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G4BetheHeitlerModel Class Reference

#include <G4BetheHeitlerModel.hh>

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Public Member Functions

 G4BetheHeitlerModel (const G4ParticleDefinition *p=0, const G4String &nam="BetheHeitler")
 
virtual ~G4BetheHeitlerModel ()
 
virtual void Initialise (const G4ParticleDefinition *, const G4DataVector &) override
 
virtual void InitialiseLocal (const G4ParticleDefinition *, G4VEmModel *masterModel) override
 
virtual G4double ComputeCrossSectionPerAtom (const G4ParticleDefinition *, G4double kinEnergy, G4double Z, G4double A=0., G4double cut=0., G4double emax=DBL_MAX) override
 
virtual void SampleSecondaries (std::vector< G4DynamicParticle * > *, const G4MaterialCutsCouple *, const G4DynamicParticle *, G4double tmin, G4double maxEnergy) override
 
- Public Member Functions inherited from G4VEmModel
 G4VEmModel (const G4String &nam)
 
virtual ~G4VEmModel ()
 
virtual void InitialiseForMaterial (const G4ParticleDefinition *, const G4Material *)
 
virtual void InitialiseForElement (const G4ParticleDefinition *, G4int Z)
 
virtual G4double ComputeDEDXPerVolume (const G4Material *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=DBL_MAX)
 
virtual G4double CrossSectionPerVolume (const G4Material *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
 
virtual G4double GetPartialCrossSection (const G4Material *, G4int level, const G4ParticleDefinition *, G4double kineticEnergy)
 
virtual G4double ComputeCrossSectionPerShell (const G4ParticleDefinition *, G4int Z, G4int shellIdx, G4double kinEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
 
virtual G4double ChargeSquareRatio (const G4Track &)
 
virtual G4double GetChargeSquareRatio (const G4ParticleDefinition *, const G4Material *, G4double kineticEnergy)
 
virtual G4double GetParticleCharge (const G4ParticleDefinition *, const G4Material *, G4double kineticEnergy)
 
virtual void StartTracking (G4Track *)
 
virtual void CorrectionsAlongStep (const G4MaterialCutsCouple *, const G4DynamicParticle *, G4double &eloss, G4double &niel, G4double length)
 
virtual G4double Value (const G4MaterialCutsCouple *, const G4ParticleDefinition *, G4double kineticEnergy)
 
virtual G4double MinPrimaryEnergy (const G4Material *, const G4ParticleDefinition *, G4double cut=0.0)
 
virtual G4double MinEnergyCut (const G4ParticleDefinition *, const G4MaterialCutsCouple *)
 
virtual void SetupForMaterial (const G4ParticleDefinition *, const G4Material *, G4double kineticEnergy)
 
virtual void DefineForRegion (const G4Region *)
 
virtual void ModelDescription (std::ostream &outFile) const
 
void InitialiseElementSelectors (const G4ParticleDefinition *, const G4DataVector &)
 
std::vector
< G4EmElementSelector * > * 		GetElementSelectors ()
 
void SetElementSelectors (std::vector< G4EmElementSelector * > *)
 
virtual G4double ComputeDEDX (const G4MaterialCutsCouple *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=DBL_MAX)
 
G4double CrossSection (const G4MaterialCutsCouple *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
 
G4double ComputeMeanFreePath (const G4ParticleDefinition *, G4double kineticEnergy, const G4Material *, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
 
G4double ComputeCrossSectionPerAtom (const G4ParticleDefinition *, const G4Element *, G4double kinEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
 
G4int SelectIsotopeNumber (const G4Element *)
 
const G4Element * SelectRandomAtom (const G4MaterialCutsCouple *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
 
const G4Element * SelectRandomAtom (const G4Material *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
 
G4int SelectRandomAtomNumber (const G4Material *)
 
void SetParticleChange (G4VParticleChange *, G4VEmFluctuationModel *f=nullptr)
 
void SetCrossSectionTable (G4PhysicsTable *, G4bool isLocal)
 
G4ElementData * GetElementData ()
 
G4PhysicsTable * GetCrossSectionTable ()
 
G4VEmFluctuationModel * GetModelOfFluctuations ()
 
G4VEmAngularDistribution * GetAngularDistribution ()
 
void SetAngularDistribution (G4VEmAngularDistribution *)
 
