[1316] | 1 | // |
---|
| 2 | // ******************************************************************** |
---|
| 3 | // * License and Disclaimer * |
---|
| 4 | // * * |
---|
| 5 | // * The Geant4 software is copyright of the Copyright Holders of * |
---|
| 6 | // * the Geant4 Collaboration. It is provided under the terms and * |
---|
| 7 | // * conditions of the Geant4 Software License, included in the file * |
---|
| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
---|
| 9 | // * include a list of copyright holders. * |
---|
| 10 | // * * |
---|
| 11 | // * Neither the authors of this software system, nor their employing * |
---|
| 12 | // * institutes,nor the agencies providing financial support for this * |
---|
| 13 | // * work make any representation or warranty, express or implied, * |
---|
| 14 | // * regarding this software system or assume any liability for its * |
---|
| 15 | // * use. Please see the license in the file LICENSE and URL above * |
---|
| 16 | // * for the full disclaimer and the limitation of liability. * |
---|
| 17 | // * * |
---|
| 18 | // * This code implementation is the result of the scientific and * |
---|
| 19 | // * technical work of the GEANT4 collaboration. * |
---|
| 20 | // * By using, copying, modifying or distributing the software (or * |
---|
| 21 | // * any work based on the software) you agree to acknowledge its * |
---|
| 22 | // * use in resulting scientific publications, and indicate your * |
---|
| 23 | // * acceptance of all terms of the Geant4 Software license. * |
---|
| 24 | // ******************************************************************** |
---|
| 25 | // |
---|
[1340] | 26 | // $Id: G4Penelope08GammaConversionModel.cc,v 1.4 2010/07/28 07:09:16 pandola Exp $ |
---|
[1347] | 27 | // GEANT4 tag $Name: geant4-09-04-ref-00 $ |
---|
[1316] | 28 | // |
---|
| 29 | // Author: Luciano Pandola |
---|
| 30 | // |
---|
| 31 | // History: |
---|
| 32 | // -------- |
---|
| 33 | // 13 Jan 2010 L Pandola First implementation (updated to Penelope08) |
---|
| 34 | // |
---|
| 35 | |
---|
| 36 | #include "G4Penelope08GammaConversionModel.hh" |
---|
| 37 | #include "G4ParticleDefinition.hh" |
---|
| 38 | #include "G4MaterialCutsCouple.hh" |
---|
| 39 | #include "G4ProductionCutsTable.hh" |
---|
| 40 | #include "G4DynamicParticle.hh" |
---|
| 41 | #include "G4Element.hh" |
---|
| 42 | #include "G4Gamma.hh" |
---|
| 43 | #include "G4Electron.hh" |
---|
| 44 | #include "G4Positron.hh" |
---|
| 45 | #include "G4PhysicsFreeVector.hh" |
---|
| 46 | |
---|
| 47 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
| 48 | |
---|
| 49 | |
---|
| 50 | G4Penelope08GammaConversionModel::G4Penelope08GammaConversionModel(const G4ParticleDefinition*, |
---|
| 51 | const G4String& nam) |
---|
| 52 | :G4VEmModel(nam),logAtomicCrossSection(0),fEffectiveCharge(0),fMaterialInvScreeningRadius(0), |
---|
| 53 | fScreeningFunction(0),isInitialised(false) |
---|
| 54 | { |
---|
| 55 | fIntrinsicLowEnergyLimit = 2.0*electron_mass_c2; |
---|
| 56 | fIntrinsicHighEnergyLimit = 100.0*GeV; |
---|
| 57 | fSmallEnergy = 1.1*MeV; |
---|
| 58 | InitializeScreeningRadii(); |
---|
| 59 | |
---|
| 60 | // SetLowEnergyLimit(fIntrinsicLowEnergyLimit); |
---|
| 61 | SetHighEnergyLimit(fIntrinsicHighEnergyLimit); |
---|
| 62 | // |
---|
| 63 | verboseLevel= 0; |
---|
| 64 | // Verbosity scale: |
---|
| 65 | // 0 = nothing |
---|
| 66 | // 1 = warning for energy non-conservation |
---|
| 67 | // 2 = details of energy budget |
---|
| 68 | // 3 = calculation of cross sections, file openings, sampling of atoms |
