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25 // 22 //
26 // 23 //
>> 24 // $Id: G4PhotoElectricEffect.cc,v 1.27 2002/05/02 11:37:22 maire Exp $
>> 25 // GEANT4 tag $Name: geant4-04-01 $
27 // 26 //
28 //------------------ G4PhotoElectricEffect phy << 27 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
29 // by Michel Maire, 24 May 1 << 28
30 // << 29 // 12-06-96, Added SelectRandomAtom() method, by M.Maire
31 // Modified by Michel Maire and Vladimir Ivanc << 30 // 21-06-96, SetCuts implementation, M.Maire
32 // << 31 // 17-09-96, PartialSumSigma(i)
33 // ------------------------------------------- << 32 // split of ComputeBindingEnergy, M.Maire
>> 33 // 08-01-97, crossection table + meanfreepath table, M.Maire
>> 34 // 13-03-97, adapted for the new physics scheme, M.Maire
>> 35 // 28-03-97, protection in BuildPhysicsTable, M.Maire
>> 36 // 04-06-98, in DoIt, secondary production condition:
>> 37 // range > G4std::min(threshold,safety)
>> 38 // 13-08-98, new methods SetBining() PrintInfo()
>> 39 // 17-11-98, use table of Atomic shells in PostStepDoIt
>> 40 // 06-01-99, use Sandia crossSection below 50 keV, V.Grichine mma
>> 41 // 20-05-99, protection against very low energy photons ,L.Urban
>> 42 // 08-06-99, removed this above protection from the DoIt. mma
>> 43 // 21-06-00, in DoIt, killing photon: aParticleChange.SetEnergyChange(0.); mma
>> 44 // 22-06-00, in DoIt, absorbe very low energy photon (back to 20-05-99); mma
>> 45 // 22-02-01, back to 08-06-99 after correc in SandiaTable (materials-V03-00-05)
>> 46 // 28-05-01, V.Ivanchenko minor changes to provide ANSI -wall compilation
>> 47 // 13-07-01, DoIt: suppression of production cut of the electron (mma)
>> 48 // 06-08-01, new methods Store/Retrieve PhysicsTable (mma)
>> 49 // 06-08-01, BuildThePhysicsTable() called from constructor (mma)
>> 50 // 17-09-01, migration of Materials to pure STL (mma)
>> 51 // 20-09-01, DoIt: fminimalEnergy of generated electron = 1*eV (mma)
>> 52 // 01-10-01, come back to BuildPhysicsTable(const G4ParticleDefinition&)
>> 53 // 10-01-02, moved few function from icc to cc
>> 54 // 17-04-02, Keep only Sandia crossSections. Remove BuildPhysicsTables.
>> 55 // Simplify public interface (mma)
>> 56 // 29-04-02, Generate theta angle of the photoelectron from Sauter-Gavrila
>> 57 // distribution (mma)
>> 58 //
>> 59 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
>> 60 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
34 61
35 #include "G4PhotoElectricEffect.hh" 62 #include "G4PhotoElectricEffect.hh"
36 #include "G4SystemOfUnits.hh" << 63 #include "G4UnitsTable.hh"
37 #include "G4PEEffectFluoModel.hh" <<
38 #include "G4Electron.hh" <<
39 #include "G4EmParameters.hh" <<
40 64
41 //....oooOO0OOooo........oooOO0OOooo........oo 65 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
>> 66
>> 67 // constructor
>> 68
>> 69 G4PhotoElectricEffect::G4PhotoElectricEffect(const G4String& processName)
>> 70 : G4VDiscreteProcess (processName),
>> 71 fminimalEnergy(1*eV)
>> 72
>> 73 { PrintInfoDefinition();}
42 74
43 using namespace std; << 75 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
>> 76
>> 77 // destructor
>> 78
>> 79 G4PhotoElectricEffect::~G4PhotoElectricEffect()
>> 80 { }
>> 81
>> 82 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
44 83
45 G4PhotoElectricEffect::G4PhotoElectricEffect(c << 84 G4double G4PhotoElectricEffect::ComputeCrossSectionPerAtom(G4double GammaEnergy,
46 G4ProcessType type):G4VEmProcess (processNam << 85 G4double AtomicNumber)