G4double HighEnergyLimit () const
 
G4double LowEnergyLimit () const
 
G4double HighEnergyActivationLimit () const
 
G4double LowEnergyActivationLimit () const
 
G4double PolarAngleLimit () const
 
G4double SecondaryThreshold () const
 
G4bool LPMFlag () const
 
G4bool DeexcitationFlag () const
 
G4bool ForceBuildTableFlag () const
 
G4bool UseAngularGeneratorFlag () const
 
void SetAngularGeneratorFlag (G4bool)
 
void SetHighEnergyLimit (G4double)
 
void SetLowEnergyLimit (G4double)
 
void SetActivationHighEnergyLimit (G4double)
 
void SetActivationLowEnergyLimit (G4double)
 
G4bool IsActive (G4double kinEnergy)
 
void SetPolarAngleLimit (G4double)
 
void SetSecondaryThreshold (G4double)
 
void SetLPMFlag (G4bool val)
 
void SetDeexcitationFlag (G4bool val)
 
void SetForceBuildTable (G4bool val)
 
void SetMasterThread (G4bool val)
 
G4bool IsMaster () const
 
G4double MaxSecondaryKinEnergy (const G4DynamicParticle *dynParticle)
 
const G4String & GetName () const
 
void SetCurrentCouple (const G4MaterialCutsCouple *)
 
const G4Element * GetCurrentElement () const
 
const G4Isotope * GetCurrentIsotope () const
 
G4bool IsLocked () const
 
void SetLocked (G4bool)
 

Additional Inherited Members

- Protected Member Functions inherited from G4VEmModel
G4ParticleChangeForLoss * GetParticleChangeForLoss ()
 
G4ParticleChangeForGamma * GetParticleChangeForGamma ()
 
virtual G4double MaxSecondaryEnergy (const G4ParticleDefinition *, G4double kineticEnergy)
 
const G4MaterialCutsCouple * CurrentCouple () const
 
void SetCurrentElement (const G4Element *)
 
- Protected Attributes inherited from G4VEmModel
G4ElementData * fElementData
 
G4VParticleChange * pParticleChange
 
G4PhysicsTable * xSectionTable
 
const std::vector< G4double > * theDensityFactor
 
const std::vector< G4int > * theDensityIdx
 
size_t idxTable
 
- Static Protected Attributes inherited from G4VEmModel
static const G4double inveplus = 1.0/CLHEP::eplus
 

Detailed Description

Definition at line 60 of file G4BetheHeitlerModel.hh.

Constructor & Destructor Documentation

G4BetheHeitlerModel::G4BetheHeitlerModel ( const G4ParticleDefinition *  p = 0,
const G4String &  nam = "BetheHeitler" 
)
explicit

Definition at line 71 of file G4BetheHeitlerModel.cc.

73  : G4VEmModel(nam)
74 {
75  fParticleChange = nullptr;
76  theGamma = G4Gamma::Gamma();
77  thePositron = G4Positron::Positron();
78  theElectron = G4Electron::Electron();
79  g4calc = G4Pow::GetInstance();
80 }
G4Pow::GetInstance
static G4Pow * GetInstance()
Definition: G4Pow.cc:55
G4VEmModel::G4VEmModel
G4VEmModel(const G4String &nam)
Definition: G4VEmModel.cc:68
G4Gamma::Gamma
static G4Gamma * Gamma()
Definition: G4Gamma.cc:86
G4Positron::Positron
static G4Positron * Positron()
Definition: G4Positron.cc:94
G4Electron::Electron
static G4Electron * Electron()
Definition: G4Electron.cc:94

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G4BetheHeitlerModel::~G4BetheHeitlerModel ( )
virtual

Definition at line 84 of file G4BetheHeitlerModel.cc.

85 {}

Member Function Documentation

G4double G4BetheHeitlerModel::ComputeCrossSectionPerAtom ( const G4ParticleDefinition *  ,
G4double  kinEnergy,
G4double  Z,
G4double  A = 0.,
G4double  cut = 0.,
G4double  emax = DBL_MAX 
)
overridevirtual

Reimplemented from G4VEmModel.

Definition at line 107 of file G4BetheHeitlerModel.cc.