---|
| 69 | // 4 = entering in methods |
---|
| 70 | } |
---|
| 71 | |
---|
| 72 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
| 73 | |
---|
| 74 | G4Penelope08GammaConversionModel::~G4Penelope08GammaConversionModel() |
---|
| 75 | { |
---|
| 76 | std::map <const G4int,G4PhysicsFreeVector*>::iterator i; |
---|
| 77 | if (logAtomicCrossSection) |
---|
| 78 | { |
---|
| 79 | for (i=logAtomicCrossSection->begin();i != logAtomicCrossSection->end();i++) |
---|
| 80 | if (i->second) delete i->second; |
---|
| 81 | delete logAtomicCrossSection; |
---|
| 82 | } |
---|
| 83 | if (fEffectiveCharge) |
---|
| 84 | delete fEffectiveCharge; |
---|
| 85 | if (fMaterialInvScreeningRadius) |
---|
| 86 | delete fMaterialInvScreeningRadius; |
---|
| 87 | if (fScreeningFunction) |
---|
| 88 | delete fScreeningFunction; |
---|
| 89 | } |
---|
| 90 | |
---|
| 91 | |
---|
| 92 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
| 93 | |
---|
| 94 | void G4Penelope08GammaConversionModel::Initialise(const G4ParticleDefinition*, |
---|
| 95 | const G4DataVector&) |
---|
| 96 | { |
---|
| 97 | if (verboseLevel > 3) |
---|
| 98 | G4cout << "Calling G4Penelope08GammaConversionModel::Initialise()" << G4endl; |
---|
| 99 | |
---|
| 100 | // logAtomicCrossSection is created only once, since it is never cleared |
---|
| 101 | if (!logAtomicCrossSection) |
---|
| 102 | logAtomicCrossSection = new std::map<const G4int,G4PhysicsFreeVector*>; |
---|
| 103 | |
---|
| 104 | //delete old material data... |
---|
| 105 | if (fEffectiveCharge) |
---|
| 106 | { |
---|
| 107 | delete fEffectiveCharge; |
---|
| 108 | fEffectiveCharge = 0; |
---|
| 109 | } |
---|
| 110 | if (fMaterialInvScreeningRadius) |
---|
| 111 | { |
---|
| 112 | delete fMaterialInvScreeningRadius; |
---|
| 113 | fMaterialInvScreeningRadius = 0; |
---|
| 114 | } |
---|
| 115 | if (fScreeningFunction) |
---|
| 116 | { |
---|
| 117 | delete fScreeningFunction; |
---|
| 118 | fScreeningFunction = 0; |
---|
| 119 | } |
---|
| 120 | //and create new ones |
---|
| 121 | fEffectiveCharge = new std::map<const G4Material*,G4double>; |
---|
| 122 | fMaterialInvScreeningRadius = new std::map<const G4Material*,G4double>; |
---|
| 123 | fScreeningFunction = new std::map<const G4Material*,std::pair<G4double,G4double> >; |
---|
| 124 | |
---|
| 125 | if (verboseLevel > 0) { |
---|
| 126 | G4cout << "Penelope Gamma Conversion model is initialized " << G4endl |
---|
| 127 | << "Energy range: " |
---|
| 128 | << LowEnergyLimit() / MeV << " MeV - " |
---|
| 129 | << HighEnergyLimit() / GeV << " GeV" |
---|
| 130 | << G4endl; |
---|
| 131 | } |
---|
| 132 | |
---|
| 133 | if(isInitialised) return; |
---|
| 134 | fParticleChange = GetParticleChangeForGamma(); |
---|
| 135 | isInitialised = true; |
---|
| 136 | } |
---|
| 137 | |
---|
| 138 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
| 139 | |
---|
| 140 | G4double G4Penelope08GammaConversionModel::ComputeCrossSectionPerAtom( |
---|
| 141 | const G4ParticleDefinition*, |
---|
| 142 | G4double energy, |
---|
| 143 | G4double Z, G4double, |
---|
| 144 | G4double, G4double) |
---|
| 145 | { |
---|
| 146 | // |
---|
| 147 | // Penelope model. |
---|
| 148 | // Cross section (including triplet production) read from database and managed |
---|
| 149 | // through the G4CrossSectionHandler utility. Cross section data are from |
---|
| 150 | // M.J. Berger and J.H. Hubbel (XCOM), Report NBSIR 887-3598 |
---|
| 151 | // |
---|
| 152 | |
---|
| 153 | if (energy < fIntrinsicLowEnergyLimit) |
---|
