Gabriele Cosmo
123 lines
4.4 KiB
C++
123 lines
4.4 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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//
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// $Id$
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//
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//
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// --------------------------------------------------------------
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// GEANT 4 class implementation file/ History:
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// 5 Oct. 2002, H.Kuirashige : Structure created based on object model
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// --------------------------------------------------------------
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#include "G4RToEConvForElectron.hh"
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#include "G4ParticleDefinition.hh"
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#include "G4ParticleTable.hh"
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#include "G4Material.hh"
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#include "G4PhysicsLogVector.hh"
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#include "G4ios.hh"
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#include "G4PhysicalConstants.hh"
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#include "G4SystemOfUnits.hh"
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G4RToEConvForElectron::G4RToEConvForElectron() : G4VRangeToEnergyConverter()
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{
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theParticle = G4ParticleTable::GetParticleTable()->FindParticle("e-");
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if (theParticle ==0) {
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#ifdef G4VERBOSE
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if (GetVerboseLevel()>0) {
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G4cout << " G4RToEConvForElectron::G4RToEConvForElectron() ";
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G4cout << " Electron is not defined !!" << G4endl;
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}
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#endif
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}
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}
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G4RToEConvForElectron::~G4RToEConvForElectron()
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{
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}
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// **********************************************************************
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// ************************* ComputeLoss ********************************
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// **********************************************************************
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G4double G4RToEConvForElectron::ComputeLoss(G4double AtomicNumber,
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G4double KineticEnergy) const
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{
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static G4double Z;
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static G4double taul, ionpot, ionpotlog;
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const G4double cbr1=0.02, cbr2=-5.7e-5, cbr3=1., cbr4=0.072;
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const G4double Tlow=10.*keV, Thigh=1.*GeV;
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static G4double bremfactor= 0.1 ;
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static G4double Mass= theParticle->GetPDGMass();
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// calculate dE/dx for electrons
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if( std::fabs(AtomicNumber-Z)>0.1 ) {
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Z = AtomicNumber;
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taul = Tlow/Mass;
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ionpot = 1.6e-5*MeV*std::exp(0.9*std::log(Z))/Mass;
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ionpotlog = std::log(ionpot);
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}
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G4double tau = KineticEnergy/Mass;
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G4double dEdx;
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if(tau<taul) {
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G4double t1 = taul+1.;
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G4double t2 = taul+2.;
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G4double tsq = taul*taul;
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G4double beta2 = taul*t2/(t1*t1);
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G4double f = 1.-beta2+std::log(tsq/2.)
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+(0.5+0.25*tsq+(1.+2.*taul)*std::log(0.5))/(t1*t1);
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dEdx = (std::log(2.*taul+4.)-2.*ionpotlog+f)/beta2;
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dEdx = twopi_mc2_rcl2*Z*dEdx;
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G4double clow = dEdx*std::sqrt(taul);
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dEdx = clow/std::sqrt(KineticEnergy/Mass);
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} else {
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G4double t1 = tau+1.;
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G4double t2 = tau+2.;
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G4double tsq = tau*tau;
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G4double beta2 = tau*t2/(t1*t1);
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G4double f = 1.-beta2+std::log(tsq/2.)
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+(0.5+0.25*tsq+(1.+2.*tau)*std::log(0.5))/(t1*t1);
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dEdx = (std::log(2.*tau+4.)-2.*ionpotlog+f)/beta2;
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dEdx = twopi_mc2_rcl2*Z*dEdx;
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// loss from bremsstrahlung follows
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G4double cbrem = (cbr1+cbr2*Z)
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*(cbr3+cbr4*std::log(KineticEnergy/Thigh));
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cbrem = Z*(Z+1.)*cbrem*tau/beta2;
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cbrem *= bremfactor ;
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dEdx += twopi_mc2_rcl2*cbrem;
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}
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return dEdx;
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}
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