G4CoulombBarrier.cc

Go to the documentation of this file.

//
// ********************************************************************
// * License and Disclaimer                                           *
// *                                                                  *
// * The  Geant4 software  is  copyright of the Copyright Holders  of *
// * the Geant4 Collaboration.  It is provided  under  the terms  and *
// * conditions of the Geant4 Software License,  included in the file *
// * LICENSE and available at  http://cern.ch/geant4/license .  These *
// * include a list of copyright holders.                             *
// *                                                                  *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work  make  any representation or  warranty, express or implied, *
// * regarding  this  software system or assume any liability for its *
// * use.  Please see the license in the file  LICENSE  and URL above *
// * for the full disclaimer and the limitation of liability.         *
// *                                                                  *
// * This  code  implementation is the result of  the  scientific and *
// * technical work of the GEANT4 collaboration.                      *
// * By using,  copying,  modifying or  distributing the software (or *
// * any work based  on the software)  you  agree  to acknowledge its *
// * use  in  resulting  scientific  publications,  and indicate your *
// * acceptance of all terms of the Geant4 Software license.          *
// ********************************************************************
//
// $Id: G4CoulombBarrier.cc 91834 2015-08-07 07:24:22Z gcosmo $
//
// Hadronic Process: Nuclear De-excitations
// by V. Lara (Dec 1999)
//
// 14-11-2007 modified barrier by JMQ (test30) 
// 15-11-2010 V.Ivanchenko use G4Pow and cleanup 

#include <sstream>

#include "G4CoulombBarrier.hh"
#include "G4PhysicalConstants.hh"
#include "G4SystemOfUnits.hh"
#include "G4HadronicException.hh"
#include "G4Pow.hh"

G4CoulombBarrier::G4CoulombBarrier(): G4VCoulombBarrier(1,0) 
{}

G4CoulombBarrier::G4CoulombBarrier(G4int anA, G4int aZ)
  : G4VCoulombBarrier(anA,aZ) 
{}

G4CoulombBarrier::~G4CoulombBarrier() 
{}

G4double G4CoulombBarrier::BarrierPenetrationFactor(G4double ) const 
{
  return 1.0;
}

G4double G4CoulombBarrier::GetCoulombBarrier(const G4int ARes, 
                                             const G4int ZRes, const G4double) const 
  // Calculation of Coulomb potential energy (barrier) for outgoing fragment
{
  G4double Barrier = 0.0;
  if (GetA() == 1 && GetZ() == 0) {
    Barrier = 0.0;   // Neutron Coulomb Barrier is 0
  } else {

    // JMQ: old coulomb barrier commented since it does not agree with 
    //      Dostrovski's prescription
    //      and too low  barriers are obtained (for protons at least)

    G4double rho=1.2*fermi; 
    if(GetA()==1 && GetZ()==1){  rho=0.0;}  

    const G4double RN=1.5*fermi;  
    // VI cleanup 
    Barrier=elm_coupling*(GetZ()*ZRes)/(RN * G4Pow::GetInstance()->Z13(ARes) + rho);

    // Barrier penetration coeficient
    G4double K = BarrierPenetrationFactor(ZRes);

    Barrier *= K;
                
    // JMQ : the following statement has unknown origin and dimensionally 
    //  is meaningless( energy divided by mass number in argument of sqrt function). 
    //  Energy dependence of Coulomb barrier penetrability should be included in 
    //  proper way (if needed..)
    //   Barrier /= (1.0 + std::sqrt(U/(2.0*static_cast<G4double>(ARes))));
    //
  }
  return Barrier;
}