source: trunk/source/processes/hadronic/models/de_excitation/fission/src/G4FissionParameters.cc @ 1007

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// $Id: G4FissionParameters.cc,v 1.5 2006/06/29 20:13:39 gunter Exp $
// GEANT4 tag $Name: geant4-09-02 $
//
// Hadronic Process: Nuclear De-excitations
// by V. Lara (Oct 1998)
//


#include "G4FissionParameters.hh"
#include "G4HadronicException.hh"


const G4double G4FissionParameters::A1 = 134.0;
const G4double G4FissionParameters::A2 = 141.0;


G4FissionParameters::G4FissionParameters(const G4int A, const G4int Z, const G4double ExEnergy,
                                         const G4double FissionBarrier)
{
    G4double U = ExEnergy; 
  
    As = A/2.0;

    if (A <= 235) Sigma2 = 5.6;  // MeV
    else Sigma2 = 5.6 + 0.096*(A-235); // MeV

    Sigma1 = 0.5*Sigma2; // MeV

    SigmaS = std::exp(0.00553*U/MeV + 2.1386); // MeV
    if (SigmaS > 20.0) SigmaS = 20.0;

    G4double FasymAsym = 2.0*std::exp(-((A2-As)*(A2-As))/(2.0*Sigma2*Sigma2)) + 
        std::exp(-((A1-As)*(A1-As))/(2.0*Sigma1*Sigma1));
  
    G4double FsymA1A2 = std::exp(-((As-(A1+A2)/2.0)*(As-(A1+A2)/2.0))/(2.0*SigmaS*SigmaS));
  

    G4double wa = 0.0;
    w = 0.0;
    if (Z >= 90) {         // Z >= 90
        if (U <= 16.25) wa = std::exp(0.5385*U/MeV-9.9564);  // U <= 16.25 MeV
        else wa = std::exp(0.09197*U/MeV-2.7003);            // U  > 16.25 MeV
    } else if (Z == 89) {  // Z == 89
        wa = std::exp(0.09197*U-1.0808);
    } else if (Z >= 82) {  //  82 <= Z <= 88
        G4double X = FissionBarrier - 7.5*MeV;
        if (X < 0.0) X = 0.0;
        wa = std::exp(0.09197*(U-X)/MeV-1.0808);
    } else {               // Z < 82
        w = 1001.0;
    }
  
    if (w == 0.0) {
        G4double w1 = std::max(1.03*wa - FasymAsym, 0.0001);
        G4double w2 = std::max(1.0 - FsymA1A2*wa,   0.0001);
    
        w = w1/w2;

        if (82 <= Z && Z < 89 && A < 227)  w *= std::exp(0.3*(227-A));
    }
  
}


G4FissionParameters::G4FissionParameters(const G4FissionParameters &)
{
    throw G4HadronicException(__FILE__, __LINE__, "G4FissionParameters::copy_constructor meant to not be accessable");
}


const G4FissionParameters & G4FissionParameters::operator=(const G4FissionParameters &)
{
    throw G4HadronicException(__FILE__, __LINE__, "G4FissionParameters::operator= meant to not be accessable");
    return *this;
}


G4bool G4FissionParameters::operator==(const G4FissionParameters &) const
{
    return false;
}

G4bool G4FissionParameters::operator!=(const G4FissionParameters &) const
{
    return true;
}