source: trunk/source/processes/electromagnetic/lowenergy/src/G4PenelopePhotoElectricModel.cc @ 1192

Last change on this file since 1192 was 1192, checked in by garnier, 15 years ago

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26// $Id: G4PenelopePhotoElectricModel.cc,v 1.10 2009/10/23 09:29:24 pandola Exp $
27// GEANT4 tag $Name: emlowen-V09-02-64 $
28//
29// Author: Luciano Pandola
30//
31// History:
32// --------
33// 08 Oct 2008   L Pandola  Migration from process to model
34// 08 Jan 2009   L Pandola  Check shell index to avoid mismatch between
35//                          the Penelope cross section database and the
36//                          G4AtomicTransitionManager database. It suppresses
37//                          a warning from G4AtomicTransitionManager only.
38//                          Results are unchanged.
39// 25 Mar 2009   L Pandola  Small fix to avoid wrong energy-violation warnings
40// 17 Apr 2009   V Ivanchenko Cleanup initialisation and generation of secondaries:
41//                  - apply internal high-energy limit only in constructor
42//                  - do not apply low-energy limit (default is 0)
43//                  - do not apply production threshold on secondaries
44// 19 May 2009   L Pandola    Explicitely set to zero pointers deleted in
45//                            Initialise(), since they might be checked later on
46// 21 Oct 2009   L Pandola    Remove un-necessary fUseAtomicDeexcitation flag - now managed by
47//                            G4VEmModel::DeexcitationFlag()
48//
49
50#include "G4PenelopePhotoElectricModel.hh"
51#include "G4ParticleDefinition.hh"
52#include "G4MaterialCutsCouple.hh"
53#include "G4ProductionCutsTable.hh"
54#include "G4DynamicParticle.hh"
55#include "G4PhysicsTable.hh"
56#include "G4ElementTable.hh"
57#include "G4Element.hh"
58#include "G4CrossSectionHandler.hh"
59#include "G4AtomicTransitionManager.hh"
60#include "G4AtomicShell.hh"
61#include "G4Gamma.hh"
62#include "G4Electron.hh"
63
64//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
65
66
67G4PenelopePhotoElectricModel::G4PenelopePhotoElectricModel(const G4ParticleDefinition*,
68                                             const G4String& nam)
69  :G4VEmModel(nam),isInitialised(false),crossSectionHandler(0),
70   shellCrossSectionHandler(0)
71{
72  fIntrinsicLowEnergyLimit = 100.0*eV;
73  fIntrinsicHighEnergyLimit = 100.0*GeV;
74  //  SetLowEnergyLimit(fIntrinsicLowEnergyLimit);
75  SetHighEnergyLimit(fIntrinsicHighEnergyLimit);
76  //
77  //by default the model will inkove the atomic deexcitation
78  SetDeexcitationFlag(true); 
79
80  verboseLevel= 0;
81  // Verbosity scale:
82  // 0 = nothing
83  // 1 = warning for energy non-conservation
84  // 2 = details of energy budget
85  // 3 = calculation of cross sections, file openings, sampling of atoms
86  // 4 = entering in methods
87}
88
89//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
90
91G4PenelopePhotoElectricModel::~G4PenelopePhotoElectricModel()
92{ 
93  if (crossSectionHandler) delete crossSectionHandler;
94  if (shellCrossSectionHandler) delete shellCrossSectionHandler;
95}
96
97//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
98
99void G4PenelopePhotoElectricModel::Initialise(const G4ParticleDefinition*,
100                                       const G4DataVector& )
101{
102  if (verboseLevel > 3)
103    G4cout << "Calling  G4PenelopePhotoElectricModel::Initialise()" << G4endl;
104  if (crossSectionHandler)
105    {
106      crossSectionHandler->Clear();
107      delete crossSectionHandler;
108      crossSectionHandler = 0;
109    }
110  if (shellCrossSectionHandler)
111    {
112      shellCrossSectionHandler->Clear();
113      delete shellCrossSectionHandler;
114      shellCrossSectionHandler =0;
115    }
116
117  //Re-initialize cross section handlers
118  crossSectionHandler = new G4CrossSectionHandler();
119  crossSectionHandler->Clear();
120  G4String crossSectionFile = "penelope/ph-cs-pen-";
121  crossSectionHandler->LoadData(crossSectionFile);
122  shellCrossSectionHandler = new G4CrossSectionHandler();
123  shellCrossSectionHandler->Clear();
124  crossSectionFile = "penelope/ph-ss-cs-pen-";
125  shellCrossSectionHandler->LoadShellData(crossSectionFile);
126  //This is used to retrieve cross section values later on
127  crossSectionHandler->BuildMeanFreePathForMaterials();
128
129  if (verboseLevel > 2) 
130    G4cout << "Loaded cross section files for PenelopePhotoElectric" << G4endl;
131
132  if (verboseLevel > 0) { 
