source: trunk/source/processes/electromagnetic/polarisation/src/G4ePolarizedIonisation.cc @ 846

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27// $Id: G4ePolarizedIonisation.cc,v 1.5 2007/07/10 09:35:37 schaelic Exp $
28// GEANT4 tag $Name: geant4-09-01-patch-02 $
29// -------------------------------------------------------------------
30//
31// GEANT4 Class file
32//
33//
34// File name:     G4ePolarizedIonisation
35//
36// Author:        A.Schaelicke on base of Vladimir Ivanchenko code
37//
38// Creation date: 10.11.2005
39//
40// Modifications:
41//
42// 10-11-05, include polarization description (A.Schaelicke)
43// , create asymmetry table and determine interactionlength
44// , update polarized differential cross section
45//
46// 20-08-06, modified interface (A.Schaelicke)
47// 11-06-07, add PostStepGetPhysicalInteractionLength (A.Schalicke)
48//
49// Class Description:
50//
51//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
52//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
53
54#include "G4ePolarizedIonisation.hh"
55#include "G4Electron.hh"
56#include "G4UniversalFluctuation.hh"
57#include "G4BohrFluctuations.hh"
58#include "G4UnitsTable.hh"
59
60#include "G4PolarizedMollerBhabhaModel.hh"
61#include "G4ProductionCutsTable.hh"
62#include "G4PolarizationManager.hh"
63#include "G4PolarizationHelper.hh"
64#include "G4StokesVector.hh"
65
66//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
67
68G4ePolarizedIonisation::G4ePolarizedIonisation(const G4String& name)
69  : G4VEnergyLossProcess(name),
70    theElectron(G4Electron::Electron()),
71    isElectron(true),
72    isInitialised(false),
73    theAsymmetryTable(NULL),
74    theTransverseAsymmetryTable(NULL)
75{
76  verboseLevel=0;
77  SetDEDXBinning(120);
78  SetLambdaBinning(120);
79  numBinAsymmetryTable=120;
80
81  SetMinKinEnergy(0.1*keV);
82  SetMaxKinEnergy(100.0*TeV);
83  //  PrintInfoDefinition();
84}
85
86//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
87
88G4ePolarizedIonisation::~G4ePolarizedIonisation()
89{
90  if (theAsymmetryTable) {
91    theAsymmetryTable->clearAndDestroy();
92    delete theAsymmetryTable;
93  }
94  if (theTransverseAsymmetryTable) {
95    theTransverseAsymmetryTable->clearAndDestroy();
96    delete theTransverseAsymmetryTable;
97  }
98}
99
100//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
101
102void G4ePolarizedIonisation::InitialiseEnergyLossProcess(
103                    const G4ParticleDefinition* part,
104                    const G4ParticleDefinition* /*part2*/)
105{
106  if(!isInitialised) {
107
108    if(part == G4Positron::Positron()) isElectron = false;
109    SetSecondaryParticle(theElectron);
110
111
112
113    flucModel = new G4UniversalFluctuation();
114    //flucModel = new G4BohrFluctuations();
115
116    //    G4VEmModel* em = new G4MollerBhabhaModel();
117    emModel = new G4PolarizedMollerBhabhaModel;
118    emModel->SetLowEnergyLimit(100*eV);
119    emModel->SetHighEnergyLimit(100*TeV);
120    AddEmModel(1, emModel, flucModel);
121
122    isInitialised = true;
123  }
124}
125
126//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
127
128void G4ePolarizedIonisation::PrintInfo()
129{
130  G4cout << "      Delta cross sections from Moller+Bhabha, "
131         << "good description from 1 KeV to 100 GeV."