>> 86
>> 87 // returns the photoElectric cross Section in GEANT4 internal units
47 { 88 {
48 SetBuildTableFlag(false); << 89 G4double* SandiaCof
49 SetSecondaryParticle(G4Electron::Electron()) << 90 = G4SandiaTable::GetSandiaCofPerAtom((int)AtomicNumber,GammaEnergy);
50 SetProcessSubType(fPhotoElectricEffect); << 91
51 SetMinKinEnergyPrim(200*keV); << 92 G4double energy2 = GammaEnergy*GammaEnergy, energy3 = GammaEnergy*energy2,
>> 93 energy4 = energy2*energy2;
>> 94
>> 95 return SandiaCof[0]/GammaEnergy + SandiaCof[1]/energy2 +
>> 96 SandiaCof[2]/energy3 + SandiaCof[3]/energy4;
>> 97
52 } 98 }
53 99
54 //....oooOO0OOooo........oooOO0OOooo........oo 100 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
55 101
56 G4PhotoElectricEffect::~G4PhotoElectricEffect( << 102 G4double G4PhotoElectricEffect::ComputeMeanFreePath(G4double GammaEnergy,
57 << 103 G4Material* aMaterial)
58 //....oooOO0OOooo........oooOO0OOooo........oo <<
59 104
60 G4bool G4PhotoElectricEffect::IsApplicable(con << 105 // returns the gamma mean free path in GEANT4 internal units
61 { 106 {
62 return (&p == G4Gamma::Gamma()); << 107 G4double* SandiaCof = aMaterial->GetSandiaTable()
>> 108 ->GetSandiaCofForMaterial(GammaEnergy);
>> 109
>> 110 G4double energy2 = GammaEnergy*GammaEnergy, energy3 = GammaEnergy*energy2,
>> 111 energy4 = energy2*energy2;
>> 112
>> 113
>> 114 G4double SIGMA = SandiaCof[0]/GammaEnergy + SandiaCof[1]/energy2 +
>> 115 SandiaCof[2]/energy3 + SandiaCof[3]/energy4;
>> 116
>> 117 return SIGMA > DBL_MIN ? 1./SIGMA : DBL_MAX;
63 } 118 }
64 119
65 //....oooOO0OOooo........oooOO0OOooo........oo 120 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
>> 121
>> 122 G4VParticleChange* G4PhotoElectricEffect::PostStepDoIt(const G4Track& aTrack,
>> 123 const G4Step& aStep)
>> 124 //
>> 125 // Generate an electron resulting of a photo electric effect.
>> 126 // The incident photon disappear.
>> 127 // GEANT4 internal units
>> 128 //
>> 129
>> 130 { aParticleChange.Initialize(aTrack);
>> 131 G4Material* aMaterial = aTrack.GetMaterial();
>> 132
>> 133 const G4DynamicParticle* aDynamicPhoton = aTrack.GetDynamicParticle();
>> 134
>> 135 G4double PhotonEnergy = aDynamicPhoton->GetKineticEnergy();
>> 136 G4ParticleMomentum PhotonDirection = aDynamicPhoton->GetMomentumDirection();
>> 137
>> 138 // select randomly one element constituing the material.
>> 139 G4Element* anElement = SelectRandomAtom(aDynamicPhoton, aMaterial);
>> 140
>> 141 //
>> 142 // Photo electron
>> 143 //
>> 144
>> 145 G4int NbOfShells = anElement->GetNbOfAtomicShells();
>> 146 G4int i=0;
>> 147 while ((i<NbOfShells)&&(PhotonEnergy<anElement->GetAtomicShell(i))) i++;
>> 148
>> 149 if (i==NbOfShells) return G4VDiscreteProcess::PostStepDoIt(aTrack,aStep);
>> 150
>> 151 G4double ElecKineEnergy = PhotonEnergy - anElement->GetAtomicShell(i);
>> 152
>> 153 if (ElecKineEnergy > fminimalEnergy)
>> 154 {
>> 155 // direction of the photo electron
>> 156 //
>> 157 G4double cosTeta = ElecThetaDistribution(ElecKineEnergy);
>> 158 G4double sinTeta = sqrt(1.-cosTeta*cosTeta);
>> 159 G4double Phi = twopi * G4UniformRand();
>> 160 G4double dirx = sinTeta*cos(Phi),diry = sinTeta*sin(Phi),dirz = cosTeta;
>> 161 G4ThreeVector ElecDirection(dirx,diry,dirz);
>> 162 ElecDirection.rotateUz(PhotonDirection);
>> 163 //
>> 164 G4DynamicParticle* aElectron = new G4DynamicParticle (
>> 165 G4Electron::Electron(),ElecDirection, ElecKineEnergy);
>> 166 aParticleChange.SetNumberOfSecondaries(1);
>> 167 aParticleChange.AddSecondary(aElectron);
>> 168 }