133    G4cout << "Penelope Photo-Electric model is initialized " << G4endl
134           << "Energy range: "
135           << LowEnergyLimit() / MeV << " MeV - "
136           << HighEnergyLimit() / GeV << " GeV"
137           << G4endl;
138  }
139
140  if(isInitialised) return;
141  fParticleChange = GetParticleChangeForGamma();
142  isInitialised = true;
143}
144
145//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
146
147G4double G4PenelopePhotoElectricModel::ComputeCrossSectionPerAtom(
148                                       const G4ParticleDefinition*,
149                                             G4double energy,
150                                             G4double Z, G4double,
151                                             G4double, G4double)
152{
153  //
154  // Penelope model. Use data-driven approach for cross section estimate (and
155  // also shell sampling from a given atom). Data are from the Livermore database
156  //  D.E. Cullen et al., Report UCRL-50400 (1989)
157  //
158
159  if (verboseLevel > 3)
160    G4cout << "Calling ComputeCrossSectionPerAtom() of G4PenelopePhotoElectricModel" << G4endl;
161
162  G4int iZ = (G4int) Z;
163  //  if (!crossSectionHandler) // VI: should not be
164  //  {
165  //    G4cout << "G4PenelopePhotoElectricModel::ComputeCrossSectionPerAtom" << G4endl;
166  //    G4cout << "The cross section handler is not correctly initialized" << G4endl;
167  //    G4Exception();
168  //  }
169  G4double cs = crossSectionHandler->FindValue(iZ,energy);
170 
171  if (verboseLevel > 2)
172    G4cout << "Photoelectric cross section at " << energy/MeV << " MeV for Z=" << Z <<
173      " = " << cs/barn << " barn" << G4endl;
174  return cs;
175}
176
177//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
178
179void G4PenelopePhotoElectricModel::SampleSecondaries(std::vector<G4DynamicParticle*>* fvect,
180                                              const G4MaterialCutsCouple* couple,
181                                              const G4DynamicParticle* aDynamicGamma,
182                                              G4double,
183                                              G4double)
184{
185  //
186  // Photoelectric effect, Penelope model
187  //
188  // The target atom and the target shell are sampled according to the Livermore
189  // database
190  //  D.E. Cullen et al., Report UCRL-50400 (1989)
191  // The angular distribution of the electron in the final state is sampled
192  // according to the Sauter distribution from
193  //  F. Sauter, Ann. Phys. 11 (1931) 454
194  // The energy of the final electron is given by the initial photon energy minus
195  // the binding energy. Fluorescence de-excitation is subsequently produced
196  // (to fill the vacancy) according to the general Geant4 G4DeexcitationManager:
197  //  J. Stepanek, Comp. Phys. Comm. 1206 pp 1-1-9 (1997)
198
199  if (verboseLevel > 3)
200    G4cout << "Calling SamplingSecondaries() of G4PenelopePhotoElectricModel" << G4endl;
201
202  G4double photonEnergy = aDynamicGamma->GetKineticEnergy();
203
204  // always kill primary
205  fParticleChange->ProposeTrackStatus(fStopAndKill);
206  fParticleChange->SetProposedKineticEnergy(0.);
207
208  if (photonEnergy <= fIntrinsicLowEnergyLimit)
209    {
210      fParticleChange->ProposeLocalEnergyDeposit(photonEnergy);
211      return ;
212    }
213
214  G4ParticleMomentum photonDirection = aDynamicGamma->GetMomentumDirection();
215
216  // Select randomly one element in the current material
217  if (verboseLevel > 2)
218    G4cout << "Going to select element in " << couple->GetMaterial()->GetName() << G4endl;
219  //use crossSectionHandler instead of G4EmElementSelector because in this case
220  //the dimension of the table is equal to the dimension of the database
221  //(less interpolation errors)
222  G4int Z = crossSectionHandler->SelectRandomAtom(couple,photonEnergy);
223  if (verboseLevel > 2)
224    G4cout << "Selected Z = " << Z << G4endl;
225
226  // Select the ionised shell in the current atom according to shell cross sections
227  size_t shellIndex = shellCrossSectionHandler->SelectRandomShell(Z,photonEnergy);
228
229  // Retrieve the corresponding identifier and binding energy of the selected shell
230  const G4AtomicTransitionManager* transitionManager = G4AtomicTransitionManager::Instance();
231
232  //The number of shell cross section possibly reported in the Penelope database
233  //might be different from the number of shells in the G4AtomicTransitionManager
234  //(namely, Penelope may contain more shell, especially for very light elements).
