G4ParticleHPElasticData.cc

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//
// neutron_hp -- source file
// J.P. Wellisch, Nov-1996
// A prototype of the low energy neutron transport model.
//
// 070523 add neglecting doppler broadening on the fly. T. Koi
// 070613 fix memory leaking by T. Koi
// 071002 enable cross section dump by T. Koi
// 080428 change checking point of "neglecting doppler broadening" flag
//        from GetCrossSection to BuildPhysicsTable by T. Koi
// 081024 G4NucleiPropertiesTable:: to G4NucleiProperties::
//
// P. Arce, June-2014 Conversion neutron_hp to particle_hp
//
#include "G4ParticleHPElasticData.hh"
 
#include "G4Electron.hh"
#include "G4ElementTable.hh"
#include "G4HadronicParameters.hh"
#include "G4Neutron.hh"
#include "G4NucleiProperties.hh"
#include "G4Nucleus.hh"
#include "G4ParticleHPData.hh"
#include "G4ParticleHPManager.hh"
#include "G4PhysicalConstants.hh"
#include "G4Pow.hh"
#include "G4SystemOfUnits.hh"
 
G4ParticleHPElasticData::G4ParticleHPElasticData() : G4VCrossSectionDataSet("NeutronHPElasticXS")
{
  SetMinKinEnergy(0 * MeV);
  SetMaxKinEnergy(20 * MeV);
 
  theCrossSections = nullptr;
  instanceOfWorker = false;
  if (G4Threading::IsWorkerThread()) {
    instanceOfWorker = true;
  }
  element_cache = nullptr;
  material_cache = nullptr;
  ke_cache = 0.0;
  xs_cache = 0.0;
  // BuildPhysicsTable( *G4Neutron::Neutron() );
}
 
G4ParticleHPElasticData::~G4ParticleHPElasticData()
{
  if (theCrossSections != nullptr && !instanceOfWorker) {
    theCrossSections->clearAndDestroy();
    delete theCrossSections;
    theCrossSections = nullptr;
  }
}
 
G4bool G4ParticleHPElasticData::IsIsoApplicable(const G4DynamicParticle* dp, G4int /*Z*/,
                                                G4int /*A*/, const G4Element* /*elm*/,
                                                const G4Material* /*mat*/)
{
  G4double eKin = dp->GetKineticEnergy();
  return eKin <= GetMaxKinEnergy() && eKin >= GetMinKinEnergy()
         && dp->GetDefinition() == G4Neutron::Neutron();
}
 
G4double G4ParticleHPElasticData::GetIsoCrossSection(const G4DynamicParticle* dp, G4int /*Z*/,
                                                     G4int /*A*/, const G4Isotope* /*iso*/,
                                                     const G4Element* element,
                                                     const G4Material* material)
{
  if (dp->GetKineticEnergy() == ke_cache && element == element_cache && material == material_cache)
    return xs_cache;
 
  ke_cache = dp->GetKineticEnergy();
  element_cache = element;
  material_cache = material;
  G4double xs = GetCrossSection(dp, element, material->GetTemperature());
  xs_cache = xs;
  return xs;
}
 
void G4ParticleHPElasticData::BuildPhysicsTable(const G4ParticleDefinition& aP)
{
  if (&aP != G4Neutron::Neutron())
    throw G4HadronicException(__FILE__, __LINE__,
                              "Attempt to use NeutronHP data for particles other than neutrons!!!");
 
  if (G4Threading::IsWorkerThread()) {
    theCrossSections = G4ParticleHPManager::GetInstance()->GetElasticCrossSections();
    return;
  }
 
  std::size_t numberOfElements = G4Element::GetNumberOfElements();
  // TKDB
  // if ( theCrossSections == 0 ) theCrossSections = new G4PhysicsTable( numberOfElements );
  if (theCrossSections == nullptr)
    theCrossSections = new G4PhysicsTable(numberOfElements);
  else
    theCrossSections->clearAndDestroy();
 
  // make a PhysicsVector for each element
 
  auto theElementTable = G4Element::GetElementTable();
  for (std::size_t i = 0; i < numberOfElements; ++i) {
    G4PhysicsVector* physVec = G4ParticleHPData::Instance(G4Neutron::Neutron())
                                 ->MakePhysicsVector((*theElementTable)[i], this);
    theCrossSections->push_back(physVec);
  }
 
  G4ParticleHPManager::GetInstance()->RegisterElasticCrossSections(theCrossSections);
}
 
void G4ParticleHPElasticData::DumpPhysicsTable(const G4ParticleDefinition&)
{
#ifdef G4VERBOSE
  if (G4HadronicParameters::Instance()->GetVerboseLevel() == 0) return;
 
  //
  // Dump element based cross section
  // range 10e-5 eV to 20 MeV
  // 10 point per decade
  // in barn
  //
 
  G4cout << G4endl;
  G4cout << G4endl;
  G4cout << "Elastic Cross Section of Neutron HP" << G4endl;
  G4cout << "(Pointwise cross-section at 0 Kelvin.)" << G4endl;
  G4cout << G4endl;
  G4cout << "Name of Element" << G4endl;
  G4cout << "Energy[eV]  XS[barn]" << G4endl;
  G4cout << G4endl;
 
  std::size_t numberOfElements = G4Element::GetNumberOfElements();
  auto theElementTable = G4Element::GetElementTable();
 
  for (std::size_t i = 0; i < numberOfElements; ++i) {
    G4cout << (*theElementTable)[i]->GetName() << G4endl;
    G4int ie = 0;
 
    for (ie = 0; ie < 130; ++ie) {
      G4double eKinetic = 1.0e-5 * G4Pow::GetInstance()->powA(10.0, ie / 10.0) * eV;
      G4bool outOfRange = false;
 
      if (eKinetic < 20 * MeV) {
        G4cout << eKinetic / eV << " "
               << (*((*theCrossSections)(i))).GetValue(eKinetic, outOfRange) / barn << G4endl;
      }
    }
    G4cout << G4endl;
  }
#endif
}
 
G4double G4ParticleHPElasticData::GetCrossSection(const G4DynamicParticle* aP, const G4Element* anE,
                                                  G4double aT)
{
  G4double result = 0;
  G4bool outOfRange;
  auto index = (G4int)anE->GetIndex();
 
  // prepare neutron
  G4double eKinetic = aP->GetKineticEnergy();
 
  if (G4ParticleHPManager::GetInstance()->GetNeglectDoppler()) {
    // NEGLECT_DOPPLER_B.
    G4double factor = 1.0;
    if (eKinetic < aT * k_Boltzmann) {
      // below 0.1 eV neutrons
      // Have to do some, but now just igonre.
      // Will take care after performance check.
      // factor = factor * targetV;
    }
    return ((*((*theCrossSections)(index))).GetValue(eKinetic, outOfRange)) * factor;
  }
 
  G4ReactionProduct theNeutron(aP->GetDefinition());
  theNeutron.SetMomentum(aP->GetMomentum());
  theNeutron.SetKineticEnergy(eKinetic);
 
  // prepare thermal nucleus
  G4Nucleus aNuc;
  G4double eps = 0.0001;
  G4double theA = anE->GetN();
  G4double theZ = anE->GetZ();
  G4double eleMass;
 
  eleMass = (G4NucleiProperties::GetNuclearMass(G4int(theA + eps), G4int(theZ + eps)))
            / G4Neutron::Neutron()->GetPDGMass();
 
  G4ReactionProduct boosted;
  G4double aXsection;
 
  // MC integration loop
  G4int counter = 0;
  G4double buffer = 0;
  G4int size = G4int(std::max(10., aT / 60 * kelvin));
  G4ThreeVector neutronVelocity =
    1. / G4Neutron::Neutron()->GetPDGMass() * theNeutron.GetMomentum();
  G4double neutronVMag = neutronVelocity.mag();
 
  while (counter == 0
         || std::abs(buffer - result / std::max(1, counter))
              > 0.03 * buffer)  // Loop checking, 11.05.2015, T. Koi
  {
    if (counter != 0) buffer = result / counter;
    while (counter < size)  // Loop checking, 11.05.2015, T. Koi
    {
      counter++;
      G4ReactionProduct aThermalNuc = aNuc.GetThermalNucleus(eleMass, aT);
      boosted.Lorentz(theNeutron, aThermalNuc);
      G4double theEkin = boosted.GetKineticEnergy();
      aXsection = (*((*theCrossSections)(index))).GetValue(theEkin, outOfRange);
      // velocity correction.
      G4ThreeVector targetVelocity = 1. / aThermalNuc.GetMass() * aThermalNuc.GetMomentum();
      aXsection *= (targetVelocity - neutronVelocity).mag() / neutronVMag;
      result += aXsection;
    }
    size += size;
  }
  result /= counter;
  /*
    // Checking impact of  G4NEUTRONHP_NEGLECT_DOPPLER
    G4cout << " result " << result << " "
           << (*((*theCrossSections)(index))).GetValue(eKinetic, outOfRange) << " "
           << (*((*theCrossSections)(index))).GetValue(eKinetic, outOfRange) /result << G4endl;
  */
  return result;
}
 
G4int G4ParticleHPElasticData::GetVerboseLevel() const
{
  return G4ParticleHPManager::GetInstance()->GetVerboseLevel();
}
 
void G4ParticleHPElasticData::SetVerboseLevel(G4int newValue)
{
  G4ParticleHPManager::GetInstance()->SetVerboseLevel(newValue);
}
 
void G4ParticleHPElasticData::CrossSectionDescription(std::ostream& outFile) const
{
  outFile << "High Precision cross data based on Evaluated Nuclear Data Files (ENDF) for elastic "
             "reaction of neutrons below 20MeV\n";
}