| 154 | return 0; |
---|
| 155 | |
---|
| 156 | G4int iZ = (G4int) Z; |
---|
| 157 | |
---|
| 158 | //read data files |
---|
| 159 | if (!logAtomicCrossSection->count(iZ)) |
---|
| 160 | ReadDataFile(iZ); |
---|
| 161 | //now it should be ok |
---|
| 162 | if (!logAtomicCrossSection->count(iZ)) |
---|
| 163 | { |
---|
| 164 | G4cout << "Problem in G4Penelope08GammaConversion::ComputeCrossSectionPerAtom" |
---|
| 165 | << G4endl; |
---|
| 166 | G4Exception(); |
---|
| 167 | } |
---|
| 168 | |
---|
| 169 | G4double cs = 0; |
---|
[1337] | 170 | G4double logene = std::log(energy); |
---|
[1316] | 171 | G4PhysicsFreeVector* theVec = logAtomicCrossSection->find(iZ)->second; |
---|
| 172 | |
---|
| 173 | G4double logXS = theVec->Value(logene); |
---|
[1337] | 174 | cs = std::exp(logXS); |
---|
[1316] | 175 | |
---|
| 176 | if (verboseLevel > 2) |
---|
| 177 | G4cout << "Gamma conversion cross section at " << energy/MeV << " MeV for Z=" << Z << |
---|
| 178 | " = " << cs/barn << " barn" << G4endl; |
---|
| 179 | return cs; |
---|
| 180 | } |
---|
| 181 | |
---|
| 182 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
| 183 | |
---|
| 184 | void |
---|
| 185 | G4Penelope08GammaConversionModel::SampleSecondaries(std::vector<G4DynamicParticle*>* fvect, |
---|
| 186 | const G4MaterialCutsCouple* couple, |
---|
| 187 | const G4DynamicParticle* aDynamicGamma, |
---|
| 188 | G4double, |
---|
| 189 | G4double) |
---|
| 190 | { |
---|
| 191 | // |
---|
| 192 | // Penelope model. |
---|
| 193 | // Final state is sampled according to the Bethe-Heitler model with Coulomb |
---|
| 194 | // corrections, according to the semi-empirical model of |
---|
| 195 | // J. Baro' et al., Radiat. Phys. Chem. 44 (1994) 531. |
---|
| 196 | // |
---|
| 197 | // The model uses the high energy Coulomb correction from |
---|
| 198 | // H. Davies et al., Phys. Rev. 93 (1954) 788 |
---|
| 199 | // and atomic screening radii tabulated from |
---|
| 200 | // J.H. Hubbel et al., J. Phys. Chem. Ref. Data 9 (1980) 1023 |
---|
| 201 | // for Z= 1 to 92. |
---|
| 202 | // |
---|
| 203 | if (verboseLevel > 3) |
---|
| 204 | G4cout << "Calling SamplingSecondaries() of G4Penelope08GammaConversionModel" << G4endl; |
---|
| 205 | |
---|
| 206 | G4double photonEnergy = aDynamicGamma->GetKineticEnergy(); |
---|
| 207 | |
---|
| 208 | // Always kill primary |
---|
| 209 | fParticleChange->ProposeTrackStatus(fStopAndKill); |
---|
| 210 | fParticleChange->SetProposedKineticEnergy(0.); |
---|
| 211 | |
---|
| 212 | if (photonEnergy <= fIntrinsicLowEnergyLimit) |
---|
| 213 | { |
---|
| 214 | fParticleChange->ProposeLocalEnergyDeposit(photonEnergy); |
---|
| 215 | return ; |
---|
| 216 | } |
---|
| 217 | |
---|
| 218 | G4ParticleMomentum photonDirection = aDynamicGamma->GetMomentumDirection(); |
---|
| 219 | const G4Material* mat = couple->GetMaterial(); |
---|
| 220 | |
---|
| 221 | //check if material data are available |
---|
| 222 | if (!fEffectiveCharge->count(mat)) |
---|
| 223 | InitializeScreeningFunctions(mat); |
---|
| 224 | if (!fEffectiveCharge->count(mat)) |
---|
| 225 | { |
---|
| 226 | G4cout << "Problem in G4Penelope08GammaConversion::SampleSecondaries()" << G4endl; |
---|
| 227 | G4cout << "Unable to allocate the EffectiveCharge data" << G4endl; |
---|
| 228 | G4Exception(); |
---|
| 229 | } |
---|
| 230 | |
---|
| 231 | // eps is the fraction of the photon energy assigned to e- (including rest mass) |
---|
| 232 | G4double eps = 0; |
---|
| 233 | G4double eki = electron_mass_c2/photonEnergy; |
---|
| 234 | |
---|
