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25//
26// $Id: G4PAIModel.cc,v 1.54 2010/11/04 17:30:32 vnivanch Exp $
27// GEANT4 tag $Name: emstand-V09-03-25 $
28//
29// -------------------------------------------------------------------
30//
31// GEANT4 Class
32// File name:     G4PAIModel.cc
33//
34// Author: Vladimir.Grichine@cern.ch on base of Vladimir Ivanchenko model interface
35//
36// Creation date: 05.10.2003
37//
38// Modifications:
39//
40// 17.08.04 V.Grichine, bug fixed for Tkin<=0 in SampleSecondary
41// 16.08.04 V.Grichine, bug fixed in massRatio for DEDX, CrossSection, SampleSecondary
42// 08.04.05 Major optimisation of internal interfaces (V.Ivantchenko)
43// 26.07.09 Fixed logic to work with several materials (V.Ivantchenko)
44//
45
46#include "G4Region.hh"
47#include "G4PhysicsLogVector.hh"
48#include "G4PhysicsFreeVector.hh"
49#include "G4PhysicsTable.hh"
50#include "G4ProductionCutsTable.hh"
51#include "G4MaterialCutsCouple.hh"
52#include "G4MaterialTable.hh"
53#include "G4SandiaTable.hh"
54#include "G4OrderedTable.hh"
55
56#include "G4PAIModel.hh"
57#include "Randomize.hh"
58#include "G4Electron.hh"
59#include "G4Positron.hh"
60#include "G4Poisson.hh"
61#include "G4Step.hh"
62#include "G4Material.hh"
63#include "G4DynamicParticle.hh"
64#include "G4ParticleDefinition.hh"
65#include "G4ParticleChangeForLoss.hh"
66
67////////////////////////////////////////////////////////////////////////
68
69using namespace std;
70
71G4PAIModel::G4PAIModel(const G4ParticleDefinition* p, const G4String& nam)
72  : G4VEmModel(nam),G4VEmFluctuationModel(nam),
73  fVerbose(0),
74  fLowestGamma(1.005),
75  fHighestGamma(10000.),
76  fTotBin(200),
77  fMeanNumber(20),
78  fParticle(0),
79  fHighKinEnergy(100.*TeV),
80  fTwoln10(2.0*log(10.0)),
81  fBg2lim(0.0169),
82  fTaulim(8.4146e-3)
83{ 
84  fElectron = G4Electron::Electron();
85  fPositron = G4Positron::Positron();
86
87  fPAItransferTable  = 0;
88  fPAIdEdxTable      = 0;
89  fSandiaPhotoAbsCof = 0;
90  fdEdxVector        = 0;
91  fLambdaVector      = 0;
92  fdNdxCutVector     = 0;
93  fParticleEnergyVector = 0;
94  fSandiaIntervalNumber = 0;
95  fMatIndex = 0;
96  fDeltaCutInKinEnergy = 0.0;
97
98  if(p) { SetParticle(p); }
99  else  { SetParticle(fElectron); }
100
101  isInitialised      = false;
102}
103
104////////////////////////////////////////////////////////////////////////////
105
106G4PAIModel::~G4PAIModel()
107{
108  //  G4cout << "PAI: start destruction" << G4endl;
109  if(fParticleEnergyVector) delete fParticleEnergyVector;
110  if(fdEdxVector)           delete fdEdxVector ;
111  if(fLambdaVector)         delete fLambdaVector;
112  if(fdNdxCutVector)        delete fdNdxCutVector;
113
114  if( fPAItransferTable )
115    {
116      fPAItransferTable->clearAndDestroy();
117      delete fPAItransferTable ;
118    }
119  if( fPAIdEdxTable )
120    {
121      fPAIdEdxTable->clearAndDestroy();
122      delete fPAIdEdxTable ;
123    }
124  if(fSandiaPhotoAbsCof)
125    {
126      for(G4int i=0;i<fSandiaIntervalNumber;i++)
127        {
128          delete[] fSandiaPhotoAbsCof[i];
129        }
130      delete[] fSandiaPhotoAbsCof;
131    }
132  //G4cout << "PAI: end destruction" << G4endl;
133}
134
135///////////////////////////////////////////////////////////////////////////////
136
137void G4PAIModel::SetParticle(const G4ParticleDefinition* p)
138{
139  if(fParticle == p) { return; }
140  fParticle = p;
141  fMass = fParticle->GetPDGMass();
142  fSpin = fParticle->GetPDGSpin();
143  G4double q = fParticle->GetPDGCharge()/eplus;
144  fChargeSquare = q*q;
145  fLowKinEnergy = 0.2*MeV*fMass/proton_mass_c2;
146  fRatio = electron_mass_c2/fMass;
147  fQc = fMass/fRatio;
148  fLowestKineticEnergy  = fMass*(fLowestGamma  - 1.0);
149  fHighestKineticEnergy = fMass*(fHighestGamma - 1.0);
150}
151
152////////////////////////////////////////////////////////////////////////////
153
154void G4PAIModel::Initialise(const G4ParticleDefinition* p,
155                            const G4DataVector&)
156{
157  //G4cout<<"G4PAIModel::Initialise for "<<p->GetParticleName()<<G4endl;
158  if(isInitialised) { return; }
159  isInitialised = true;
160
161  SetParticle(p);
162
163  fParticleEnergyVector = new G4PhysicsLogVector(fLowestKineticEnergy,
164                                                 fHighestKineticEnergy,
165                                                 fTotBin);
166
167  fParticleChange = GetParticleChangeForLoss();