235  //In order to avoid a warning message from the G4AtomicTransitionManager, I
236  //add this protection. Results are anyway changed, because when G4AtomicTransitionManager
237  //has a shellID>maxID, it sets the shellID to the last valid shell.
238  size_t numberOfShells = (size_t) transitionManager->NumberOfShells(Z);
239  if (shellIndex >= numberOfShells)
240    shellIndex = numberOfShells-1;
241
242  const G4AtomicShell* shell = transitionManager->Shell(Z,shellIndex);
243  G4double bindingEnergy = shell->BindingEnergy();
244  G4int shellId = shell->ShellId();
245
246  G4double localEnergyDeposit = 0.0;
247
248  // Primary outcoming electron
249  G4double eKineticEnergy = photonEnergy - bindingEnergy;
250 
251  // There may be cases where the binding energy of the selected shell is > photon energy
252  // In such cases do not generate secondaries
253  if (eKineticEnergy > 0.)
254    {
255      //Now check if the electron is above cuts: if so, it is created explicitely
256      //VI: checking cut here provides inconsistency in testing
257      //      if (eKineticEnergy > cutE)
258      // The electron is created
259      // Direction sampled from the Sauter distribution
260      G4double cosTheta = SampleElectronDirection(eKineticEnergy);
261      G4double sinTheta = std::sqrt(1-cosTheta*cosTheta);
262      G4double phi = twopi * G4UniformRand() ;
263      G4double dirx = sinTheta * std::cos(phi);
264      G4double diry = sinTheta * std::sin(phi);
265      G4double dirz = cosTheta ;
266      G4ThreeVector electronDirection(dirx,diry,dirz); //electron direction
267      electronDirection.rotateUz(photonDirection);
268      G4DynamicParticle* electron = new G4DynamicParticle (G4Electron::Electron(), 
269                                                           electronDirection, 
270                                                           eKineticEnergy);
271      fvect->push_back(electron);
272    } 
273  //  else
274  //  {
275  //    localEnergyDeposit += eKineticEnergy;   
276  //    eKineticEnergy = 0;
277  //  }
278  //  }
279  else
280    {
281      bindingEnergy = photonEnergy;
282    }
283  G4double energyInFluorescence = 0; //testing purposes
284
285  //Now, take care of fluorescence, if required
286  if(DeexcitationFlag() && Z > 5) 
287    {
288      const G4ProductionCutsTable* theCoupleTable=
289        G4ProductionCutsTable::GetProductionCutsTable();
290      size_t indx = couple->GetIndex();
291      G4double cutG = (*(theCoupleTable->GetEnergyCutsVector(0)))[indx];
292      G4double cutE = (*(theCoupleTable->GetEnergyCutsVector(1)))[indx];
293     
294      // Protection to avoid generating photons in the unphysical case of
295      // shell binding energy > photon energy
296      if (bindingEnergy > cutG || bindingEnergy > cutE)
297        {
298          deexcitationManager.SetCutForSecondaryPhotons(cutG);
299          deexcitationManager.SetCutForAugerElectrons(cutE);
300          std::vector<G4DynamicParticle*>* photonVector = 
301            deexcitationManager.GenerateParticles(Z,shellId); 
302          //Check for secondaries
303          if(photonVector) 
304            {
305              for (size_t k=0; k< photonVector->size(); k++)
306                {
307                  G4DynamicParticle* aPhoton = (*photonVector)[k];
308                  if (aPhoton)
309                    {
310                      G4double itsEnergy = aPhoton->GetKineticEnergy();
311                      if (itsEnergy <= bindingEnergy)
312                        {
313                          if(aPhoton->GetDefinition() == G4Gamma::Gamma())
314                            energyInFluorescence += itsEnergy;
315                          bindingEnergy -= itsEnergy;
316                          fvect->push_back(aPhoton);
317                        }
318                      else
319                        {
320                          delete aPhoton;