| 235 | //Do it fast for photon energy < 1.1 MeV (close to threshold) |
---|
| 236 | if (photonEnergy < fSmallEnergy) |
---|
| 237 | eps = eki + (1.0-2.0*eki)*G4UniformRand(); |
---|
| 238 | else |
---|
| 239 | { |
---|
| 240 | //Complete calculation |
---|
| 241 | G4double effC = fEffectiveCharge->find(mat)->second; |
---|
| 242 | G4double alz = effC*fine_structure_const; |
---|
[1337] | 243 | G4double T = std::sqrt(2.0*eki); |
---|
[1316] | 244 | G4double F00=(-1.774-1.210e1*alz+1.118e1*alz*alz)*T |
---|
| 245 | +(8.523+7.326e1*alz-4.441e1*alz*alz)*T*T |
---|
| 246 | -(1.352e1+1.211e2*alz-9.641e1*alz*alz)*T*T*T |
---|
| 247 | +(8.946+6.205e1*alz-6.341e1*alz*alz)*T*T*T*T; |
---|
| 248 | |
---|
| 249 | G4double F0b = fScreeningFunction->find(mat)->second.second; |
---|
| 250 | G4double g0 = F0b + F00; |
---|
| 251 | G4double invRad = fMaterialInvScreeningRadius->find(mat)->second; |
---|
| 252 | G4double bmin = 4.0*eki/invRad; |
---|
| 253 | std::pair<G4double,G4double> scree = GetScreeningFunctions(bmin); |
---|
| 254 | G4double g1 = scree.first; |
---|
| 255 | G4double g2 = scree.second; |
---|
| 256 | G4double g1min = g1+g0; |
---|
| 257 | G4double g2min = g2+g0; |
---|
| 258 | G4double xr = 0.5-eki; |
---|
| 259 | G4double a1 = 2.*g1min*xr*xr/3.; |
---|
| 260 | G4double p1 = a1/(a1+g2min); |
---|
| 261 | |
---|
| 262 | G4bool loopAgain = false; |
---|
| 263 | //Random sampling of eps |
---|
| 264 | do{ |
---|
| 265 | loopAgain = false; |
---|
| 266 | if (G4UniformRand() <= p1) |
---|
| 267 | { |
---|
| 268 | G4double ru2m1 = 2.0*G4UniformRand()-1.0; |
---|
| 269 | if (ru2m1 < 0) |
---|
[1337] | 270 | eps = 0.5-xr*std::pow(std::abs(ru2m1),1./3.); |
---|
[1316] | 271 | else |
---|
[1337] | 272 | eps = 0.5+xr*std::pow(ru2m1,1./3.); |
---|
[1316] | 273 | G4double B = eki/(invRad*eps*(1.0-eps)); |
---|
| 274 | scree = GetScreeningFunctions(B); |
---|
| 275 | g1 = scree.first; |
---|
| 276 | g1 = std::max(g1+g0,0.); |
---|
| 277 | if (G4UniformRand()*g1min > g1) |
---|
| 278 | loopAgain = true; |
---|
| 279 | } |
---|
| 280 | else |
---|
| 281 | { |
---|
| 282 | eps = eki+2.0*xr*G4UniformRand(); |
---|
| 283 | G4double B = eki/(invRad*eps*(1.0-eps)); |
---|
| 284 | scree = GetScreeningFunctions(B); |
---|
| 285 | g2 = scree.second; |
---|
| 286 | g2 = std::max(g2+g0,0.); |
---|
| 287 | if (G4UniformRand()*g2min > g2) |
---|
| 288 | loopAgain = true; |
---|
| 289 | } |
---|
| 290 | }while(loopAgain); |
---|
| 291 | |
---|
| 292 | } |
---|
| 293 | if (verboseLevel > 4) |
---|
| 294 | G4cout << "Sampled eps = " << eps << G4endl; |
---|
| 295 | |
---|
| 296 | G4double electronTotEnergy = eps*photonEnergy; |
---|
| 297 | G4double positronTotEnergy = (1.0-eps)*photonEnergy; |
---|
| 298 | |
---|
| 299 | // Scattered electron (positron) angles. ( Z - axis along the parent photon) |
---|
| 300 | |
---|
| 301 | //electron kinematics |
---|
| 302 | G4double electronKineEnergy = std::max(0.,electronTotEnergy - electron_mass_c2) ; |
---|
| 303 | G4double costheta_el = G4UniformRand()*2.0-1.0; |
---|
| 304 | G4double kk = std::sqrt(electronKineEnergy*(electronKineEnergy+2.*electron_mass_c2)); |
---|
| 305 | costheta_el = (costheta_el*electronTotEnergy+kk)/(electronTotEnergy+costheta_el*kk); |
---|
| 306 | G4double phi_el = twopi * G4UniformRand() ; |
---|
| 307 | G4double dirX_el = std::sqrt(1.-costheta_el*costheta_el) * std::cos(phi_el); |
---|
| 308 | G4double dirY_el = std::sqrt(1.-costheta_el*costheta_el) * std::sin(phi_el); |
---|
| 309 | G4double dirZ_el = costheta_el; |
---|
| 310 | |
---|
