Gabriele Cosmo
167 lines
6.2 KiB
C++
167 lines
6.2 KiB
C++
//
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// ********************************************************************
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// * License and Disclaimer *
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// * *
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// * The Geant4 software is copyright of the Copyright Holders of *
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// * the Geant4 Collaboration. It is provided under the terms and *
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// * conditions of the Geant4 Software License, included in the file *
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// * LICENSE and available at http://cern.ch/geant4/license . These *
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// * include a list of copyright holders. *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. Please see the license in the file LICENSE and URL above *
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// * for the full disclaimer and the limitation of liability. *
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// * *
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// * This code implementation is the result of the scientific and *
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// * technical work of the GEANT4 collaboration. *
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// * By using, copying, modifying or distributing the software (or *
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// * any work based on the software) you agree to acknowledge its *
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// * use in resulting scientific publications, and indicate your *
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// * acceptance of all terms of the Geant4 Software license. *
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// ********************************************************************
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//
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// 18-Sep-2003 First version is written by T. Koi
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// 12-Nov-2003 Add energy check at lower side T. Koi
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// 15-Nov-2006 Above 10GeV/n Cross Section become constant T. Koi (SLAC/SCCS)
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// 23-Dec-2006 Isotope dependence adde by D. Wright
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// 14-Mar-2011 Moved constructor, destructor and virtual methods to source by V.Ivanchenko
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// 19-Aug-2011 V.Ivanchenko move to new design and make x-section per element
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//
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#include "G4IonsShenCrossSection.hh"
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#include "G4PhysicalConstants.hh"
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#include "G4SystemOfUnits.hh"
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#include "G4DynamicParticle.hh"
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#include "G4NucleiProperties.hh"
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#include "G4HadTmpUtil.hh"
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#include "G4NistManager.hh"
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G4IonsShenCrossSection::G4IonsShenCrossSection()
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: G4VCrossSectionDataSet("IonsShen"),
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upperLimit( 10*GeV ),
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// lowerLimit( 10*MeV ),
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r0 ( 1.1 )
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{}
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G4IonsShenCrossSection::~G4IonsShenCrossSection()
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{}
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void
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G4IonsShenCrossSection::CrossSectionDescription(std::ostream& outFile) const
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{
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outFile << "G4IonsShenCrossSection calculates the total reaction cross\n"
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<< "section for nucleus-nucleus scattering using the Shen\n"
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<< "parameterization. It is valid for projectiles and targets of\n"
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<< "all Z, and projectile energies up to 1 TeV/n. Above 10 GeV/n"
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<< "the cross section is constant. Below 10 MeV/n zero cross\n"
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<< "is returned.\n";
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}
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G4bool G4IonsShenCrossSection::IsElementApplicable(const G4DynamicParticle* aDP,
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G4int, const G4Material*)
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{
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return (1 <= aDP->GetDefinition()->GetBaryonNumber());
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}
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G4double
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G4IonsShenCrossSection::GetElementCrossSection(const G4DynamicParticle* aParticle,
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G4int Z,
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const G4Material*)
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{
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G4int A = G4lrint(G4NistManager::Instance()->GetAtomicMassAmu(Z));
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return GetIsoCrossSection(aParticle, Z, A);
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}
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G4double G4IonsShenCrossSection::GetIsoCrossSection(const G4DynamicParticle* aParticle,
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G4int Zt, G4int At,
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const G4Isotope*,
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const G4Element*,
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const G4Material*)
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{
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G4double xsection = 0.0;
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G4int Ap = aParticle->GetDefinition()->GetBaryonNumber();
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G4int Zp = G4lrint(aParticle->GetDefinition()->GetPDGCharge()/eplus);
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G4double ke_per_N = aParticle->GetKineticEnergy() / Ap;
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if ( ke_per_N > upperLimit ) { ke_per_N = upperLimit; }
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// Apply energy check, if less than lower limit then 0 value is returned
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//if ( ke_per_N < lowerLimit ) { return xsection; }
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G4Pow* g4pow = G4Pow::GetInstance();
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G4double cubicrAt = g4pow->Z13(At);
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G4double cubicrAp = g4pow->Z13(Ap);
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G4double Rt = 1.12 * cubicrAt - 0.94 * ( 1.0 / cubicrAt );
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G4double Rp = 1.12 * cubicrAp - 0.94 * ( 1.0 / cubicrAp );
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G4double r = Rt + Rp + 3.2; // in fm
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G4double b = 1.0; // in MeV/fm
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G4double targ_mass = G4NucleiProperties::GetNuclearMass(At, Zt);
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G4double proj_mass = aParticle->GetMass();
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G4double proj_momentum = aParticle->GetMomentum().mag();
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G4double Ecm = calEcmValue (proj_mass, targ_mass, proj_momentum);
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G4double B = 1.44 * Zt * Zp / r - b * Rt * Rp / ( Rt + Rp );
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if(Ecm <= B) { return xsection; }
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G4double c = calCeValue ( ke_per_N / MeV );
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G4double R1 = r0 * (cubicrAt + cubicrAp + 1.85*cubicrAt*cubicrAp/(cubicrAt + cubicrAp) - c);
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G4double R2 = 1.0 * ( At - 2 * Zt ) * Zp / ( Ap * At );
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G4double R3 = (0.176 / g4pow->A13(Ecm)) * cubicrAt * cubicrAp /(cubicrAt + cubicrAp);
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G4double R = R1 + R2 + R3;
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xsection = 10 * pi * R * R * ( 1 - B / Ecm );
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xsection = xsection * millibarn; // mulitply xsection by millibarn
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return xsection;
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}
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G4double
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G4IonsShenCrossSection::calEcmValue(const G4double mp, const G4double mt,
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const G4double Plab)
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{
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G4double Elab = std::sqrt ( mp * mp + Plab * Plab );
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G4double Ecm = std::sqrt ( mp * mp + mt * mt + 2 * Elab * mt );
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G4double Pcm = Plab * mt / Ecm;
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G4double KEcm = std::sqrt ( Pcm * Pcm + mp * mp ) - mp;
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return KEcm;
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}
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G4double G4IonsShenCrossSection::calCeValue(const G4double ke)
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{
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// Calculate c value
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// This value is indepenent from projectile and target particle
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// ke is projectile kinetic energy per nucleon in the Lab system
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// with MeV unit
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// fitting function is made by T. Koi
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// There are no data below 30 MeV/n in Kox et al.,
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G4double Ce;
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G4double log10_ke = std::log10 ( ke );
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if (log10_ke > 1.5)
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{
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Ce = -10.0/std::pow(G4double(log10_ke), G4double(5)) + 2.0;
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}
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else
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{
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Ce = (-10.0/std::pow(G4double(1.5), G4double(5) ) + 2.0) /
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std::pow(G4double(1.5) , G4double(3)) * std::pow(G4double(log10_ke), G4double(3));
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}
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return Ce;
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}
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