116 {
117  G4double xSection = 0.0 ;
118  if ( Z < 0.9 || GammaEnergy <= 2.0*electron_mass_c2 ) { return xSection; }
119 
120  static const G4double GammaEnergyLimit = 1.5*MeV;
121  static const G4double
122  a0= 8.7842e+2*microbarn, a1=-1.9625e+3*microbarn, a2= 1.2949e+3*microbarn,
123  a3=-2.0028e+2*microbarn, a4= 1.2575e+1*microbarn, a5=-2.8333e-1*microbarn;
124 
125  static const G4double
126  b0=-1.0342e+1*microbarn, b1= 1.7692e+1*microbarn, b2=-8.2381 *microbarn,
127  b3= 1.3063 *microbarn, b4=-9.0815e-2*microbarn, b5= 2.3586e-3*microbarn;
128 
129  static const G4double
130  c0=-4.5263e+2*microbarn, c1= 1.1161e+3*microbarn, c2=-8.6749e+2*microbarn,
131  c3= 2.1773e+2*microbarn, c4=-2.0467e+1*microbarn, c5= 6.5372e-1*microbarn;
132 
133  G4double GammaEnergySave = GammaEnergy;
134  if (GammaEnergy < GammaEnergyLimit) { GammaEnergy = GammaEnergyLimit; }
135 
136  G4double X=G4Log(GammaEnergy/electron_mass_c2), X2=X*X, X3=X2*X, X4=X3*X, X5=X4*X;
137 
138  G4double F1 = a0 + a1*X + a2*X2 + a3*X3 + a4*X4 + a5*X5,
139  F2 = b0 + b1*X + b2*X2 + b3*X3 + b4*X4 + b5*X5,
140  F3 = c0 + c1*X + c2*X2 + c3*X3 + c4*X4 + c5*X5;
141 
142  xSection = (Z + 1.)*(F1*Z + F2*Z*Z + F3);
143 
144  if (GammaEnergySave < GammaEnergyLimit) {
145 
146  X = (GammaEnergySave - 2.*electron_mass_c2)
147  / (GammaEnergyLimit - 2.*electron_mass_c2);
148  xSection *= X*X;
149  }
150 
151  xSection = std::max(xSection, 0.);
152  return xSection;
153 }
a0
const G4double a0
Definition: G4IonCoulombCrossSection.cc:68
CLHEP::electron_mass_c2
static constexpr double electron_mass_c2
Definition: PhysicalConstants.h:79
G4Log
G4double G4Log(G4double x)
Definition: G4Log.hh:230
G4INCL::Math::max
T max(const T t1, const T t2)
brief Return the largest of the two arguments
Definition: G4INCLGlobals.hh:112
MeV
static constexpr double MeV
Definition: G4SIunits.hh:214
G4double
double G4double
Definition: G4Types.hh:76
microbarn
static constexpr double microbarn
Definition: G4SIunits.hh:107
Z
G4int Z
Definition: G4ParticleHPJENDLHEData.cc:262

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void G4BetheHeitlerModel::Initialise ( const G4ParticleDefinition *  p,
const G4DataVector &  cuts 
)
overridevirtual

Implements G4VEmModel.

Reimplemented in G4PolarizedGammaConversionModel.

Definition at line 89 of file G4BetheHeitlerModel.cc.

91 {
92  if(!fParticleChange) { fParticleChange = GetParticleChangeForGamma(); }
93  if(IsMaster()) { InitialiseElementSelectors(p, cuts); }
94 }
G4VEmModel::InitialiseElementSelectors
void InitialiseElementSelectors(const G4ParticleDefinition *, const G4DataVector &)
Definition: G4VEmModel.cc:146
G4VEmModel::IsMaster
G4bool IsMaster() const
Definition: G4VEmModel.hh:717
G4VEmModel::GetParticleChangeForGamma
G4ParticleChangeForGamma * GetParticleChangeForGamma()
Definition: G4VEmModel.cc:132

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void G4BetheHeitlerModel::InitialiseLocal ( const G4ParticleDefinition *  ,
G4VEmModel *  masterModel 
)
overridevirtual

Reimplemented from G4VEmModel.

Definition at line 98 of file G4BetheHeitlerModel.cc.

100 {
101  SetElementSelectors(masterModel->GetElementSelectors());
102 }
G4VEmModel::GetElementSelectors
std::vector< G4EmElementSelector * > * GetElementSelectors()
Definition: G4VEmModel.hh:801
G4VEmModel::SetElementSelectors
void SetElementSelectors(std::vector< G4EmElementSelector * > *)
Definition: G4VEmModel.hh:809

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void G4BetheHeitlerModel::SampleSecondaries ( std::vector< G4DynamicParticle * > *  fvect,
const G4MaterialCutsCouple *  couple,
const G4DynamicParticle *  aDynamicGamma,
G4double  tmin,
G4double  maxEnergy 
)
overridevirtual

Implements G4VEmModel.

