4cout << "G4BGGPionInelasticXS::GetCrossSection  for "
       << dp->GetDefinition()->GetParticleName()
       << "  Ekin(GeV)= " << dp->GetKineticEnergy()
       << " in nucleus Z= " << Z << "  A= " << theA[Z]
       << " XS(b)= " << cross/barn 
       << G4endl;
  }
  return cross;
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
G4double
G4BGGPionInelasticXS::GetIsoCrossSection(const G4DynamicParticle* dp, 
                     G4int Z, G4int A, 
                     const G4Isotope*,
                     const G4Element*,
                     const G4Material*)
{
  // this method should be called only for Z = 1
 
  G4double cross = 0.0;
  G4double ekin = dp->GetKineticEnergy();
 
  if(ekin <= fSAIDHighEnergyLimit) {
    cross = fSAID->GetInelasticIsotopeCrossSection(particle, ekin, 1, 1);
  } else {
    fHadron->GetHadronNucleonXscPDG(dp, theProton);
    cross = (theCoulombFac[1]/ekin + 1)*fHadron->GetInelasticHadronNucleonXsc();
  } 
  /*
  if(isPiplus) { 
    if(ekin <= 20*GeV) {
      cross = theCoulombFac[1]*fGHEISHA->GetElementCrossSection(dp, 1, mat);
    } else {
      fHadron->GetHadronNucleonXscPDG(dp, theProton);
      cross = fHadron->GetInelasticHadronNucleonXsc();
    }
  } else {
    if(ekin <= fLowEnergy) {
      cross = theCoulombFac[1];
    } else if(ekin <= 20*GeV) {
      fHadron->GetHadronNucleonXscNS(dp, theProton);
      cross = theGlauberFac[1]*fHadron->GetInelasticHadronNucleonXsc();
    } else {
      fHadron->GetHadronNucleonXscPDG(dp, theProton);
      cross = fHadron->GetInelasticHadronNucleonXsc();
    }
  }
  */
  cross *= A;
 
  if(verboseLevel > 1) {
    G4cout << "G4BGGPionInelasticXS::GetCrossSection  for "
       << dp->GetDefinition()->GetParticleName()
       << "  Ekin(GeV)= " << dp->GetKineticEnergy()
       << " in nucleus Z= " << Z << "  A= " << A
       << " XS(b)= " << cross/barn 
       << G4endl;
  }
  return cross;
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
void G4BGGPionInelasticXS::BuildPhysicsTable(const G4ParticleDefinition& p)
{
  if(&p == G4PionPlus::PionPlus() || &p == G4PionMinus::PionMinus()) {
    particle = &p;
  } else {
    G4cout << "### G4BGGPionInelasticXS WARNING: is not applicable to " 
       << p.GetParticleName()
       << G4endl;
    throw G4HadronicException(__FILE__, __LINE__,
      "G4BGGPionInelasticXS::BuildPhysicsTable is used for wrong particle");
    return;
  }
 
  if(isInitialized) { return; }
  isInitialized = true;
 
  fPion    = new G4UPiNuclearCrossSection();
  fGlauber = new G4GlauberGribovCrossSection();
  fHadron  = new G4HadronNucleonXsc();
  //  fGHEISHA = new G4HadronInelasticDataSet();
  fSAID    = new G4ComponentSAIDTotalXS();
 
  fPion->BuildPhysicsTable(*particle);
  fGlauber->BuildPhysicsTable(*particle);
  if(particle == G4PionPlus::PionPlus()) { isPiplus = true; }
 
  G4ParticleDefinition* part = const_cast<G4ParticleDefinition*>(particle);
  G4ThreeVector mom(0.0,0.0,1.0);
  G4DynamicParticle dp(part, mom, fGlauberEnergy);
 
  G4NistManager* nist = G4NistManager::Instance();
 
