G4PreCompoundFragment.cc

Go to the documentation of this file.
00001 //
00002 // ********************************************************************
00003 // * License and Disclaimer                                           *
00004 // *                                                                  *
00005 // * The  Geant4 software  is  copyright of the Copyright Holders  of *
00006 // * the Geant4 Collaboration.  It is provided  under  the terms  and *
00007 // * conditions of the Geant4 Software License,  included in the file *
00008 // * LICENSE and available at  http://cern.ch/geant4/license .  These *
00009 // * include a list of copyright holders.                             *
00010 // *                                                                  *
00011 // * Neither the authors of this software system, nor their employing *
00012 // * institutes,nor the agencies providing financial support for this *
00013 // * work  make  any representation or  warranty, express or implied, *
00014 // * regarding  this  software system or assume any liability for its *
00015 // * use.  Please see the license in the file  LICENSE  and URL above *
00016 // * for the full disclaimer and the limitation of liability.         *
00017 // *                                                                  *
00018 // * This  code  implementation is the result of  the  scientific and *
00019 // * technical work of the GEANT4 collaboration.                      *
00020 // * By using,  copying,  modifying or  distributing the software (or *
00021 // * any work based  on the software)  you  agree  to acknowledge its *
00022 // * use  in  resulting  scientific  publications,  and indicate your *
00023 // * acceptance of all terms of the Geant4 Software license.          *
00024 // ********************************************************************
00025 //
00026 // $Id$
00027 //
00028 // J. M. Quesada (August 2008).  
00029 // Based  on previous work by V. Lara
00030 //
00031 // Modified:
00032 // 06.09.2008 JMQ Also external choice has been added for:
00033 //               - superimposed Coulomb barrier (if useSICB=true) 
00034 // 20.08.2010 V.Ivanchenko cleanup
00035 //
00036 
00037 #include "G4PreCompoundFragment.hh"
00038 
00039 G4PreCompoundFragment::
00040 G4PreCompoundFragment(const G4ParticleDefinition* part,
00041                       G4VCoulombBarrier* aCoulombBarrier)
00042   : G4VPreCompoundFragment(part,aCoulombBarrier)
00043 {}
00044 
00045 G4PreCompoundFragment::~G4PreCompoundFragment()
00046 {}
00047 
00048 G4double G4PreCompoundFragment::
00049 CalcEmissionProbability(const G4Fragment & aFragment)
00050 {
00051   //G4cout << theCoulombBarrier << "  " << GetMaximalKineticEnergy() << G4endl;
00052   // If  theCoulombBarrier effect is included in the emission probabilities
00053   //if (GetMaximalKineticEnergy() <= 0.0) 
00054   G4double limit = 0.0;
00055   if(OPTxs==0 ||  useSICB) { limit = theCoulombBarrier; }
00056   if (GetMaximalKineticEnergy() <= limit) 
00057     {
00058       theEmissionProbability = 0.0;
00059       return 0.0;
00060     }    
00061   // If  theCoulombBarrier effect is included in the emission probabilities
00062   //  G4double LowerLimit = 0.;
00063   // Coulomb barrier is the lower limit 
00064   // of integration over kinetic energy
00065   G4double LowerLimit = limit;
00066 
00067   // Excitation energy of nucleus after fragment emission is the upper 
00068   //limit of integration over kinetic energy
00069   G4double UpperLimit = GetMaximalKineticEnergy();
00070   
00071   theEmissionProbability = 
00072     IntegrateEmissionProbability(LowerLimit,UpperLimit,aFragment);
00073   /*
00074   G4cout << "## G4PreCompoundFragment::CalcEmisProb "
00075          << "Z= " << aFragment.GetZ_asInt() 
00076          << " A= " << aFragment.GetA_asInt()
00077          << " Elow= " << LowerLimit/MeV
00078          << " Eup= " << UpperLimit/MeV
00079          << " prob= " << theEmissionProbability
00080          << G4endl;
00081   */
00082   return theEmissionProbability;
00083 }
00084 
00085 G4double G4PreCompoundFragment::
00086 IntegrateEmissionProbability(G4double Low, G4double Up,
00087                              const G4Fragment & aFragment)
00088 {
00089   static const G4int N = 10;
00090   // 10-Points Gauss-Legendre abcisas and weights
00091   static const G4double w[N] = {
00092     0.0666713443086881,
00093     0.149451349150581,
00094     0.219086362515982,
00095     0.269266719309996,
00096     0.295524224714753,
00097     0.295524224714753,
00098     0.269266719309996,
00099     0.219086362515982,
00100     0.149451349150581,
00101     0.0666713443086881
00102   };
00103   static const G4double x[N] = {
00104     -0.973906528517172,
00105     -0.865063366688985,
00106     -0.679409568299024,
00107     -0.433395394129247,
00108     -0.148874338981631,
00109     0.148874338981631,
00110     0.433395394129247,
00111     0.679409568299024,
00112     0.865063366688985,
00113     0.973906528517172
00114   };
00115   
00116   G4double Total = 0.0;
00117 
00118   for (G4int i = 0; i < N; ++i) 
00119     {
00120       G4double KineticE = 0.5*((Up-Low)*x[i]+(Up+Low));
00121       Total += w[i]*ProbabilityDistributionFunction(KineticE, aFragment);
00122     }
00123   Total  *= 0.5*(Up-Low);
00124   return Total;
00125 }
00126 
00127 G4double G4PreCompoundFragment::
00128 GetKineticEnergy(const G4Fragment & aFragment) 
00129 {
00130   //let's keep this way for consistency with CalcEmissionProbability method
00131   G4double V = 0.0;
00132   if(OPTxs==0 || useSICB) { V = theCoulombBarrier; }
00133 
00134   G4double Tmax = GetMaximalKineticEnergy();  
00135   if(Tmax < V) { return 0.0; }
00136   G4double T(0.0);
00137   G4double Probability(1.0);
00138   G4double maxProbability = GetEmissionProbability();
00139   do 
00140     {
00141       T = V + G4UniformRand()*(Tmax-V);
00142       Probability = ProbabilityDistributionFunction(T,aFragment);      
00143     }   while (maxProbability*G4UniformRand() > Probability);  
00144   return T;
00145 }

Generated on Mon May 27 17:49:24 2013 for Geant4 by  doxygen 1.4.7