| 1 | //
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| 2 | // ********************************************************************
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| 3 | // * License and Disclaimer *
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| 4 | // * *
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| 5 | // * The Geant4 software is copyright of the Copyright Holders of *
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| 6 | // * the Geant4 Collaboration. It is provided under the terms and *
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| 7 | // * conditions of the Geant4 Software License, included in the file *
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| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These *
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| 9 | // * include a list of copyright holders. *
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| 10 | // * *
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| 11 | // * Neither the authors of this software system, nor their employing *
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| 12 | // * institutes,nor the agencies providing financial support for this *
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| 13 | // * work make any representation or warranty, express or implied, *
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| 14 | // * regarding this software system or assume any liability for its *
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| 15 | // * use. Please see the license in the file LICENSE and URL above *
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| 16 | // * for the full disclaimer and the limitation of liability. *
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| 17 | // * *
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| 18 | // * This code implementation is the result of the scientific and *
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| 19 | // * technical work of the GEANT4 collaboration. *
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| 20 | // * By using, copying, modifying or distributing the software (or *
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| 21 | // * any work based on the software) you agree to acknowledge its *
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| 22 | // * use in resulting scientific publications, and indicate your *
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| 23 | // * acceptance of all terms of the Geant4 Software license. *
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| 24 | // ********************************************************************
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| 25 | //
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| 26 | // By JPW, working, but to be cleaned up. @@@
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| 27 | // 22 Dec 2006 - DHW added isotope dependence
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| 28 | //
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| 29 |
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| 30 | #include "G4NeutronInelasticCrossSection.hh"
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| 31 | #include "globals.hh"
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| 32 |
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| 33 | G4double G4NeutronInelasticCrossSection::
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| 34 | GetCrossSection(const G4DynamicParticle* aPart,
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| 35 | const G4Element* anEle, G4double /*aTemperature*/)
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| 36 | {
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| 37 | G4int nIso = anEle->GetNumberOfIsotopes();
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| 38 | G4double KE = aPart->GetKineticEnergy();
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| 39 | G4double cross_section = 0;
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| 40 |
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| 41 | if (nIso) {
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| 42 | G4double psig;
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| 43 | G4IsotopeVector* isoVector = anEle->GetIsotopeVector();
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| 44 | G4double* abundVector = anEle->GetRelativeAbundanceVector();
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| 45 | G4double ZZ;
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| 46 | G4double AA;
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| 47 |
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| 48 | for (G4int i = 0; i < nIso; i++) {
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| 49 | ZZ = G4double( (*isoVector)[i]->GetZ() );
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| 50 | AA = G4double( (*isoVector)[i]->GetN() );
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| 51 | psig = GetCrossSection(KE, AA, ZZ);
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| 52 | cross_section += psig*abundVector[i];
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| 53 | }
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| 54 |
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| 55 | } else {
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| 56 | cross_section = GetCrossSection(KE, anEle->GetN(), anEle->GetZ());
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| 57 | }
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| 58 |
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| 59 | return cross_section;
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| 60 | }
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| 61 |
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| 62 |
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| 63 | G4double G4NeutronInelasticCrossSection::
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| 64 | GetCrossSection(G4double anEnergy, G4double atomicNumber, G4double nOfProtons)
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| 65 | {
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| 66 | G4double kineticEnergy = std::log10(DBL_MIN/MeV);
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| 67 | if (anEnergy > DBL_MIN/MeV) kineticEnergy = std::log10(anEnergy/MeV);
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| 68 | G4double nOfNeutrons = atomicNumber-nOfProtons;
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| 69 | const G4double p1=1.3773;
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| 70 | const G4double p2=1.+10./atomicNumber-0.0006*atomicNumber;
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| 71 | const G4double p3=0.6+13./atomicNumber-0.0005*atomicNumber;
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| 72 | const G4double p4=7.2449-0.018242*atomicNumber;
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| 73 | const G4double p5=1.64-1.8/atomicNumber-0.0005*atomicNumber;
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| 74 | const G4double p6=1.+200./atomicNumber+0.02*atomicNumber;
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| 75 | const G4double p7=(atomicNumber-70.)*(atomicNumber-200.)/11000.;
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| 76 |
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| 77 | G4double logN = 1.0;
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| 78 | if (nOfNeutrons > 1.5) logN = std::log(nOfNeutrons);
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| 79 | G4double part1 = pi*(p1*p1)*logN;
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| 80 | G4double part2 = 1.+ std::pow(atomicNumber, 1./3.)
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| 81 | - p2*(1.-1./std::pow(atomicNumber, 1./3.));
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| 82 |
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| 83 | G4double firstexp = -p4*(kineticEnergy-p5);
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| 84 | G4double first=1.+std::exp(firstexp);
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| 85 | G4double corr = 1.+p3*(1.-1./first);
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| 86 |
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| 87 | G4double secondexp = -p6*(kineticEnergy-p7);
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| 88 | G4double second=1.+std::exp(secondexp);
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| 89 | G4double corr2 =1./second;
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| 90 |
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| 91 | G4double xsec = corr*corr2*part1*part2*10.*millibarn;
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| 92 | return xsec;
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| 93 | }
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