321                          (*photonVector)[k] = 0;
322                        }
323                    }
324                }
325              delete photonVector;
326            }
327        }
328    }
329  //Residual energy is deposited locally
330  localEnergyDeposit += bindingEnergy;
331     
332  if (localEnergyDeposit < 0)
333    {
334      G4cout << "WARNING - "
335             << "G4PenelopePhotoElectric::PostStepDoIt - Negative energy deposit"
336             << G4endl;
337      localEnergyDeposit = 0;
338    }
339
340  fParticleChange->ProposeLocalEnergyDeposit(localEnergyDeposit);
341
342  if (verboseLevel > 1)
343    {
344      G4cout << "-----------------------------------------------------------" << G4endl;
345      G4cout << "Energy balance from G4PenelopePhotoElectric" << G4endl;
346      G4cout << "Incoming photon energy: " << photonEnergy/keV << " keV" << G4endl;
347      G4cout << "-----------------------------------------------------------" << G4endl;
348      if (eKineticEnergy)
349        G4cout << "Outgoing electron " << eKineticEnergy/keV << " keV" << G4endl;
350      G4cout << "Fluorescence: " << energyInFluorescence/keV << " keV" << G4endl;
351      G4cout << "Local energy deposit " << localEnergyDeposit/keV << " keV" << G4endl;
352      G4cout << "Total final state: " << (eKineticEnergy+energyInFluorescence+localEnergyDeposit)/keV << 
353        " keV" << G4endl;
354      G4cout << "-----------------------------------------------------------" << G4endl;
355    }
356  if (verboseLevel > 0)
357    {
358      G4double energyDiff = 
359        std::fabs(eKineticEnergy+energyInFluorescence+localEnergyDeposit-photonEnergy);
360      if (energyDiff > 0.05*keV)
361        G4cout << "Warning from G4PenelopePhotoElectric: problem with energy conservation: " << 
362          (eKineticEnergy+energyInFluorescence+localEnergyDeposit)/keV
363               << " keV (final) vs. " << 
364          photonEnergy/keV << " keV (initial)" << G4endl;
365    }
366}
367
368//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
369
370void G4PenelopePhotoElectricModel::ActivateAuger(G4bool augerbool)
371{
372  if (!DeexcitationFlag() && augerbool)
373    {
374      G4cout << "WARNING - G4PenelopePhotoElectricModel" << G4endl;
375      G4cout << "The use of the Atomic Deexcitation Manager is set to false " << G4endl;
376      G4cout << "Therefore, Auger electrons will be not generated anyway" << G4endl;
377    }
378  deexcitationManager.ActivateAugerElectronProduction(augerbool);
379  if (verboseLevel > 1)
380    G4cout << "Auger production set to " << augerbool << G4endl;
381}
382
383//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
384
385G4double G4PenelopePhotoElectricModel::SampleElectronDirection(G4double energy)
386{
387  G4double costheta = 1.0;
388  if (energy>1*GeV) return costheta;
389 
390  //1) initialize energy-dependent variables
391  // Variable naming according to Eq. (2.24) of Penelope Manual
392  // (pag. 44)
393  G4double gamma = 1.0 + energy/electron_mass_c2;
394  G4double gamma2 = gamma*gamma;
395  G4double beta = std::sqrt((gamma2-1.0)/gamma2);
396   
397  // ac corresponds to "A" of Eq. (2.31)
398  //
399  G4double ac = (1.0/beta) - 1.0;
400  G4double a1 = 0.5*beta*gamma*(gamma-1.0)*(gamma-2.0);
401  G4double a2 = ac + 2.0;
402  G4double gtmax = 2.0*(a1 + 1.0/ac);
403 
404  G4double tsam = 0;
405  G4double gtr = 0;
406
407  //2) sampling. Eq. (2.31) of Penelope Manual
408  // tsam = 1-std::cos(theta)
409  // gtr = rejection function according to Eq. (2.28)
410  do{
411    G4double rand = G4UniformRand();
412    tsam = 2.0*ac * (2.0*rand + a2*std::sqrt(rand)) / (a2*a2 - 4.0*rand);
413    gtr = (2.0 - tsam) * (a1 + 1.0/(ac+tsam));
414  }while(G4UniformRand()*gtmax > gtr);
415  costheta = 1.0-tsam;
416  return costheta;
417}
418
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