168
169  // Prepare initialization
170  const G4ProductionCutsTable* theCoupleTable =
171        G4ProductionCutsTable::GetProductionCutsTable();
172  const G4MaterialTable* theMaterialTable = G4Material::GetMaterialTable();
173  size_t numOfMat   = G4Material::GetNumberOfMaterials();
174  size_t numRegions = fPAIRegionVector.size();
175
176  for(size_t iReg = 0; iReg < numRegions; ++iReg) // region loop
177  {
178    const G4Region* curReg = fPAIRegionVector[iReg];
179    for(size_t jMat = 0; jMat < numOfMat; ++jMat) // region material loop
180    {
181      fMaterial  = (*theMaterialTable)[jMat];
182      fCutCouple = theCoupleTable->GetMaterialCutsCouple( fMaterial, 
183                                          curReg->GetProductionCuts() );
184      //G4cout << "Reg <" <<curReg->GetName() << ">  mat <"
185      //             << fMaterial->GetName() << ">  fCouple= "
186      //             << fCutCouple<<"  " << p->GetParticleName() <<G4endl;
187      if( fCutCouple ) {
188        fMaterialCutsCoupleVector.push_back(fCutCouple);
189
190        fPAItransferTable = new G4PhysicsTable(fTotBin+1);
191        fPAIdEdxTable = new G4PhysicsTable(fTotBin+1);
192
193        fDeltaCutInKinEnergy = 
194          (*theCoupleTable->GetEnergyCutsVector(1))[fCutCouple->GetIndex()];
195     
196        //ComputeSandiaPhotoAbsCof();
197        BuildPAIonisationTable();
198
199        fPAIxscBank.push_back(fPAItransferTable);
200        fPAIdEdxBank.push_back(fPAIdEdxTable);
201        fdEdxTable.push_back(fdEdxVector);
202
203        BuildLambdaVector();
204        fdNdxCutTable.push_back(fdNdxCutVector);
205        fLambdaTable.push_back(fLambdaVector);
206      }
207    }
208  }
209}
210
211//////////////////////////////////////////////////////////////////
212
213void G4PAIModel::InitialiseMe(const G4ParticleDefinition*) 
214{}
215
216//////////////////////////////////////////////////////////////////
217
218void G4PAIModel::ComputeSandiaPhotoAbsCof()
219{ 
220  G4int i, j;
221  const G4MaterialTable* theMaterialTable = G4Material::GetMaterialTable();
222
223  G4SandiaTable thisMaterialSandiaTable(fMatIndex) ;
224  G4int numberOfElements = 
225    (*theMaterialTable)[fMatIndex]->GetNumberOfElements();
226
227  G4int* thisMaterialZ = new G4int[numberOfElements] ;
228
229  for(i=0;i<numberOfElements;i++) 
230  {
231    thisMaterialZ[i] = 
232    (G4int)(*theMaterialTable)[fMatIndex]->GetElement(i)->GetZ() ;
233  } 
234  fSandiaIntervalNumber = thisMaterialSandiaTable.SandiaIntervals
235                           (thisMaterialZ,numberOfElements) ;
236
237  fSandiaIntervalNumber = thisMaterialSandiaTable.SandiaMixing
238                           ( thisMaterialZ ,
239                             (*theMaterialTable)[fMatIndex]->GetFractionVector() ,
240                             numberOfElements,fSandiaIntervalNumber) ;
241   
242  fSandiaPhotoAbsCof = new G4double*[fSandiaIntervalNumber] ;
243
244  for(i=0; i<fSandiaIntervalNumber; i++) 
245  {
246    fSandiaPhotoAbsCof[i] = new G4double[5];
247  }
248   
249  for( i = 0 ; i < fSandiaIntervalNumber ; i++ )
250  {
251    fSandiaPhotoAbsCof[i][0] = thisMaterialSandiaTable.GetPhotoAbsorpCof(i+1,0); 
252
253    for( j = 1; j < 5 ; j++ )
254    {
255      fSandiaPhotoAbsCof[i][j] = thisMaterialSandiaTable.GetPhotoAbsorpCof(i+1,j)*
256                 (*theMaterialTable)[fMatIndex]->GetDensity() ;
257    }
258  }
259  delete[] thisMaterialZ;
260}
261
262////////////////////////////////////////////////////////////////////////////
263//
264// Build tables for the ionization energy loss
265//  the tables are built for MATERIALS
266//                           *********
267
268void G4PAIModel::BuildPAIonisationTable()
269{
270  G4double LowEdgeEnergy , ionloss ;
271  G4double tau, Tmax, Tmin, Tkin, deltaLow, gamma, bg2 ;
272
273  fdEdxVector = new G4PhysicsLogVector( fLowestKineticEnergy,
274                                        fHighestKineticEnergy,
275                                        fTotBin);
276  G4SandiaTable* sandia = fMaterial->GetSandiaTable();
277
278  Tmin = sandia->GetSandiaCofForMaterialPAI(0,0)*keV;
279  deltaLow = 100.*eV; // 0.5*eV ;
280
281  for (G4int i = 0 ; i <= fTotBin ; i++)  //The loop for the kinetic energy
282  {
283    LowEdgeEnergy = fParticleEnergyVector->GetLowEdgeEnergy(i) ;
284    tau = LowEdgeEnergy/fMass ;
285    gamma = tau +1. ;
286    // G4cout<<"gamma = "<<gamma<<endl ;