| 311 | //positron kinematics |
---|
| 312 | G4double positronKineEnergy = std::max(0.,positronTotEnergy - electron_mass_c2) ; |
---|
| 313 | G4double costheta_po = G4UniformRand()*2.0-1.0; |
---|
| 314 | kk = std::sqrt(positronKineEnergy*(positronKineEnergy+2.*electron_mass_c2)); |
---|
| 315 | costheta_po = (costheta_po*positronTotEnergy+kk)/(positronTotEnergy+costheta_po*kk); |
---|
| 316 | G4double phi_po = twopi * G4UniformRand() ; |
---|
| 317 | G4double dirX_po = std::sqrt(1.-costheta_po*costheta_po) * std::cos(phi_po); |
---|
| 318 | G4double dirY_po = std::sqrt(1.-costheta_po*costheta_po) * std::sin(phi_po); |
---|
| 319 | G4double dirZ_po = costheta_po; |
---|
| 320 | |
---|
| 321 | // Kinematics of the created pair: |
---|
| 322 | // the electron and positron are assumed to have a symetric angular |
---|
| 323 | // distribution with respect to the Z axis along the parent photon |
---|
| 324 | G4double localEnergyDeposit = 0. ; |
---|
| 325 | |
---|
| 326 | if (electronKineEnergy > 0.0) |
---|
| 327 | { |
---|
| 328 | G4ThreeVector electronDirection ( dirX_el, dirY_el, dirZ_el); |
---|
| 329 | electronDirection.rotateUz(photonDirection); |
---|
| 330 | G4DynamicParticle* electron = new G4DynamicParticle (G4Electron::Electron(), |
---|
| 331 | electronDirection, |
---|
| 332 | electronKineEnergy); |
---|
| 333 | fvect->push_back(electron); |
---|
| 334 | } |
---|
| 335 | else |
---|
| 336 | { |
---|
| 337 | localEnergyDeposit += electronKineEnergy; |
---|
| 338 | electronKineEnergy = 0; |
---|
| 339 | } |
---|
| 340 | |
---|
| 341 | //Generate the positron. Real particle in any case, because it will annihilate. If below |
---|
| 342 | //threshold, produce it at rest |
---|
| 343 | if (positronKineEnergy < 0.0) |
---|
| 344 | { |
---|
| 345 | localEnergyDeposit += positronKineEnergy; |
---|
| 346 | positronKineEnergy = 0; //produce it at rest |
---|
| 347 | } |
---|
| 348 | G4ThreeVector positronDirection(dirX_po,dirY_po,dirZ_po); |
---|
| 349 | positronDirection.rotateUz(photonDirection); |
---|
| 350 | G4DynamicParticle* positron = new G4DynamicParticle(G4Positron::Positron(), |
---|
| 351 | positronDirection, positronKineEnergy); |
---|
| 352 | fvect->push_back(positron); |
---|
| 353 | |
---|
| 354 | //Add rest of energy to the local energy deposit |
---|
| 355 | fParticleChange->ProposeLocalEnergyDeposit(localEnergyDeposit); |
---|
| 356 | |
---|
| 357 | if (verboseLevel > 1) |
---|
| 358 | { |
---|
| 359 | G4cout << "-----------------------------------------------------------" << G4endl; |
---|
| 360 | G4cout << "Energy balance from G4Penelope08GammaConversion" << G4endl; |
---|
| 361 | G4cout << "Incoming photon energy: " << photonEnergy/keV << " keV" << G4endl; |
---|
| 362 | G4cout << "-----------------------------------------------------------" << G4endl; |
---|
| 363 | if (electronKineEnergy) |
---|
| 364 | G4cout << "Electron (explicitely produced) " << electronKineEnergy/keV << " keV" |
---|
| 365 | << G4endl; |
---|
| 366 | if (positronKineEnergy) |
---|
| 367 | G4cout << "Positron (not at rest) " << positronKineEnergy/keV << " keV" << G4endl; |
---|
| 368 | G4cout << "Rest masses of e+/- " << 2.0*electron_mass_c2/keV << " keV" << G4endl; |
---|
| 369 | if (localEnergyDeposit) |
---|
| 370 | G4cout << "Local energy deposit " << localEnergyDeposit/keV << " keV" << G4endl; |
---|
| 371 | G4cout << "Total final state: " << (electronKineEnergy+positronKineEnergy+ |
---|
| 372 | localEnergyDeposit+2.0*electron_mass_c2)/keV << |
---|
| 373 | " keV" << G4endl; |
---|
