G4StatMFMicroManager.cc

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//
//
// Hadronic Process: Nuclear De-excitations
// by V. Lara
 
#include "G4StatMFMicroManager.hh"
#include "G4HadronicException.hh"
 
// constructor
G4StatMFMicroManager::G4StatMFMicroManager(const G4Fragment & theFragment, 
                       G4int multiplicity,
                       G4double FreeIntE, G4double SCompNuc) : 
  _Normalization(0.0)
{
  // Perform class initialization
  Initialize(theFragment,multiplicity,FreeIntE,SCompNuc);
}
 
// destructor
G4StatMFMicroManager::~G4StatMFMicroManager() 
{
  if (!_Partition.empty()) {
    for (auto & p : _Partition) { delete p; }
  }
}
 
void G4StatMFMicroManager::Initialize(const G4Fragment & theFragment, G4int im, 
                      G4double FreeIntE, G4double SCompNuc) 
{
  G4int i;
 
  G4double U = theFragment.GetExcitationEnergy();
 
  G4int A = theFragment.GetA_asInt();
  G4int Z = theFragment.GetZ_asInt();
    
  // Statistical weights
  _WW = 0.0;
 
  // Mean breakup multiplicity
  _MeanMultiplicity = 0.0;
 
  // Mean channel temperature
  _MeanTemperature = 0.0;
 
  // Mean channel entropy
  _MeanEntropy = 0.0;   
    
  // Keep fragment atomic numbers
  //    G4int * FragmentAtomicNumbers = new G4int(static_cast<G4int>(A+0.5));
  //    G4int * FragmentAtomicNumbers = new G4int(m);
  G4int FragmentAtomicNumbers[4];
    
  // We distribute A nucleons between m fragments mantaining the order
  // FragmentAtomicNumbers[m-1]>FragmentAtomicNumbers[m-2]>...>FragmentAtomicNumbers[0]
  // Our initial distribution is 
  // FragmentAtomicNumbers[m-1]=A, FragmentAtomicNumbers[m-2]=0, ..., FragmentAtomicNumbers[0]=0
  FragmentAtomicNumbers[im-1] = A;
  for (i = 0; i <  (im - 1); i++) FragmentAtomicNumbers[i] = 0;
 
  // We try to distribute A nucleons in partitions of m fragments
  // MakePartition return true if it is possible 
  // and false if it is not 
 
  // Loop checking, 05-Aug-2015, Vladimir Ivanchenko
  while (MakePartition(im,FragmentAtomicNumbers)) {
    // Allowed partitions are stored and its probability calculated
            
    G4StatMFMicroPartition * aPartition = new G4StatMFMicroPartition(A,Z);
    G4double PartitionProbability = 0.0;
            
    for (i = im-1; i >= 0; i--) aPartition->SetPartitionFragment(FragmentAtomicNumbers[i]);
    PartitionProbability = aPartition->CalcPartitionProbability(U,FreeIntE,SCompNuc);
    _Partition.push_back(aPartition);
            
    _WW += PartitionProbability;
    _MeanMultiplicity += im*PartitionProbability;
    _MeanTemperature += aPartition->GetTemperature() * PartitionProbability;
    if (PartitionProbability > 0.0) 
      _MeanEntropy += PartitionProbability * aPartition->GetEntropy();
  }
}
 
G4bool G4StatMFMicroManager::MakePartition(G4int k, G4int * ANumbers)
// Distributes A nucleons between k fragments
// mantaining the order ANumbers[k-1] > ANumbers[k-2] > ... > ANumbers[0]
// If it is possible returns true. In other case returns false
{
  G4int l = 1;
  // Loop checking, 05-Aug-2015, Vladimir Ivanchenko
  while (l < k) {
    G4int tmp = ANumbers[l-1] + ANumbers[k-1];
    ANumbers[l-1] += 1;
    ANumbers[k-1] -= 1;
    if (ANumbers[l-1] > ANumbers[l] || ANumbers[k-2] > ANumbers[k-1]) {
      ANumbers[l-1] = 1;
      ANumbers[k-1] = tmp - 1;
      l++;
    } else return true;
  }
  return false;
}
 
void G4StatMFMicroManager::Normalize(G4double Norm)
{
  _Normalization = Norm;
  _WW /= Norm;
  _MeanMultiplicity /= Norm;
  _MeanTemperature /= Norm;
  _MeanEntropy /= Norm; 
    
  return;
}
 
G4StatMFChannel* 
G4StatMFMicroManager::ChooseChannel(G4int A0, G4int Z0, G4double MeanT)
{
  G4double RandNumber = _Normalization * _WW * G4UniformRand();
  G4double AccumWeight = 0.0;
    
  for (auto & p : _Partition) {
    AccumWeight += p->GetProbability();
    if (RandNumber <= AccumWeight)
      return p->ChooseZ(A0,Z0,MeanT);
  }
 
  throw G4HadronicException(__FILE__, __LINE__, 
                "G4StatMFMicroManager::ChooseChannel: Couldn't find a channel.");
  return nullptr;
}