287    bg2 = tau*( tau + 2. );
288    Tmax = MaxSecondaryEnergy(fParticle, LowEdgeEnergy); 
289    //    Tmax = std::min(fDeltaCutInKinEnergy, Tmax);
290    Tkin = Tmax ;
291
292    if ( Tmax < Tmin + deltaLow )  // low energy safety
293      Tkin = Tmin + deltaLow ;
294
295    fPAIySection.Initialize(fMaterial, Tkin, bg2);
296
297    // G4cout<<"ionloss = "<<ionloss*cm/keV<<" keV/cm"<<endl ;
298    // G4cout<<"n1 = "<<protonPAI.GetIntegralPAIxSection(1)*cm<<" 1/cm"<<endl ;
299    // G4cout<<"protonPAI.GetSplineSize() = "<<
300    //    protonPAI.GetSplineSize()<<G4endl<<G4endl ;
301
302    G4int n = fPAIySection.GetSplineSize();
303    G4PhysicsFreeVector* transferVector = new G4PhysicsFreeVector(n) ;
304    G4PhysicsFreeVector* dEdxVector = new G4PhysicsFreeVector(n);
305
306    for( G4int k = 0 ; k < n; k++ )
307    {
308      transferVector->PutValue( k ,
309                                fPAIySection.GetSplineEnergy(k+1),
310                                fPAIySection.GetIntegralPAIySection(k+1) ) ;
311      dEdxVector->PutValue( k ,
312                                fPAIySection.GetSplineEnergy(k+1),
313                                fPAIySection.GetIntegralPAIdEdx(k+1) ) ;
314    }
315    ionloss = fPAIySection.GetMeanEnergyLoss() ;   //  total <dE/dx>
316
317    if ( ionloss < DBL_MIN) { ionloss = 0.0; }
318    fdEdxVector->PutValue(i,ionloss) ;
319
320    fPAItransferTable->insertAt(i,transferVector) ;
321    fPAIdEdxTable->insertAt(i,dEdxVector) ;
322
323  }                                        // end of Tkin loop
324}
325
326///////////////////////////////////////////////////////////////////////
327//
328// Build mean free path tables for the delta ray production process
329//     tables are built for MATERIALS
330//
331
332void G4PAIModel::BuildLambdaVector()
333{
334  fLambdaVector = new G4PhysicsLogVector( fLowestKineticEnergy,
335                                          fHighestKineticEnergy,
336                                          fTotBin                ) ;
337  fdNdxCutVector = new G4PhysicsLogVector( fLowestKineticEnergy,
338                                          fHighestKineticEnergy,
339                                          fTotBin                ) ;
340  if(fVerbose > 1)
341  {
342    G4cout<<"PAIModel DeltaCutInKineticEnergyNow = "
343          <<fDeltaCutInKinEnergy/keV<<" keV"<<G4endl;
344  }
345  for (G4int i = 0 ; i <= fTotBin ; i++ )
346  {
347    G4double dNdxCut = GetdNdxCut(i,fDeltaCutInKinEnergy) ;
348    //G4cout << "i= " << i << " x= " << dNdxCut << G4endl;
349    if(dNdxCut < 0.0) dNdxCut = 0.0; 
350    //    G4double lambda = dNdxCut <= DBL_MIN ? DBL_MAX: 1.0/dNdxCut ;
351    G4double lambda = DBL_MAX;
352    if(dNdxCut > 0.0) lambda = 1.0/dNdxCut;
353
354    fLambdaVector->PutValue(i, lambda) ;
355    fdNdxCutVector->PutValue(i, dNdxCut) ;
356  }
357}
358
359///////////////////////////////////////////////////////////////////////
360//
361// Returns integral PAI cross section for energy transfers >= transferCut
362
363G4double 
364G4PAIModel::GetdNdxCut( G4int iPlace, G4double transferCut)
365{ 
366  G4int iTransfer;
367  G4double x1, x2, y1, y2, dNdxCut;
368  // G4cout<<"iPlace = "<<iPlace<<"; "<<"transferCut = "<<transferCut<<G4endl;
369  // G4cout<<"size = "<<G4int((*fPAItransferTable)(iPlace)->GetVectorLength())
370  //           <<G4endl; 
371  for( iTransfer = 0 ; 
372       iTransfer < G4int((*fPAItransferTable)(iPlace)->GetVectorLength()) ; 
373       iTransfer++)
374  {
375    if(transferCut <= (*fPAItransferTable)(iPlace)->GetLowEdgeEnergy(iTransfer))
376    {
377      break ;
378    }
379  } 
380  if ( iTransfer >= G4int((*fPAItransferTable)(iPlace)->GetVectorLength()) )
381  {
382      iTransfer = (*fPAItransferTable)(iPlace)->GetVectorLength() - 1 ;
383  }
384  y1 = (*(*fPAItransferTable)(iPlace))(iTransfer-1) ;
385  y2 = (*(*fPAItransferTable)(iPlace))(iTransfer) ;
386  if(y1 < 0.0) y1 = 0.0;
387  if(y2 < 0.0) y2 = 0.0;
388  // G4cout<<"y1 = "<<y1<<"; "<<"y2 = "<<y2<<G4endl;
389  x1 = (*fPAItransferTable)(iPlace)->GetLowEdgeEnergy(iTransfer-1) ;
390  x2 = (*fPAItransferTable)(iPlace)->GetLowEdgeEnergy(iTransfer) ;
391  // G4cout<<"x1 = "<<x1<<"; "<<"x2 = "<<x2<<G4endl;
392
393  if ( y1 == y2 )    dNdxCut = y2 ;
394  else
395  {
396    //  if ( x1 == x2  ) dNdxCut = y1 + (y2 - y1)*G4UniformRand() ;
397    //    if ( std::abs(x1-x2) <= eV  ) dNdxCut = y1 + (y2 - y1)*G4UniformRand() ;