Reimplemented in G4PolarizedGammaConversionModel.

Definition at line 157 of file G4BetheHeitlerModel.cc.

174 {
175  const G4Material* aMaterial = couple->GetMaterial();
176 
177  G4double GammaEnergy = aDynamicGamma->GetKineticEnergy();
178  G4ParticleMomentum GammaDirection = aDynamicGamma->GetMomentumDirection();
179 
180  G4double epsil ;
181  G4double epsil0 = electron_mass_c2/GammaEnergy ;
182  if(epsil0 > 1.0) { return; }
183 
184  // do it fast if GammaEnergy < Egsmall
185  // select randomly one element constituing the material
186  const G4Element* anElement =
187  SelectRandomAtom(aMaterial, theGamma, GammaEnergy);
188 
189  CLHEP::HepRandomEngine* rndmEngine = G4Random::getTheEngine();
190 
191  static const G4double Egsmall=2.*MeV;
192  if (GammaEnergy < Egsmall) {
193 
194  epsil = epsil0 + (0.5-epsil0)*rndmEngine->flat();
195 
196  } else {
197  // now comes the case with GammaEnergy >= 2. MeV
198 
199  // Extract Coulomb factor for this Element
200  G4double FZ = 8.*(anElement->GetIonisation()->GetlogZ3());
201  if (GammaEnergy > 50.*MeV) { FZ += 8.*(anElement->GetfCoulomb()); }
202 
203  // limits of the screening variable
204  G4double screenfac = 136.*epsil0/(anElement->GetIonisation()->GetZ3());
205  G4double screenmax = exp ((42.24 - FZ)/8.368) - 0.952 ;
206  G4double screenmin = min(4.*screenfac,screenmax);
207 
208  // limits of the energy sampling
209  G4double epsil1 = 0.5 - 0.5*sqrt(1. - screenmin/screenmax) ;
210  G4double epsilmin = max(epsil0,epsil1) , epsilrange = 0.5 - epsilmin;
211 
212  //
213  // sample the energy rate of the created electron (or positron)
214  //
215  //G4double epsil, screenvar, greject ;
216  G4double screenvar, greject ;
217 
218  G4double F10 = ScreenFunction1(screenmin) - FZ;
219  G4double F20 = ScreenFunction2(screenmin) - FZ;
220  G4double NormF1 = max(F10*epsilrange*epsilrange,0.);
221  G4double NormF2 = max(1.5*F20,0.);
222 
223  do {
224  if ( NormF1/(NormF1+NormF2) > rndmEngine->flat()) {
225  epsil = 0.5 - epsilrange*g4calc->A13(rndmEngine->flat());
226  screenvar = screenfac/(epsil*(1-epsil));
227  greject = (ScreenFunction1(screenvar) - FZ)/F10;
228 
229  } else {
230  epsil = epsilmin + epsilrange*rndmEngine->flat();
231  screenvar = screenfac/(epsil*(1-epsil));
232  greject = (ScreenFunction2(screenvar) - FZ)/F20;
233  }
234 
235  // Loop checking, 03-Aug-2015, Vladimir Ivanchenko
236  } while( greject < rndmEngine->flat());
237 
238  } // end of epsil sampling
239 
240  //
241  // fixe charges randomly
242  //
243 
244  G4double ElectTotEnergy, PositTotEnergy;
245  if (rndmEngine->flat() > 0.5) {
246 
247  ElectTotEnergy = (1.-epsil)*GammaEnergy;
248  PositTotEnergy = epsil*GammaEnergy;
249 
250  } else {
251 
252  PositTotEnergy = (1.-epsil)*GammaEnergy;
253  ElectTotEnergy = epsil*GammaEnergy;
254  }
255 
256  //
257  // scattered electron (positron) angles. ( Z - axis along the parent photon)
258  //
259  // universal distribution suggested by L. Urban
260  // (Geant3 manual (1993) Phys211),
261  // derived from Tsai distribution (Rev Mod Phys 49,421(1977))
262 
263  G4double u= - G4Log(rndmEngine->flat()*rndmEngine->flat());
264 
265  if (9. > 36.*rndmEngine->flat()) { u *= 1.6; }
266  else { u *= 0.53333; }
267 
268  G4double TetEl = u*electron_mass_c2/ElectTotEnergy;
269  G4double TetPo = u*electron_mass_c2/PositTotEnergy;
270  G4double Phi = twopi * rndmEngine->flat();
271  G4double dxEl= sin(TetEl)*cos(Phi),dyEl= sin(TetEl)*sin(Phi),dzEl=cos(TetEl);