132         << G4endl;
133}
134
135//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
136
137G4double G4ePolarizedIonisation::GetMeanFreePath(const G4Track& track,
138                                              G4double s,
139                                              G4ForceCondition* cond)
140{
141  // *** get unploarised mean free path from lambda table ***
142  G4double mfp = G4VEnergyLossProcess::GetMeanFreePath(track, s, cond);
143
144
145  // *** get asymmetry, if target is polarized ***
146  G4VPhysicalVolume*  aPVolume  = track.GetVolume();
147  G4LogicalVolume*    aLVolume  = aPVolume->GetLogicalVolume();
148
149  G4PolarizationManager * polarizationManger = G4PolarizationManager::GetInstance();
150  const G4bool volumeIsPolarized = polarizationManger->IsPolarized(aLVolume);
151  const G4StokesVector ePolarization = track.GetPolarization();
152
153  if (mfp != DBL_MAX &&  volumeIsPolarized && !ePolarization.IsZero()) {
154    const G4DynamicParticle* aDynamicElectron = track.GetDynamicParticle();
155    const G4double eEnergy = aDynamicElectron->GetKineticEnergy();
156    const G4ParticleMomentum eDirection0 = aDynamicElectron->GetMomentumDirection();
157
158    G4StokesVector volumePolarization = polarizationManger->GetVolumePolarization(aLVolume);
159
160    G4bool isOutRange;
161    size_t idx = CurrentMaterialCutsCoupleIndex();
162    G4double lAsymmetry = (*theAsymmetryTable)(idx)->
163                                  GetValue(eEnergy, isOutRange);
164    G4double tAsymmetry = (*theTransverseAsymmetryTable)(idx)->
165                                  GetValue(eEnergy, isOutRange);
166
167    // calculate longitudinal spin component
168    G4double polZZ = ePolarization.z()*
169                        volumePolarization*eDirection0;
170    // calculate transvers spin components
171    G4double polXX = ePolarization.x()*
172                        volumePolarization*G4PolarizationHelper::GetParticleFrameX(eDirection0);
173    G4double polYY = ePolarization.y()*
174                        volumePolarization*G4PolarizationHelper::GetParticleFrameY(eDirection0);
175
176
177    G4double impact = 1. + polZZ*lAsymmetry + (polXX + polYY)*tAsymmetry;
178    // determine polarization dependent mean free path
179    mfp /= impact;
180    if (mfp <=0.) {
181     G4cout <<"PV impact ( "<<polXX<<" , "<<polYY<<" , "<<polZZ<<" )"<<G4endl;
182     G4cout << " impact on MFP is "<< impact <<G4endl;
183     G4cout<<" lAsymmetry= "<<lAsymmetry<<" ("<<std::fabs(lAsymmetry)-1.<<")\n";
184     G4cout<<" tAsymmetry= "<<tAsymmetry<<" ("<<std::fabs(tAsymmetry)-1.<<")\n";
185    }
186  }
187
188  return mfp;
189}
190
191G4double G4ePolarizedIonisation::PostStepGetPhysicalInteractionLength(const G4Track& track,
192                                              G4double s,
193                                              G4ForceCondition* cond)
194{
195  // *** get unploarised mean free path from lambda table ***
196  G4double mfp = G4VEnergyLossProcess::PostStepGetPhysicalInteractionLength(track, s, cond);
197
198
199  // *** get asymmetry, if target is polarized ***
200  G4VPhysicalVolume*  aPVolume  = track.GetVolume();
201  G4LogicalVolume*    aLVolume  = aPVolume->GetLogicalVolume();
202
203  G4PolarizationManager * polarizationManger = G4PolarizationManager::GetInstance();
204  const G4bool volumeIsPolarized = polarizationManger->IsPolarized(aLVolume);
205  const G4StokesVector ePolarization = track.GetPolarization();
206
207  if (mfp != DBL_MAX &&  volumeIsPolarized && !ePolarization.IsZero()) {
208    const G4DynamicParticle* aDynamicElectron = track.GetDynamicParticle();
209    const G4double eEnergy = aDynamicElectron->GetKineticEnergy();
210    const G4ParticleMomentum eDirection0 = aDynamicElectron->GetMomentumDirection();
211
212    G4StokesVector volumePolarization = polarizationManger->GetVolumePolarization(aLVolume);
213
214    G4bool isOutRange;
215    size_t idx = CurrentMaterialCutsCoupleIndex();
216    G4double lAsymmetry = (*theAsymmetryTable)(idx)->
217                                  GetValue(eEnergy, isOutRange);
218    G4double tAsymmetry = (*theTransverseAsymmetryTable)(idx)->
219                                  GetValue(eEnergy, isOutRange);
220
221    // calculate longitudinal spin component
222    G4double polZZ = ePolarization.z()*
223                        volumePolarization*eDirection0;
224    // calculate transvers spin components
225    G4double polXX = ePolarization.x()*
226                        volumePolarization*G4PolarizationHelper::GetParticleFrameX(eDirection0);
227    G4double polYY = ePolarization.y()*