398    if ( std::abs(x1-x2) <= eV  ) dNdxCut = y1 + (y2 - y1)*0.5 ;
399    else             dNdxCut = y1 + (transferCut - x1)*(y2 - y1)/(x2 - x1) ;     
400  }
401  //  G4cout<<""<<dNdxCut<<G4endl;
402  if(dNdxCut < 0.0) dNdxCut = 0.0; 
403  return dNdxCut ;
404}
405///////////////////////////////////////////////////////////////////////
406//
407// Returns integral dEdx for energy transfers >= transferCut
408
409G4double 
410G4PAIModel::GetdEdxCut( G4int iPlace, G4double transferCut)
411{ 
412  G4int iTransfer;
413  G4double x1, x2, y1, y2, dEdxCut;
414  //G4cout<<"iPlace = "<<iPlace<<"; "<<"transferCut = "<<transferCut<<G4endl;
415  // G4cout<<"size = "<<G4int((*fPAIdEdxTable)(iPlace)->GetVectorLength())
416  //           <<G4endl; 
417  for( iTransfer = 0 ; 
418       iTransfer < G4int((*fPAIdEdxTable)(iPlace)->GetVectorLength()) ; 
419       iTransfer++)
420  {
421    if(transferCut <= (*fPAIdEdxTable)(iPlace)->GetLowEdgeEnergy(iTransfer))
422    {
423      break ;
424    }
425  } 
426  if ( iTransfer >= G4int((*fPAIdEdxTable)(iPlace)->GetVectorLength()) )
427  {
428      iTransfer = (*fPAIdEdxTable)(iPlace)->GetVectorLength() - 1 ;
429  }
430  y1 = (*(*fPAIdEdxTable)(iPlace))(iTransfer-1) ;
431  y2 = (*(*fPAIdEdxTable)(iPlace))(iTransfer) ;
432  if(y1 < 0.0) y1 = 0.0;
433  if(y2 < 0.0) y2 = 0.0;
434  //G4cout<<"y1 = "<<y1<<"; "<<"y2 = "<<y2<<G4endl;
435  x1 = (*fPAIdEdxTable)(iPlace)->GetLowEdgeEnergy(iTransfer-1) ;
436  x2 = (*fPAIdEdxTable)(iPlace)->GetLowEdgeEnergy(iTransfer) ;
437  //G4cout<<"x1 = "<<x1<<"; "<<"x2 = "<<x2<<G4endl;
438
439  if ( y1 == y2 )    dEdxCut = y2 ;
440  else
441  {
442    //  if ( x1 == x2  ) dEdxCut = y1 + (y2 - y1)*G4UniformRand() ;
443    //    if ( std::abs(x1-x2) <= eV  ) dEdxCut = y1 + (y2 - y1)*G4UniformRand() ;
444    if ( std::abs(x1-x2) <= eV  ) dEdxCut = y1 + (y2 - y1)*0.5 ;
445    else             dEdxCut = y1 + (transferCut - x1)*(y2 - y1)/(x2 - x1) ;     
446  }
447  //G4cout<<""<<dEdxCut<<G4endl;
448  if(dEdxCut < 0.0) dEdxCut = 0.0; 
449  return dEdxCut ;
450}
451
452//////////////////////////////////////////////////////////////////////////////
453
454G4double G4PAIModel::ComputeDEDXPerVolume(const G4Material*,
455                                          const G4ParticleDefinition* p,
456                                          G4double kineticEnergy,
457                                          G4double cutEnergy)
458{
459  G4int iTkin,iPlace;
460 
461  //G4double cut = std::min(MaxSecondaryEnergy(p, kineticEnergy), cutEnergy);
462  G4double cut = cutEnergy;
463
464  G4double massRatio  = fMass/p->GetPDGMass();
465  G4double scaledTkin = kineticEnergy*massRatio;
466  G4double charge     = p->GetPDGCharge();
467  G4double charge2    = charge*charge;
468  const G4MaterialCutsCouple* matCC = CurrentCouple();
469
470  size_t jMat = 0;
471  for(;jMat < fMaterialCutsCoupleVector.size(); ++jMat )
472  {
473    if( matCC == fMaterialCutsCoupleVector[jMat] ) break;
474  }
475  //G4cout << "jMat= " << jMat
476  //     << " jMax= " << fMaterialCutsCoupleVector.size()
477  //       << " matCC: " << matCC;
478  //if(matCC) G4cout << " mat: " << matCC->GetMaterial()->GetName();
479  //  G4cout << G4endl;
480  if(jMat == fMaterialCutsCoupleVector.size()) return 0.0;
481
482  fPAIdEdxTable = fPAIdEdxBank[jMat];
483  fdEdxVector = fdEdxTable[jMat];
484  for(iTkin = 0 ; iTkin <= fTotBin ; iTkin++)
485  {
486    if(scaledTkin < fParticleEnergyVector->GetLowEdgeEnergy(iTkin)) break ;   
487  }
488  //G4cout << "E= " << scaledTkin << " iTkin= " << iTkin
489  //     << "  " << fdEdxVector->GetVectorLength()<<G4endl;
490  iPlace = iTkin - 1;
491  if(iPlace < 0) iPlace = 0;
492  else if(iPlace >= fTotBin) iPlace = fTotBin-1;
493  G4double dEdx = charge2*( (*fdEdxVector)(iPlace) - GetdEdxCut(iPlace,cut) );
494  if( dEdx < 0.) dEdx = 0.;
495  return dEdx;
496}
497
498/////////////////////////////////////////////////////////////////////////
499
500G4double G4PAIModel::CrossSectionPerVolume( const G4Material*,
501                                            const G4ParticleDefinition* p,
502                                            G4double kineticEnergy,
503                                            G4double cutEnergy,
504                                            G4double maxEnergy  ) 
505{
506  G4int iTkin,iPlace;
507  G4double tmax = std::min(MaxSecondaryEnergy(p, kineticEnergy), maxEnergy);
508  if(tmax <= cutEnergy) return 0.0;