| 374 | G4cout << "-----------------------------------------------------------" << G4endl; |
---|
| 375 | } |
---|
| 376 | if (verboseLevel > 0) |
---|
| 377 | { |
---|
| 378 | G4double energyDiff = std::fabs(electronKineEnergy+positronKineEnergy+ |
---|
| 379 | localEnergyDeposit+2.0*electron_mass_c2-photonEnergy); |
---|
| 380 | if (energyDiff > 0.05*keV) |
---|
| 381 | G4cout << "Warning from G4Penelope08GammaConversion: problem with energy conservation: " |
---|
| 382 | << (electronKineEnergy+positronKineEnergy+ |
---|
| 383 | localEnergyDeposit+2.0*electron_mass_c2)/keV |
---|
| 384 | << " keV (final) vs. " << photonEnergy/keV << " keV (initial)" << G4endl; |
---|
| 385 | } |
---|
| 386 | } |
---|
| 387 | |
---|
| 388 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
| 389 | |
---|
| 390 | void G4Penelope08GammaConversionModel::ReadDataFile(const G4int Z) |
---|
| 391 | { |
---|
| 392 | if (verboseLevel > 2) |
---|
| 393 | { |
---|
| 394 | G4cout << "G4Penelope08GammaConversionModel::ReadDataFile()" << G4endl; |
---|
| 395 | G4cout << "Going to read Gamma Conversion data files for Z=" << Z << G4endl; |
---|
| 396 | } |
---|
| 397 | |
---|
| 398 | char* path = getenv("G4LEDATA"); |
---|
| 399 | if (!path) |
---|
| 400 | { |
---|
| 401 | G4String excep = |
---|
| 402 | "G4Penelope08GammaConversionModel - G4LEDATA environment variable not set!"; |
---|
| 403 | G4Exception(excep); |
---|
| 404 | } |
---|
| 405 | |
---|
| 406 | /* |
---|
| 407 | Read the cross section file |
---|
| 408 | */ |
---|
| 409 | std::ostringstream ost; |
---|
| 410 | if (Z>9) |
---|
| 411 | ost << path << "/penelope/pairproduction/pdgpp" << Z << ".p08"; |
---|
| 412 | else |
---|
| 413 | ost << path << "/penelope/pairproduction/pdgpp0" << Z << ".p08"; |
---|
| 414 | std::ifstream file(ost.str().c_str()); |
---|
| 415 | if (!file.is_open()) |
---|
| 416 | { |
---|
| 417 | G4String excep = "G4Penelope08GammaConversionModel - data file " + |
---|
| 418 | G4String(ost.str()) + " not found!"; |
---|
| 419 | G4Exception(excep); |
---|
| 420 | } |
---|
| 421 | |
---|
| 422 | //I have to know in advance how many points are in the data list |
---|
| 423 | //to initialize the G4PhysicsFreeVector() |
---|
| 424 | size_t ndata=0; |
---|
| 425 | G4String line; |
---|
| 426 | while( getline(file, line) ) |
---|
| 427 | ndata++; |
---|
| 428 | ndata -= 1; //remove one header line |
---|
| 429 | //G4cout << "Found: " << ndata << " lines" << G4endl; |
---|
| 430 | |
---|
| 431 | file.clear(); |
---|
| 432 | file.close(); |
---|
| 433 | file.open(ost.str().c_str()); |
---|
| 434 | G4int readZ =0; |
---|
| 435 | file >> readZ; |
---|
| 436 | |
---|
| 437 | if (verboseLevel > 3) |
---|
| 438 | G4cout << "Element Z=" << Z << G4endl; |
---|
| 439 | |
---|
| 440 | //check the right file is opened. |
---|
| 441 | if (readZ != Z) |
---|
| 442 | { |
---|
| 443 | G4cout << "G4Penelope08GammaConversionModel::ReadDataFile()" << G4endl; |
---|
| 444 | G4cout << "Corrupted data file for Z=" << Z << G4endl; |
---|
| 445 | G4Exception(); |
---|
| 446 | } |
---|
| 447 | |
---|
| 448 | G4PhysicsFreeVector* theVec = new G4PhysicsFreeVector(ndata); |
---|
| 449 | G4double ene=0,xs=0; |
---|
| 450 | for (size_t i=0;i<ndata;i++) |
---|
| 451 | { |
---|
| 452 | file >> ene >> xs; |
---|
| 453 | //dimensional quantities |
---|
| 454 | ene *= eV; |
---|
| 455 | xs *= barn; |
---|
| 456 | if (xs < 1e-40*cm2) //protection against log(0) |
---|
| 457 | xs = 1e-40*cm2; |
---|
[1337] | 458 | theVec->PutValue(i,std::log(ene),std::log(xs)); |
---|
[1316] | 459 | } |
---|