  G4double csup, csdn;
  G4int A;
 
  if(verboseLevel > 0) {
    G4cout << "### G4BGGPionInelasticXS::Initialise for "
       << particle->GetParticleName()
       << " isPiplus: " << isPiplus
       << G4endl;
  }
 
  for(G4int iz=2; iz<93; iz++) {
 
    A = G4lrint(nist->GetAtomicMassAmu(iz));
    theA[iz] = A;
 
    csup = fGlauber->GetInelasticGlauberGribov(&dp, iz, A);
    csdn = fPion->GetInelasticCrossSection(&dp, iz, theA[iz]);
 
    theGlauberFac[iz] = csdn/csup;
    if(verboseLevel > 0) {
      G4cout << "Z= " << iz <<  "  A= " << A 
         << " factor= " << theGlauberFac[iz] << G4endl; 
    }
  }
  dp.SetKineticEnergy(fSAIDHighEnergyLimit);
  fHadron->GetHadronNucleonXscPDG(&dp, theProton);
  theCoulombFac[1] = fSAIDHighEnergyLimit*
    (fSAID->GetInelasticIsotopeCrossSection(particle,fSAIDHighEnergyLimit,1,1)
     /fHadron->GetInelasticHadronNucleonXsc() - 1);
 
  /*
  dp.SetKineticEnergy(20*GeV);
  const G4Material* mat = 0;
  if(isPiplus) { 
    fHadron->GetHadronNucleonXscPDG(&dp, theProton);
    theCoulombFac[1] = fHadron->GetInelasticHadronNucleonXsc()
      /fGHEISHA->GetElementCrossSection(&dp, 1, mat);
  } else {
    fHadron->GetHadronNucleonXscPDG(&dp, theProton);
    theGlauberFac[1] = fHadron->GetInelasticHadronNucleonXsc();
    fHadron->GetHadronNucleonXscNS(&dp, theProton);
    theGlauberFac[1] /= fHadron->GetInelasticHadronNucleonXsc();
  }
  */ 
  if(isPiplus) { 
    dp.SetKineticEnergy(2*MeV);
    for(G4int iz=2; iz<93; iz++) {
      theCoulombFac[iz] = fPion->GetInelasticCrossSection(&dp, iz, theA[iz])
    /CoulombFactor(2*MeV,iz); 
    }
 
  } else {
    dp.SetKineticEnergy(fLowEnergy);
    //fHadron->GetHadronNucleonXscNS(&dp, theProton);
    //theCoulombFac[1] = theGlauberFac[1]*fHadron->GetInelasticHadronNucleonXsc();
    for(G4int iz=2; iz<93; iz++) {
      theCoulombFac[iz] = fPion->GetInelasticCrossSection(&dp, iz, theA[iz]);
    }
  }
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
G4double G4BGGPionInelasticXS::CoulombFactor(G4double kinEnergy, G4int Z)
{
  G4int A = theA[Z];
  G4double res= 0.0;
  if(kinEnergy <= DBL_MIN) { return res; }
  else if(A < 2) { return kinEnergy*kinEnergy; }
  
  G4double elog = std::log10(6.7*kinEnergy/GeV);
  G4double aa = A;
 
  // from G4ProtonInelasticCrossSection
  G4double ff1 = 0.70 - 0.002*aa;           // slope of the drop at medium energies.
  G4double ff2 = 1.00 + 1/aa;               // start of the slope.
  G4double ff3 = 0.8  + 18/aa - 0.002*aa;   // stephight
  res = 1.0 + ff3*(1.0 - (1.0/(1+std::exp(-8*ff1*(elog + 1.37*ff2)))));
 
  ff1 = 1.   - 1./aa - 0.001*aa; // slope of the rise
  ff2 = 1.17 - 2.7/aa-0.0014*aa; // start of the rise
  res /= (1 + std::exp(-8.*ff1*(elog + 2*ff2)));
    /*
  G4double f1 = 8.0  - 8.0/aa - 0.008*aa;
  G4double f2 = 2.34 - 5.4/aa - 0.0028*aa;
 
  res = 1.0/(1.0 + std::exp(-f1*(elog + f2)));
 
  f1 = 5.6 - 0.016*aa;
  f2 = 1.37 + 1.37/aa;
  res *= ( 1.0 + (0.8 + 18./aa - 0.002*aa)/(1.0 + std::exp(f1*(elog + f2))));
    */
  return res;  
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
 
void
G4BGGPionInelasticXS::CrossSectionDescription(std::ostream& outFile) const 
{
  outFile << "The Barashenkov-Glauber-Gribov cross section handles inelastic\n"
          << "pion scattering from nuclei at all energies.  The Barashenkov\n"
          << "parameterization is used below 91 GeV and the Glauber-Gribov\n"
          << "parameterization is used above 91 GeV.\n";
}
 
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......