509  G4double massRatio  = fMass/p->GetPDGMass();
510  G4double scaledTkin = kineticEnergy*massRatio;
511  G4double charge     = p->GetPDGCharge();
512  G4double charge2    = charge*charge, cross, cross1, cross2;
513  const G4MaterialCutsCouple* matCC = CurrentCouple();
514
515  size_t jMat = 0;
516  for(;jMat < fMaterialCutsCoupleVector.size(); ++jMat )
517  {
518    if( matCC == fMaterialCutsCoupleVector[jMat] ) break;
519  }
520  if(jMat == fMaterialCutsCoupleVector.size()) return 0.0;
521
522  fPAItransferTable = fPAIxscBank[jMat];
523
524  for(iTkin = 0 ; iTkin <= fTotBin ; iTkin++)
525  {
526    if(scaledTkin < fParticleEnergyVector->GetLowEdgeEnergy(iTkin)) break ;   
527  }
528  iPlace = iTkin - 1;
529  if(iPlace < 0) iPlace = 0;
530  else if(iPlace >= fTotBin) iPlace = fTotBin-1; 
531
532  //G4cout<<"iPlace = "<<iPlace<<"; tmax = "
533  // <<tmax<<"; cutEnergy = "<<cutEnergy<<G4endl; 
534  cross1 = GetdNdxCut(iPlace,tmax) ;
535  //G4cout<<"cross1 = "<<cross1<<G4endl; 
536  cross2 = GetdNdxCut(iPlace,cutEnergy) ; 
537  //G4cout<<"cross2 = "<<cross2<<G4endl; 
538  cross  = (cross2-cross1)*charge2;
539  //G4cout<<"cross = "<<cross<<G4endl; 
540  if( cross < DBL_MIN) cross = 0.0;
541  //  if( cross2 < DBL_MIN) cross2 = DBL_MIN;
542
543  // return cross2;
544  return cross;
545}
546
547///////////////////////////////////////////////////////////////////////////
548//
549// It is analog of PostStepDoIt in terms of secondary electron.
550//
551 
552void G4PAIModel::SampleSecondaries(std::vector<G4DynamicParticle*>* vdp,
553                                   const G4MaterialCutsCouple* matCC,
554                                   const G4DynamicParticle* dp,
555                                   G4double tmin,
556                                   G4double maxEnergy)
557{
558  size_t jMat = 0;
559  for(;jMat < fMaterialCutsCoupleVector.size(); ++jMat )
560  {
561    if( matCC == fMaterialCutsCoupleVector[jMat] ) break;
562  }
563  if(jMat == fMaterialCutsCoupleVector.size()) return;
564
565  fPAItransferTable = fPAIxscBank[jMat];
566  fdNdxCutVector    = fdNdxCutTable[jMat];
567
568  G4double tmax = std::min(MaxSecondaryKinEnergy(dp), maxEnergy);
569  if( tmin >= tmax && fVerbose > 0)
570  {
571    G4cout<<"G4PAIModel::SampleSecondary: tmin >= tmax "<<G4endl;
572  }
573  G4ThreeVector direction= dp->GetMomentumDirection();
574  G4double particleMass  = dp->GetMass();
575  G4double kineticEnergy = dp->GetKineticEnergy();
576
577  G4double massRatio     = fMass/particleMass;
578  G4double scaledTkin    = kineticEnergy*massRatio;
579  G4double totalEnergy   = kineticEnergy + particleMass;
580  G4double pSquare       = kineticEnergy*(totalEnergy+particleMass);
581 
582  G4double deltaTkin     = GetPostStepTransfer(scaledTkin);
583
584  // G4cout<<"G4PAIModel::SampleSecondaries; deltaKIn = "<<deltaTkin/keV<<" keV "<<G4endl;
585
586  if( deltaTkin <= 0. && fVerbose > 0) 
587  {
588    G4cout<<"G4PAIModel::SampleSecondary e- deltaTkin = "<<deltaTkin<<G4endl;
589  }
590  if( deltaTkin <= 0.) return;
591
592  if( deltaTkin > tmax) deltaTkin = tmax;
593
594  G4double deltaTotalMomentum = sqrt(deltaTkin*(deltaTkin + 2. * electron_mass_c2 ));
595  G4double totalMomentum      = sqrt(pSquare);
596  G4double costheta           = deltaTkin*(totalEnergy + electron_mass_c2)
597                                /(deltaTotalMomentum * totalMomentum);
598
599  if( costheta > 0.99999 ) costheta = 0.99999;
600  G4double sintheta = 0.0;
601  G4double sin2 = 1. - costheta*costheta;
602  if( sin2 > 0.) sintheta = sqrt(sin2);
603
604  //  direction of the delta electron
605  G4double phi  = twopi*G4UniformRand(); 
606  G4double dirx = sintheta*cos(phi), diry = sintheta*sin(phi), dirz = costheta;
607
608  G4ThreeVector deltaDirection(dirx,diry,dirz);
609  deltaDirection.rotateUz(direction);
610  deltaDirection.unit();
611
612  // primary change
613  kineticEnergy -= deltaTkin;
614  G4ThreeVector dir = totalMomentum*direction - deltaTotalMomentum*deltaDirection;
615  direction = dir.unit();
616  fParticleChange->SetProposedKineticEnergy(kineticEnergy);
617  fParticleChange->SetProposedMomentumDirection(direction);
618
619  // create G4DynamicParticle object for e- delta ray
620  G4DynamicParticle* deltaRay = new G4DynamicParticle;
621  deltaRay->SetDefinition(G4Electron::Electron());
622  deltaRay->SetKineticEnergy( deltaTkin );  //  !!! trick for last steps /2.0 ???
