00001 // 00002 // ******************************************************************** 00003 // * License and Disclaimer * 00004 // * * 00005 // * The Geant4 software is copyright of the Copyright Holders of * 00006 // * the Geant4 Collaboration. It is provided under the terms and * 00007 // * conditions of the Geant4 Software License, included in the file * 00008 // * LICENSE and available at http://cern.ch/geant4/license . These * 00009 // * include a list of copyright holders. * 00010 // * * 00011 // * Neither the authors of this software system, nor their employing * 00012 // * institutes,nor the agencies providing financial support for this * 00013 // * work make any representation or warranty, express or implied, * 00014 // * regarding this software system or assume any liability for its * 00015 // * use. Please see the license in the file LICENSE and URL above * 00016 // * for the full disclaimer and the limitation of liability. * 00017 // * * 00018 // * This code implementation is the result of the scientific and * 00019 // * technical work of the GEANT4 collaboration. * 00020 // * By using, copying, modifying or distributing the software (or * 00021 // * any work based on the software) you agree to acknowledge its * 00022 // * use in resulting scientific publications, and indicate your * 00023 // * acceptance of all terms of the Geant4 Software license. * 00024 // ******************************************************************** 00025 // 00026 // 00027 // $Id$ 00028 // 00029 // 00030 // -------------------------------------------------------------- 00031 // GEANT 4 class implementation file/ History: 00032 // 5 Oct. 2002, H.Kuirashige : Structure created based on object model 00033 // -------------------------------------------------------------- 00034 00035 #include "G4RToEConvForProton.hh" 00036 #include "G4ParticleTable.hh" 00037 #include "G4Material.hh" 00038 #include "G4PhysicsLogVector.hh" 00039 00040 #include "G4ios.hh" 00041 #include "G4PhysicalConstants.hh" 00042 #include "G4SystemOfUnits.hh" 00043 00044 G4RToEConvForProton::G4RToEConvForProton() : G4VRangeToEnergyConverter() 00045 { 00046 theParticle = G4ParticleTable::GetParticleTable()->FindParticle("proton"); 00047 if (theParticle ==0) { 00048 #ifdef G4VERBOSE 00049 if (GetVerboseLevel()>0) { 00050 G4cout << " G4RToEConvForProton::G4RToEConvForProton() "; 00051 G4cout << " proton is not defined !!" << G4endl; 00052 } 00053 #endif 00054 } 00055 } 00056 00057 G4RToEConvForProton::~G4RToEConvForProton() 00058 { 00059 } 00060 00061 00062 G4double G4RToEConvForProton::Convert(G4double rangeCut, const G4Material* ) 00063 { 00064 // Simple formula 00065 // range = Ekin/(100*keV)*(1*mm); 00066 return (rangeCut/(1.0*mm)) * (100.0*keV); 00067 } 00068 00069 00070 // ********************************************************************** 00071 // ************************* ComputeLoss ******************************** 00072 // ********************************************************************** 00073 G4double G4RToEConvForProton::ComputeLoss(G4double AtomicNumber, 00074 G4double KineticEnergy) const 00075 { 00076 // calculate dE/dx 00077 00078 static G4double Z; 00079 static G4double ionpot, tau0, taum, taul, ca, cba, cc; 00080 00081 G4double z2Particle = theParticle->GetPDGCharge()/eplus; 00082 z2Particle *= z2Particle; 00083 if (z2Particle < 0.1) return 0.0; 00084 00085 if( std::fabs(AtomicNumber-Z)>0.1 ){ 00086 // recalculate constants 00087 Z = AtomicNumber; 00088 G4double Z13 = std::exp(std::log(Z)/3.); 00089 tau0 = 0.1*Z13*MeV/proton_mass_c2; 00090 taum = 0.035*Z13*MeV/proton_mass_c2; 00091 taul = 2.*MeV/proton_mass_c2; 00092 ionpot = 1.6e-5*MeV*std::exp(0.9*std::log(Z)); 00093 cc = (taul+1.)*(taul+1.)*std::log(2.*electron_mass_c2*taul*(taul+2.)/ionpot)/(taul*(taul+2.))-1.; 00094 cc = 2.*twopi_mc2_rcl2*Z*cc*std::sqrt(taul); 00095 ca = cc/((1.-0.5*std::sqrt(tau0/taum))*tau0); 00096 cba = -0.5/std::sqrt(taum); 00097 } 00098 00099 G4double tau = KineticEnergy/theParticle->GetPDGMass(); 00100 G4double dEdx; 00101 if ( tau <= tau0 ) { 00102 dEdx = ca*(std::sqrt(tau)+cba*tau); 00103 } else { 00104 if( tau <= taul ) { 00105 dEdx = cc/std::sqrt(tau); 00106 } else { 00107 dEdx = (tau+1.)*(tau+1.)* 00108 std::log(2.*electron_mass_c2*tau*(tau+2.)/ionpot)/(tau*(tau+2.))-1.; 00109 dEdx = 2.*twopi_mc2_rcl2*Z*dEdx; 00110 } 00111 } 00112 return dEdx*z2Particle ; 00113 } 00114 00115 00116 // ********************************************************************** 00117 // ************************* Reset ******************************** 00118 // ********************************************************************** 00119 void G4RToEConvForProton::Reset() 00120 { 00121 // do nothing because loss tables and range vectors are not used 00122 return; 00123 }