228                        volumePolarization*G4PolarizationHelper::GetParticleFrameY(eDirection0);
229
230
231    G4double impact = 1. + polZZ*lAsymmetry + (polXX + polYY)*tAsymmetry;
232    // determine polarization dependent mean free path
233    mfp /= impact;
234    if (mfp <=0.) {
235     G4cout <<"PV impact ( "<<polXX<<" , "<<polYY<<" , "<<polZZ<<" )"<<G4endl;
236     G4cout << " impact on MFP is "<< impact <<G4endl;
237     G4cout<<" lAsymmetry= "<<lAsymmetry<<" ("<<std::fabs(lAsymmetry)-1.<<")\n";
238     G4cout<<" tAsymmetry= "<<tAsymmetry<<" ("<<std::fabs(tAsymmetry)-1.<<")\n";
239    }
240  }
241
242  return mfp;
243}
244
245//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
246void G4ePolarizedIonisation::BuildPhysicsTable(const G4ParticleDefinition& part)
247{
248  // *** build DEDX and (unpolarized) cross section tables
249  G4VEnergyLossProcess::BuildPhysicsTable(part);
250  //  G4PhysicsTable* pt =
251  //  BuildDEDXTable();
252
253
254  // *** build asymmetry-table
255  if (theAsymmetryTable) {
256    theAsymmetryTable->clearAndDestroy(); delete theAsymmetryTable;}
257  if (theTransverseAsymmetryTable) {
258    theTransverseAsymmetryTable->clearAndDestroy(); delete theTransverseAsymmetryTable;}
259
260  const G4ProductionCutsTable* theCoupleTable=
261        G4ProductionCutsTable::GetProductionCutsTable();
262  size_t numOfCouples = theCoupleTable->GetTableSize();
263
264  theAsymmetryTable = new G4PhysicsTable(numOfCouples);
265  theTransverseAsymmetryTable = new G4PhysicsTable(numOfCouples);
266
267  for (size_t j=0 ; j < numOfCouples; j++ ) {
268    // get cut value
269    const G4MaterialCutsCouple* couple = theCoupleTable->GetMaterialCutsCouple(j);
270
271    G4double tcutmin = emModel->MinEnergyCut(&part, couple);
272    G4double cut = (*theCoupleTable->GetEnergyCutsVector(1))[j];
273    cut = std::max(cut, tcutmin);
274
275    //create physics vectors then fill it (same parameters as lambda vector)
276    G4PhysicsVector * ptrVectorA = LambdaPhysicsVector(couple,cut);
277    G4PhysicsVector * ptrVectorB = LambdaPhysicsVector(couple,cut);
278
279    for (size_t i = 0 ; i < numBinAsymmetryTable ; i++ ) {
280      G4double lowEdgeEnergy = ptrVectorA->GetLowEdgeEnergy(i);
281      G4double tasm=0.;
282      G4double asym = ComputeAsymmetry(lowEdgeEnergy, couple, part, cut, tasm);
283      ptrVectorA->PutValue(i,asym);
284      ptrVectorB->PutValue(i,tasm);
285    }
286    theAsymmetryTable->insertAt( j , ptrVectorA ) ;
287    theTransverseAsymmetryTable->insertAt( j , ptrVectorB ) ;
288  }
289
290}
291//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
292
293G4double G4ePolarizedIonisation::ComputeAsymmetry(G4double energy,
294                                         const G4MaterialCutsCouple* couple,
295                                               const G4ParticleDefinition& aParticle,
296                                               G4double cut,
297                                               G4double & tAsymmetry)
298{
299  G4double lAsymmetry = 0.0;
300           tAsymmetry = 0.0;
301  if (isElectron) {lAsymmetry = tAsymmetry = -1.0;}
302
303  // calculate polarized cross section
304  theTargetPolarization=G4ThreeVector(0.,0.,1.);
305  emModel->SetTargetPolarization(theTargetPolarization);
306  emModel->SetBeamPolarization(theTargetPolarization);
307  G4double sigma2=emModel->CrossSection(couple,&aParticle,energy,cut,energy);
308
309  // calculate transversely polarized cross section
310  theTargetPolarization=G4ThreeVector(1.,0.,0.);
311  emModel->SetTargetPolarization(theTargetPolarization);
312  emModel->SetBeamPolarization(theTargetPolarization);
313  G4double sigma3=emModel->CrossSection(couple,&aParticle,energy,cut,energy);
314
315  // calculate unpolarized cross section
316  theTargetPolarization=G4ThreeVector();
317  emModel->SetTargetPolarization(theTargetPolarization);
318  emModel->SetBeamPolarization(theTargetPolarization);
319  G4double sigma0=emModel->CrossSection(couple,&aParticle,energy,cut,energy);
320  // determine assymmetries
321  if (sigma0>0.) {
322    lAsymmetry=sigma2/sigma0-1.;
323    tAsymmetry=sigma3/sigma0-1.;
324  }
325  if (std::fabs(lAsymmetry)>1.) {
326    G4cout<<" energy="<<energy<<"\n";
327    G4cout<<"WARNING lAsymmetry= "<<lAsymmetry<<" ("<<std::fabs(lAsymmetry)-1.<<")\n";
328  }
329  if (std::fabs(tAsymmetry)>1.) {
330    G4cout<<" energy="<<energy<<"\n";
331    G4cout<<"WARNING tAsymmetry= "<<tAsymmetry<<" ("<<std::fabs(tAsymmetry)-1.<<")\n";
332  }
333//   else {
334//     G4cout<<"        tAsymmetry= "<<tAsymmetry<<" ("<<std::fabs(tAsymmetry)-1.<<")\n";
335//   }
336  return lAsymmetry;
337}
338
339
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