623  deltaRay->SetMomentumDirection(deltaDirection); 
624
625  vdp->push_back(deltaRay);
626}
627
628
629///////////////////////////////////////////////////////////////////////
630//
631// Returns post step PAI energy transfer > cut electron energy according to passed
632// scaled kinetic energy of particle
633
634G4double 
635G4PAIModel::GetPostStepTransfer( G4double scaledTkin )
636{ 
637  // G4cout<<"G4PAIModel::GetPostStepTransfer"<<G4endl ;
638
639  G4int iTkin, iTransfer, iPlace  ;
640  G4double transfer = 0.0, position, dNdxCut1, dNdxCut2, E1, E2, W1, W2, W ;
641
642  for(iTkin=0;iTkin<=fTotBin;iTkin++)
643  {
644    if(scaledTkin < fParticleEnergyVector->GetLowEdgeEnergy(iTkin))  break ;
645  }
646  iPlace = iTkin - 1 ;
647  // G4cout<<"from search, iPlace = "<<iPlace<<G4endl ;
648  if(iPlace < 0) iPlace = 0;
649  else if(iPlace >= fTotBin) iPlace = fTotBin-1; 
650  dNdxCut1 = (*fdNdxCutVector)(iPlace) ; 
651  // G4cout<<"dNdxCut1 = "<<dNdxCut1<<G4endl ;
652
653
654  if(iTkin == fTotBin) // Fermi plato, try from left
655  {
656      position = dNdxCut1*G4UniformRand() ;
657
658      for( iTransfer = 0;
659 iTransfer < G4int((*fPAItransferTable)(iPlace)->GetVectorLength()); iTransfer++ )
660      {
661        if(position >= (*(*fPAItransferTable)(iPlace))(iTransfer)) break ;
662      }
663      transfer = GetEnergyTransfer(iPlace,position,iTransfer);
664  }
665  else
666  {
667    dNdxCut2 = (*fdNdxCutVector)(iPlace+1) ; 
668    // G4cout<<"dNdxCut2 = "<<dNdxCut2<<G4endl ;
669    if(iTkin == 0) // Tkin is too small, trying from right only
670    {
671      position = dNdxCut2*G4UniformRand() ;
672
673      for( iTransfer = 0;
674  iTransfer < G4int((*fPAItransferTable)(iPlace+1)->GetVectorLength()); iTransfer++ )
675      {
676        if(position >= (*(*fPAItransferTable)(iPlace+1))(iTransfer)) break ;
677      }
678      transfer = GetEnergyTransfer(iPlace+1,position,iTransfer);
679    } 
680    else // general case: Tkin between two vectors of the material
681    {
682      E1 = fParticleEnergyVector->GetLowEdgeEnergy(iTkin - 1) ; 
683      E2 = fParticleEnergyVector->GetLowEdgeEnergy(iTkin)     ;
684      W  = 1.0/(E2 - E1) ;
685      W1 = (E2 - scaledTkin)*W ;
686      W2 = (scaledTkin - E1)*W ;
687
688      position = ( dNdxCut1*W1 + dNdxCut2*W2 )*G4UniformRand() ;
689
690        // G4cout<<position<<"\t" ;
691
692      G4int iTrMax1, iTrMax2, iTrMax;
693
694      iTrMax1 = G4int((*fPAItransferTable)(iPlace)->GetVectorLength());
695      iTrMax2 = G4int((*fPAItransferTable)(iPlace+1)->GetVectorLength());
696
697      if (iTrMax1 >= iTrMax2) iTrMax = iTrMax2;
698      else                    iTrMax = iTrMax1;
699
700
701      for( iTransfer = 0; iTransfer < iTrMax; iTransfer++ )
702      {
703          if( position >=
704          ( (*(*fPAItransferTable)(iPlace))(iTransfer)*W1 +
705            (*(*fPAItransferTable)(iPlace+1))(iTransfer)*W2) ) break ;
706      }
707      transfer = GetEnergyTransfer(iPlace,position,iTransfer);
708    }
709  } 
710  // G4cout<<"PAImodel PostStepTransfer = "<<transfer/keV<<" keV"<<G4endl ;
711  if(transfer < 0.0 ) transfer = 0.0 ;
712  // if(transfer < DBL_MIN ) transfer = DBL_MIN;
713
714  return transfer ;
715}
716
717///////////////////////////////////////////////////////////////////////
718//
719// Returns random PAI energy transfer according to passed
720// indexes of particle kinetic
721
722G4double
723G4PAIModel::GetEnergyTransfer( G4int iPlace, G4double position, G4int iTransfer )
724{ 
725  G4int iTransferMax;
726  G4double x1, x2, y1, y2, energyTransfer;
727
728  if(iTransfer == 0)
729  {
730    energyTransfer = (*fPAItransferTable)(iPlace)->GetLowEdgeEnergy(iTransfer);
731  } 
732  else
733  {
734    iTransferMax = G4int((*fPAItransferTable)(iPlace)->GetVectorLength());
735
736    if ( iTransfer >= iTransferMax )  iTransfer = iTransferMax - 1;
737   
738    y1 = (*(*fPAItransferTable)(iPlace))(iTransfer-1);
739    y2 = (*(*fPAItransferTable)(iPlace))(iTransfer);
740
741    x1 = (*fPAItransferTable)(iPlace)->GetLowEdgeEnergy(iTransfer-1);
742    x2 = (*fPAItransferTable)(iPlace)->GetLowEdgeEnergy(iTransfer);
743
744    if ( x1 == x2 )    energyTransfer = x2;
745    else
746    {
747      if ( y1 == y2  ) energyTransfer = x1 + (x2 - x1)*G4UniformRand();
748      else
749      {
750        energyTransfer = x1 + (position - y1)*(x2 - x1)/(y2 - y1);
751      }
752    }
753  }
754  return energyTransfer;
755}
756