| 460 | file.close(); |
---|
| 461 | |
---|
| 462 | if (!logAtomicCrossSection) |
---|
| 463 | { |
---|
| 464 | G4cout << "G4Penelope08RayleighModel::ReadDataFile()" << G4endl; |
---|
| 465 | G4cout << "Problem with allocation of logAtomicCrossSection data table " << G4endl; |
---|
| 466 | G4Exception(); |
---|
| 467 | } |
---|
| 468 | logAtomicCrossSection->insert(std::make_pair(Z,theVec)); |
---|
| 469 | |
---|
| 470 | return; |
---|
| 471 | |
---|
| 472 | } |
---|
| 473 | |
---|
| 474 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
| 475 | |
---|
| 476 | void G4Penelope08GammaConversionModel::InitializeScreeningRadii() |
---|
| 477 | { |
---|
| 478 | G4double temp[99] = {1.2281e+02,7.3167e+01,6.9228e+01,6.7301e+01,6.4696e+01, |
---|
| 479 | 6.1228e+01,5.7524e+01,5.4033e+01,5.0787e+01,4.7851e+01,4.6373e+01, |
---|
| 480 | 4.5401e+01,4.4503e+01,4.3815e+01,4.3074e+01,4.2321e+01,4.1586e+01, |
---|
| 481 | 4.0953e+01,4.0524e+01,4.0256e+01,3.9756e+01,3.9144e+01,3.8462e+01, |
---|
| 482 | 3.7778e+01,3.7174e+01,3.6663e+01,3.5986e+01,3.5317e+01,3.4688e+01, |
---|
| 483 | 3.4197e+01,3.3786e+01,3.3422e+01,3.3068e+01,3.2740e+01,3.2438e+01, |
---|
| 484 | 3.2143e+01,3.1884e+01,3.1622e+01,3.1438e+01,3.1142e+01,3.0950e+01, |
---|
| 485 | 3.0758e+01,3.0561e+01,3.0285e+01,3.0097e+01,2.9832e+01,2.9581e+01, |
---|
| 486 | 2.9411e+01,2.9247e+01,2.9085e+01,2.8930e+01,2.8721e+01,2.8580e+01, |
---|
| 487 | 2.8442e+01,2.8312e+01,2.8139e+01,2.7973e+01,2.7819e+01,2.7675e+01, |
---|
| 488 | 2.7496e+01,2.7285e+01,2.7093e+01,2.6911e+01,2.6705e+01,2.6516e+01, |
---|
| 489 | 2.6304e+01,2.6108e+01,2.5929e+01,2.5730e+01,2.5577e+01,2.5403e+01, |
---|
| 490 | 2.5245e+01,2.5100e+01,2.4941e+01,2.4790e+01,2.4655e+01,2.4506e+01, |
---|
| 491 | 2.4391e+01,2.4262e+01,2.4145e+01,2.4039e+01,2.3922e+01,2.3813e+01, |
---|
| 492 | 2.3712e+01,2.3621e+01,2.3523e+01,2.3430e+01,2.3331e+01,2.3238e+01, |
---|
| 493 | 2.3139e+01,2.3048e+01,2.2967e+01,2.2833e+01,2.2694e+01,2.2624e+01, |
---|
| 494 | 2.2545e+01,2.2446e+01,2.2358e+01,2.2264e+01}; |
---|
| 495 | |
---|
| 496 | //copy temporary vector in class data member |
---|
| 497 | for (G4int i=0;i<99;i++) |
---|
| 498 | fAtomicScreeningRadius[i] = temp[i]; |
---|
| 499 | } |
---|
| 500 | |
---|
| 501 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
| 502 | |
---|
| 503 | void G4Penelope08GammaConversionModel::InitializeScreeningFunctions(const G4Material* material) |
---|
| 504 | { |
---|
| 505 | // This is subroutine GPPa0 of Penelope |
---|
| 506 | // |
---|
| 507 | // 1) calculate the effective Z for the purpose |
---|
| 508 | // |
---|
| 509 | G4double zeff = 0; |
---|
| 510 | G4int intZ = 0; |
---|
| 511 | G4int nElements = material->GetNumberOfElements(); |
---|
| 512 | const G4ElementVector* elementVector = material->GetElementVector(); |
---|
| 513 | |
---|
| 514 | //avoid calculations if only one building element! |
---|
| 515 | if (nElements == 1) |
---|
| 516 | { |
---|
| 517 | zeff = (*elementVector)[0]->GetZ(); |
---|
| 518 | intZ = (G4int) zeff; |
---|
| 519 | } |
---|
| 520 | else // many elements...let's do the calculation |
---|
| 521 | { |
---|
| 522 | const G4double* fractionVector = material->GetVecNbOfAtomsPerVolume(); |
---|
| 523 | |
---|
| 524 | G4double atot = 0; |
---|
| 525 | for (G4int i=0;i<nElements;i++) |
---|
| 526 | { |
---|
| 527 | G4double Zelement = (*elementVector)[i]->GetZ(); |
---|
| 528 | G4double Aelement = (*elementVector)[i]->GetA(); |
---|
| 529 | atot += Aelement*fractionVector[i]; |
---|
