source: trunk/source/processes/electromagnetic/lowenergy/src/G4PenelopePhotoElectricModel.cc@ 1197

Last change on this file since 1197 was 1196, checked in by garnier, 16 years ago

update CVS release candidate geant4.9.3.01
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25//
26// $Id: G4PenelopePhotoElectricModel.cc,v 1.10 2009/10/23 09:29:24 pandola Exp $
27// GEANT4 tag $Name: geant4-09-03-cand-01 $
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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