757///////////////////////////////////////////////////////////////////////
758
759G4double G4PAIModel::SampleFluctuations( const G4Material* material,
760                                         const G4DynamicParticle* aParticle,
761                                               G4double&,
762                                               G4double& step,
763                                               G4double&)
764{
765  size_t jMat = 0;
766  for(;jMat < fMaterialCutsCoupleVector.size(); ++jMat )
767  {
768    if( material == fMaterialCutsCoupleVector[jMat]->GetMaterial() ) break;
769  }
770  if(jMat == fMaterialCutsCoupleVector.size()) return 0.0;
771
772  fPAItransferTable = fPAIxscBank[jMat];
773  fdNdxCutVector   = fdNdxCutTable[jMat];
774
775  G4int iTkin, iTransfer, iPlace;
776  G4long numOfCollisions=0;
777
778  //G4cout<<"G4PAIModel::SampleFluctuations"<<G4endl ;
779  //G4cout<<"in: "<<fMaterialCutsCoupleVector[jMat]->GetMaterial()->GetName()<<G4endl;
780  G4double loss = 0.0, charge2 ;
781  G4double stepSum = 0., stepDelta, lambda, omega; 
782  G4double position, E1, E2, W1, W2, W, dNdxCut1, dNdxCut2, meanNumber;
783  G4bool numb = true;
784  G4double Tkin       = aParticle->GetKineticEnergy() ;
785  G4double MassRatio  = fMass/aParticle->GetDefinition()->GetPDGMass() ;
786  G4double charge     = aParticle->GetDefinition()->GetPDGCharge() ;
787  charge2             = charge*charge ;
788  G4double TkinScaled = Tkin*MassRatio ;
789
790  for(iTkin=0;iTkin<=fTotBin;iTkin++)
791  {
792    if(TkinScaled < fParticleEnergyVector->GetLowEdgeEnergy(iTkin))   break ;
793  }
794  iPlace = iTkin - 1 ; 
795  if(iPlace < 0) iPlace = 0;
796  else if(iPlace >= fTotBin) iPlace = fTotBin - 1;
797  //G4cout<<"from search, iPlace = "<<iPlace<<G4endl ;
798  dNdxCut1 = (*fdNdxCutVector)(iPlace) ; 
799  //G4cout<<"dNdxCut1 = "<<dNdxCut1<<G4endl ;
800
801  if(iTkin == fTotBin) // Fermi plato, try from left
802  {
803    meanNumber =((*(*fPAItransferTable)(iPlace))(0)-dNdxCut1)*step*charge2;
804    if(meanNumber < 0.) meanNumber = 0. ;
805    //  numOfCollisions = RandPoisson::shoot(meanNumber) ;
806    // numOfCollisions = G4Poisson(meanNumber) ;
807    if( meanNumber > 0.) lambda = step/meanNumber;
808    else                 lambda = DBL_MAX;
809    while(numb)
810    {
811     stepDelta = CLHEP::RandExponential::shoot(lambda);
812     stepSum += stepDelta;
813     if(stepSum >= step) break;
814     numOfCollisions++;
815    }   
816    //G4cout<<"##1 numOfCollisions = "<<numOfCollisions<<G4endl ;
817
818    while(numOfCollisions)
819    {
820      position = dNdxCut1+
821                 ((*(*fPAItransferTable)(iPlace))(0)-dNdxCut1)*G4UniformRand() ;
822
823      for( iTransfer = 0;
824   iTransfer < G4int((*fPAItransferTable)(iPlace)->GetVectorLength()); iTransfer++ )
825      {
826        if(position >= (*(*fPAItransferTable)(iPlace))(iTransfer)) break ;
827      }
828      omega = GetEnergyTransfer(iPlace,position,iTransfer);
829      //G4cout<<"G4PAIModel::SampleFluctuations, omega = "<<omega/keV<<" keV; "<<"\t";
830      loss += omega;
831      numOfCollisions-- ;
832    }
833  }
834  else
835  {
836    dNdxCut2 = (*fdNdxCutVector)(iPlace+1) ; 
837    //G4cout<<"dNdxCut2 = "<<dNdxCut2<< " iTkin= "<<iTkin<<" iPlace= "<<iPlace<<G4endl;
838 
839    if(iTkin == 0) // Tkin is too small, trying from right only
840    {
841      meanNumber =((*(*fPAItransferTable)(iPlace+1))(0)-dNdxCut2)*step*charge2;
842      if( meanNumber < 0. ) meanNumber = 0. ;
843      //  numOfCollisions = CLHEP::RandPoisson::shoot(meanNumber) ;
844      //  numOfCollisions = G4Poisson(meanNumber) ;
845      if( meanNumber > 0.) lambda = step/meanNumber;
846      else                 lambda = DBL_MAX;
847      while(numb)
848        {
849          stepDelta = CLHEP::RandExponential::shoot(lambda);
850          stepSum += stepDelta;
851          if(stepSum >= step) break;
852          numOfCollisions++;
853        }   
854
855      //G4cout<<"##2 numOfCollisions = "<<numOfCollisions<<G4endl ;
856
857      while(numOfCollisions)
858      {
859        position = dNdxCut2+
860                   ((*(*fPAItransferTable)(iPlace+1))(0)-dNdxCut2)*G4UniformRand();
861   
862        for( iTransfer = 0;
863   iTransfer < G4int((*fPAItransferTable)(iPlace+1)->GetVectorLength()); iTransfer++ )
864        {
865          if(position >= (*(*fPAItransferTable)(iPlace+1))(iTransfer)) break ;
866        }