| 530 | zeff += Zelement*Aelement*fractionVector[i]; //average with the number of nuclei |
---|
| 531 | } |
---|
| 532 | atot /= material->GetTotNbOfAtomsPerVolume(); |
---|
| 533 | zeff /= (material->GetTotNbOfAtomsPerVolume()*atot); |
---|
| 534 | |
---|
| 535 | intZ = (G4int) (zeff+0.25); |
---|
| 536 | if (intZ <= 0) |
---|
| 537 | intZ = 1; |
---|
| 538 | if (intZ > 99) |
---|
| 539 | intZ = 99; |
---|
| 540 | } |
---|
| 541 | |
---|
| 542 | if (fEffectiveCharge) |
---|
| 543 | fEffectiveCharge->insert(std::make_pair(material,zeff)); |
---|
| 544 | |
---|
| 545 | // |
---|
| 546 | // 2) Calculate Coulomb Correction |
---|
| 547 | // |
---|
| 548 | G4double alz = fine_structure_const*zeff; |
---|
| 549 | G4double alzSquared = alz*alz; |
---|
| 550 | G4double fc = alzSquared*(0.202059-alzSquared* |
---|
| 551 | (0.03693-alzSquared* |
---|
| 552 | (0.00835-alzSquared*(0.00201-alzSquared* |
---|
| 553 | (0.00049-alzSquared* |
---|
| 554 | (0.00012-alzSquared*0.00003))))) |
---|
| 555 | +1.0/(alzSquared+1.0)); |
---|
| 556 | // |
---|
| 557 | // 3) Screening functions and low-energy corrections |
---|
| 558 | // |
---|
| 559 | G4double matRadius = 2.0/ fAtomicScreeningRadius[intZ-1]; |
---|
| 560 | if (fMaterialInvScreeningRadius) |
---|
| 561 | fMaterialInvScreeningRadius->insert(std::make_pair(material,matRadius)); |
---|
| 562 | |
---|
| 563 | std::pair<G4double,G4double> myPair(0,0); |
---|
[1337] | 564 | G4double f0a = 4.0*std::log(fAtomicScreeningRadius[intZ-1]); |
---|
[1316] | 565 | G4double f0b = f0a - 4.0*fc; |
---|
| 566 | myPair.first = f0a; |
---|
| 567 | myPair.second = f0b; |
---|
| 568 | |
---|
| 569 | if (fScreeningFunction) |
---|
| 570 | fScreeningFunction->insert(std::make_pair(material,myPair)); |
---|
| 571 | |
---|
| 572 | if (verboseLevel > 2) |
---|
| 573 | { |
---|
| 574 | G4cout << "Average Z for material " << material->GetName() << " = " << |
---|
| 575 | zeff << G4endl; |
---|
| 576 | G4cout << "Effective radius for material " << material->GetName() << " = " << |
---|
| 577 | fAtomicScreeningRadius[intZ-1] << " m_e*c/hbar --> BCB = " << |
---|
| 578 | matRadius << G4endl; |
---|
| 579 | G4cout << "Screening parameters F0 for material " << material->GetName() << " = " << |
---|
| 580 | f0a << "," << f0b << G4endl; |
---|
| 581 | } |
---|
| 582 | return; |
---|
| 583 | } |
---|
| 584 | |
---|
| 585 | //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... |
---|
| 586 | |
---|
| 587 | std::pair<G4double,G4double> |
---|
| 588 | G4Penelope08GammaConversionModel::GetScreeningFunctions(G4double B) |
---|
| 589 | { |
---|
| 590 | // This is subroutine SCHIFF of Penelope |
---|
| 591 | // |
---|
| 592 | // Screening Functions F1(B) and F2(B) in the Bethe-Heitler differential cross |
---|
| 593 | // section for pair production |
---|
| 594 | // |
---|
| 595 | std::pair<G4double,G4double> result(0.,0.); |
---|
| 596 | G4double BSquared = B*B; |
---|
[1337] | 597 | G4double f1 = 2.0-2.0*std::log(1.0+BSquared); |
---|
[1316] | 598 | G4double f2 = f1 - 6.66666666e-1; // (-2/3) |
---|
| 599 | if (B < 1.0e-10) |
---|
| 600 | f1 = f1-twopi*B; |
---|
| 601 | else |
---|
| 602 | { |
---|
| 603 | G4double a0 = 4.0*B*std::atan(1./B); |
---|
| 604 | f1 = f1 - a0; |
---|
[1337] | 605 | f2 += 2.0*BSquared*(4.0-a0-3.0*std::log((1.0+BSquared)/BSquared)); |
---|
[1316] | 606 | } |
---|
| 607 | G4double g1 = 0.5*(3.0*f1-f2); |
---|
| 608 | G4double g2 = 0.25*(3.0*f1+f2); |
---|
| 609 | |
---|
| 610 | result.first = g1; |
---|
| 611 | result.second = g2; |
---|
| 612 | |
---|
| 613 | return result; |
---|
| 614 | } |
---|