>> 169 else
>> 170 {
>> 171 ElecKineEnergy = 0.;
>> 172 aParticleChange.SetNumberOfSecondaries(0);
>> 173 }
>> 174
>> 175 //
>> 176 // Kill the incident photon
>> 177 //
>> 178 aParticleChange.SetLocalEnergyDeposit(PhotonEnergy-ElecKineEnergy);
>> 179 aParticleChange.SetEnergyChange(0.);
>> 180 aParticleChange.SetStatusChange(fStopAndKill);
66 181
67 void G4PhotoElectricEffect::InitialiseProcess( << 182 // Reset NbOfInteractionLengthLeft and return aParticleChange
68 { << 183 return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
69 if(!isInitialised) { <<
70 isInitialised = true; <<
71 if(nullptr == EmModel()) { SetEmModel(new <<
72 G4EmParameters* param = G4EmParameters::In <<
73 EmModel()->SetLowEnergyLimit(param->MinKin <<
74 EmModel()->SetHighEnergyLimit(param->MaxKi <<
75 AddEmModel(1, EmModel()); <<
76 } <<
77 } 184 }
78 185
79 //....oooOO0OOooo........oooOO0OOooo........oo 186 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
80 187
81 void G4PhotoElectricEffect::ProcessDescription << 188 G4Element* G4PhotoElectricEffect::SelectRandomAtom(
>> 189 const G4DynamicParticle* aDynamicPhoton,
>> 190 G4Material* aMaterial)
82 { 191 {
83 out << " Photoelectric effect"; << 192 // select randomly 1 element within the material
84 G4VEmProcess::ProcessDescription(out); << 193
>> 194 const G4int NumberOfElements = aMaterial->GetNumberOfElements();
>> 195 const G4ElementVector* theElementVector = aMaterial->GetElementVector();
>> 196 if (NumberOfElements == 1) return (*theElementVector)[0];
>> 197
>> 198 G4double GammaEnergy = aDynamicPhoton->GetKineticEnergy();
>> 199 const G4double* NbOfAtomsPerVolume = aMaterial->GetVecNbOfAtomsPerVolume();
>> 200
>> 201 G4double PartialSumSigma = 0. ;
>> 202 G4double rval = G4UniformRand();
>> 203
>> 204 for ( G4int elm=0 ; elm < NumberOfElements ; elm++ )
>> 205 {PartialSumSigma += NbOfAtomsPerVolume[elm] *
>> 206 ComputeCrossSectionPerAtom(GammaEnergy,
>> 207 (*theElementVector)[elm]->GetZ());
>> 208 if (rval<=PartialSumSigma*MeanFreePath) return ((*theElementVector)[elm]);
>> 209 }
>> 210 return ((*theElementVector)[NumberOfElements-1]);
85 } 211 }
>> 212
>> 213 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
>> 214
>> 215 G4double G4PhotoElectricEffect::ElecThetaDistribution(G4double kineEnergy)
>> 216 {
>> 217 // Compute Theta distribution of the emitted electron, with respect to the
>> 218 // incident Gamma.
>> 219 // The Sauter-Gavrila distribution for the K-shell is used.
>> 220 //
>> 221 G4double gamma = 1. + kineEnergy/electron_mass_c2;
>> 222 G4double beta = sqrt(gamma*gamma-1.)/gamma;
>> 223 G4double b = 0.5*gamma*(gamma-1.)*(gamma-2);
>> 224
>> 225 G4double rndm,costeta,term,greject,grejsup;
>> 226 if (gamma < 2.) grejsup = gamma*gamma*(1.+b-beta*b);
>> 227 else grejsup = gamma*gamma*(1.+b+beta*b);
>> 228
>> 229 do { rndm = 1.-2*G4UniformRand();
>> 230 costeta = (rndm+beta)/(rndm*beta+1.);
>> 231 term = 1.-beta*costeta;
>> 232 greject = (1.-costeta*costeta)*(1.+b*term)/(term*term);
>> 233 } while(greject < G4UniformRand()*grejsup);
>> 234
>> 235 return costeta;
>> 236
>> 237 }
>> 238
>> 239 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
>> 240
>> 241 void G4PhotoElectricEffect::PrintInfoDefinition()
>> 242 {
>> 243 G4String comments = "Total cross sections from Sandia parametrisation. ";
>> 244
>> 245 G4cout << G4endl << GetProcessName() << ": " << comments << G4endl;
>> 246 }
86 247
87 //....oooOO0OOooo........oooOO0OOooo........oo 248 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
88 249