867        omega = GetEnergyTransfer(iPlace,position,iTransfer);
868        //G4cout<<omega/keV<<"\t";
869        loss += omega;
870        numOfCollisions-- ;
871      }
872    } 
873    else // general case: Tkin between two vectors of the material
874    {
875      E1 = fParticleEnergyVector->GetLowEdgeEnergy(iTkin - 1) ; 
876      E2 = fParticleEnergyVector->GetLowEdgeEnergy(iTkin)     ;
877       W = 1.0/(E2 - E1) ;
878      W1 = (E2 - TkinScaled)*W ;
879      W2 = (TkinScaled - E1)*W ;
880
881      //G4cout << fPAItransferTable->size() << G4endl;
882      //G4cout<<"(*(*fPAItransferTable)(iPlace))(0) = "<<
883      //   (*(*fPAItransferTable)(iPlace))(0)<<G4endl ;
884      //G4cout<<"(*(*fPAItransferTable)(iPlace+1))(0) = "<<
885      //     (*(*fPAItransferTable)(iPlace+1))(0)<<G4endl ;
886
887      meanNumber=( ((*(*fPAItransferTable)(iPlace))(0)-dNdxCut1)*W1 + 
888                   ((*(*fPAItransferTable)(iPlace+1))(0)-dNdxCut2)*W2 )*step*charge2;
889      if(meanNumber<0.0) meanNumber = 0.0;
890      //  numOfCollisions = RandPoisson::shoot(meanNumber) ;
891      // numOfCollisions = G4Poisson(meanNumber) ;
892      if( meanNumber > 0.) lambda = step/meanNumber;
893      else                 lambda = DBL_MAX;
894      while(numb)
895        {
896          stepDelta = CLHEP::RandExponential::shoot(lambda);
897          stepSum += stepDelta;
898          if(stepSum >= step) break;
899          numOfCollisions++;
900        }   
901
902      //G4cout<<"##3 numOfCollisions = "<<numOfCollisions<<endl ;
903
904      while(numOfCollisions)
905      {
906        position = dNdxCut1*W1 + dNdxCut2*W2 +
907                 ( ( (*(*fPAItransferTable)(iPlace))(0)-dNdxCut1 )*W1 + 
908                    dNdxCut2+
909                  ( (*(*fPAItransferTable)(iPlace+1))(0)-dNdxCut2 )*W2 )*G4UniformRand();
910
911        // G4cout<<position<<"\t" ;
912
913        for( iTransfer = 0;
914    iTransfer < G4int((*fPAItransferTable)(iPlace)->GetVectorLength()); iTransfer++ )
915        {
916          if( position >=
917          ( (*(*fPAItransferTable)(iPlace))(iTransfer)*W1 + 
918            (*(*fPAItransferTable)(iPlace+1))(iTransfer)*W2) )
919          {
920              break ;
921          }
922        }
923        omega =  GetEnergyTransfer(iPlace,position,iTransfer);
924        //  G4cout<<omega/keV<<"\t";
925        loss += omega;
926        numOfCollisions-- ;   
927      }
928    }
929  } 
930  //G4cout<<"PAIModel AlongStepLoss = "<<loss/keV<<" keV, on step = "
931  //  <<step/mm<<" mm"<<G4endl ;
932  if(loss > Tkin) loss=Tkin;
933  if(loss < 0.  ) loss = 0.;
934  return loss ;
935
936}
937
938//////////////////////////////////////////////////////////////////////
939//
940// Returns the statistical estimation of the energy loss distribution variance
941//
942
943
944G4double G4PAIModel::Dispersion( const G4Material* material, 
945                                 const G4DynamicParticle* aParticle,
946                                       G4double& tmax, 
947                                       G4double& step       )
948{
949  G4double loss, sumLoss=0., sumLoss2=0., sigma2, meanLoss=0.;
950  for(G4int i = 0 ; i < fMeanNumber; i++)
951  {
952    loss      = SampleFluctuations(material,aParticle,tmax,step,meanLoss);
953    sumLoss  += loss;
954    sumLoss2 += loss*loss;
955  }
956  meanLoss = sumLoss/fMeanNumber;
957  sigma2   = meanLoss*meanLoss + (sumLoss2-2*sumLoss*meanLoss)/fMeanNumber;
958  return sigma2;
959}
960
961/////////////////////////////////////////////////////////////////////
962
963G4double G4PAIModel::MaxSecondaryEnergy( const G4ParticleDefinition* p,
964                                         G4double kinEnergy) 
965{
966  G4double tmax = kinEnergy;
967  if(p == fElectron) tmax *= 0.5;
968  else if(p != fPositron) { 
969    G4double mass = p->GetPDGMass();
970    G4double ratio= electron_mass_c2/mass;
971    G4double gamma= kinEnergy/mass + 1.0;
972    tmax = 2.0*electron_mass_c2*(gamma*gamma - 1.) /
973                  (1. + 2.0*gamma*ratio + ratio*ratio);
974  }
975  return tmax;
976}
977
978///////////////////////////////////////////////////////////////
979
980void G4PAIModel::DefineForRegion(const G4Region* r) 
981{
982  fPAIRegionVector.push_back(r);
983}
984
985//
986//
987/////////////////////////////////////////////////
988
989
990
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992
993
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