272  G4double dxPo=-sin(TetPo)*cos(Phi),dyPo=-sin(TetPo)*sin(Phi),dzPo=cos(TetPo);
273 
274  //
275  // kinematic of the created pair
276  //
277  // the electron and positron are assumed to have a symetric
278  // angular distribution with respect to the Z axis along the parent photon.
279 
280  G4double ElectKineEnergy = max(0.,ElectTotEnergy - electron_mass_c2);
281 
282  G4ThreeVector ElectDirection (dxEl, dyEl, dzEl);
283  ElectDirection.rotateUz(GammaDirection);
284 
285  // create G4DynamicParticle object for the particle1
286  G4DynamicParticle* aParticle1= new G4DynamicParticle(
287  theElectron,ElectDirection,ElectKineEnergy);
288 
289  // the e+ is always created (even with Ekine=0) for further annihilation.
290 
291  G4double PositKineEnergy = max(0.,PositTotEnergy - electron_mass_c2);
292 
293  G4ThreeVector PositDirection (dxPo, dyPo, dzPo);
294  PositDirection.rotateUz(GammaDirection);
295 
296  // create G4DynamicParticle object for the particle2
297  G4DynamicParticle* aParticle2= new G4DynamicParticle(
298  thePositron,PositDirection,PositKineEnergy);
299 
300  // Fill output vector
301  fvect->push_back(aParticle1);
302  fvect->push_back(aParticle2);
303 
304  // kill incident photon
305  fParticleChange->SetProposedKineticEnergy(0.);
306  fParticleChange->ProposeTrackStatus(fStopAndKill);
307 }
G4DynamicParticle::GetKineticEnergy
G4double GetKineticEnergy() const
G4Element::GetfCoulomb
G4double GetfCoulomb() const
Definition: G4Element.hh:191
CLHEP::HepRandomEngine::flat
virtual double flat()=0
F20
#define F20
Definition: G4ErrorMatrix.cc:900
twopi
static constexpr double twopi
Definition: G4SIunits.hh:76
CLHEP::electron_mass_c2
static constexpr double electron_mass_c2
Definition: PhysicalConstants.h:79
G4DynamicParticle::GetMomentumDirection
const G4ThreeVector & GetMomentumDirection() const
F10
#define F10
Definition: G4ErrorMatrix.cc:895
G4AblaRandom::flat
double flat()
Definition: G4AblaRandom.cc:47
G4IonisParamElm::GetlogZ3
G4double GetlogZ3() const
Definition: G4IonisParamElm.hh:63
G4Log
G4double G4Log(G4double x)
Definition: G4Log.hh:230
G4Pow::A13
G4double A13(G4double A) const
Definition: G4Pow.hh:132
G4INCL::Math::max
T max(const T t1, const T t2)
brief Return the largest of the two arguments
Definition: G4INCLGlobals.hh:112
G4Element::GetIonisation
G4IonisParamElm * GetIonisation() const
Definition: G4Element.hh:199
G4INCL::Math::min
T min(const T t1, const T t2)
brief Return the smallest of the two arguments
Definition: G4INCLGlobals.hh:117
fStopAndKill
Definition: G4TrackStatus.hh:56
G4ParticleChangeForGamma::SetProposedKineticEnergy
void SetProposedKineticEnergy(G4double proposedKinEnergy)
Definition: G4ParticleChangeForGamma.hh:129
MeV
static constexpr double MeV
Definition: G4SIunits.hh:214
G4double
double G4double
Definition: G4Types.hh:76
G4VParticleChange::ProposeTrackStatus
void ProposeTrackStatus(G4TrackStatus status)
G4IonisParamElm::GetZ3
G4double GetZ3() const
Definition: G4IonisParamElm.hh:61
G4VEmModel::SelectRandomAtom
const G4Element * SelectRandomAtom(const G4MaterialCutsCouple *, const G4ParticleDefinition *, G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)
Definition: G4VEmModel.hh:541
G4MaterialCutsCouple::GetMaterial
const G4Material * GetMaterial() const
Definition: G4MaterialCutsCouple.hh:150

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The documentation for this class was generated from the following files: