G4DNASmoluchowskiReactionModel.cc

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// $Id: G4DNASmoluchowskiReactionModel.cc 85244 2014-10-27 08:24:13Z gcosmo $
//
#include "G4DNASmoluchowskiReactionModel.hh"
#include "Randomize.hh"
#include "G4Track.hh"
#include "G4DNAMolecularReactionTable.hh"
#include "G4UnitsTable.hh"

G4DNASmoluchowskiReactionModel::G4DNASmoluchowskiReactionModel() :
    G4VDNAReactionModel()
{
  fReactionData = 0;
}

G4DNASmoluchowskiReactionModel::G4DNASmoluchowskiReactionModel(const G4DNASmoluchowskiReactionModel& __right) :
    G4VDNAReactionModel(__right)
{
  fReactionData = 0;
}

G4DNASmoluchowskiReactionModel& G4DNASmoluchowskiReactionModel::operator=(const G4DNASmoluchowskiReactionModel& right)
{
  if (this == &right) return *this;
  fReactionData = 0;
  return *this;
}

G4DNASmoluchowskiReactionModel::~G4DNASmoluchowskiReactionModel()
{
  fReactionData = 0;
}

void G4DNASmoluchowskiReactionModel::Initialise(const G4Molecule* __molecule,
                                                const G4Track&)
{
  fReactionData = fReactionTable->GetReactionData(__molecule);
}

void G4DNASmoluchowskiReactionModel::InitialiseToPrint(const G4Molecule* __molecule)
{
  fReactionData = fReactionTable->GetReactionData(__molecule);
}

G4double G4DNASmoluchowskiReactionModel::GetReactionRadius(const G4Molecule* mol1,
                                                           const G4Molecule* mol2)
{
  G4double __output = fReactionTable->GetReactionData(mol1, mol2)
      ->GetReducedReactionRadius();
  return __output;
}

G4double G4DNASmoluchowskiReactionModel::GetReactionRadius(const G4int __i)
{
  G4double __output = (*fReactionData)[__i]->GetReducedReactionRadius();
  return __output;
}

G4bool G4DNASmoluchowskiReactionModel::FindReaction(const G4Track& __trackA,
                                                    const G4Track& __trackB,
                                                    const G4double __R,
                                                    G4double& __r,
                                                    const G4bool __alongStepReaction)
{
  G4double __postStepSeparation = 0;
  bool __do_break = false;
  G4double __R2 = __R * __R;
  int k = 0;

  for (; k < 3; k++)
  {
    __postStepSeparation += std::pow(
        __trackA.GetPosition()[k] - __trackB.GetPosition()[k], 2);

    if (__postStepSeparation > __R2)
    {
      __do_break = true;
      break;
    }
  }

  if (__do_break == false)
  {
    // The loop was not break
    // => __r^2 < __R^2
    __r = std::sqrt(__postStepSeparation);
    return true;
  }
  else if (__alongStepReaction == true)
  {
    //G4cout << "alongStepReaction==true" << G4endl;
    //Along step cheack and
    // the loop has break

    // Continue loop
    for (; k < 3; k++)
    {
      __postStepSeparation += std::pow(
          __trackA.GetPosition()[k] - __trackB.GetPosition()[k], 2);
    }
    // Use Green approach : the Brownian bridge
    __r = (__postStepSeparation = std::sqrt(__postStepSeparation));

    G4Molecule* __moleculeA = GetMolecule(__trackA);
    G4Molecule* __moleculeB = GetMolecule(__trackB);

    G4double __D = __moleculeA->GetDiffusionCoefficient()
        + __moleculeB->GetDiffusionCoefficient();

    G4ThreeVector __preStepPositionA = __trackA.GetStep()->GetPreStepPoint()
        ->GetPosition();
    G4ThreeVector __preStepPositionB = __trackB.GetStep()->GetPreStepPoint()
        ->GetPosition();

    if (__preStepPositionA == __trackA.GetPosition())
    {
      G4ExceptionDescription exceptionDescription;
      exceptionDescription << "The molecule : " << __moleculeA->GetName();
      exceptionDescription << " with track ID :" << __trackA.GetTrackID();
      exceptionDescription << " did not move since the previous step." << G4endl;
      exceptionDescription << "Current position : "
                           << G4BestUnit(__trackA.GetPosition(), "Length")
                           << G4endl;
      exceptionDescription << "Previous position : "
                           << G4BestUnit(__preStepPositionA, "Length") << G4endl;
      G4Exception("G4DNASmoluchowskiReactionModel::FindReaction",
                  "G4DNASmoluchowskiReactionModel", FatalErrorInArgument,
                  exceptionDescription);
    }

    G4double __preStepSeparation =
        (__preStepPositionA - __preStepPositionB).mag();

    G4double __probabiltyOfEncounter = std::exp(
        -(__preStepSeparation - __R) * (__postStepSeparation - __R) / (__D
            * (__trackB.GetStep()->GetDeltaTime())));
    G4double __selectedPOE = G4UniformRand();

    if (__selectedPOE <= __probabiltyOfEncounter) return true;
  }

  return false;
}