Geant4 10.7.0
Toolkit for the simulation of the passage of particles through matter
Loading...
Searching...
No Matches
Public Member Functions | List of all members
G4GammaConversionToMuons Class Reference

#include <G4GammaConversionToMuons.hh>

+ Inheritance diagram for G4GammaConversionToMuons:

Public Member Functions

 G4GammaConversionToMuons (const G4String &processName="GammaToMuPair", G4ProcessType type=fElectromagnetic)
 
 ~G4GammaConversionToMuons () override
 
G4bool IsApplicable (const G4ParticleDefinition &) override
 
void BuildPhysicsTable (const G4ParticleDefinition &) override
 
void PrintInfoDefinition ()
 
void SetCrossSecFactor (G4double fac)
 
G4double GetCrossSecFactor () const
 
G4double GetMeanFreePath (const G4Track &aTrack, G4double previousStepSize, G4ForceCondition *condition) override
 
G4double GetCrossSectionPerAtom (const G4DynamicParticle *aDynamicGamma, const G4Element *anElement)
 
G4VParticleChange * PostStepDoIt (const G4Track &aTrack, const G4Step &aStep) override
 
G4double ComputeCrossSectionPerAtom (G4double GammaEnergy, G4int Z)
 
G4double ComputeMeanFreePath (G4double GammaEnergy, const G4Material *aMaterial)
 
- Public Member Functions inherited from G4VDiscreteProcess
 G4VDiscreteProcess (const G4String &aName, G4ProcessType aType=fNotDefined)
 
 G4VDiscreteProcess (G4VDiscreteProcess &)
 
virtual ~G4VDiscreteProcess ()
 
G4VDiscreteProcess & operator= (const G4VDiscreteProcess &)=delete
 
virtual G4double PostStepGetPhysicalInteractionLength (const G4Track &track, G4double previousStepSize, G4ForceCondition *condition)
 
virtual G4VParticleChange * PostStepDoIt (const G4Track &, const G4Step &)
 
virtual G4double AlongStepGetPhysicalInteractionLength (const G4Track &, G4double, G4double, G4double &, G4GPILSelection *)
 
virtual G4double AtRestGetPhysicalInteractionLength (const G4Track &, G4ForceCondition *)
 
virtual G4VParticleChange * AtRestDoIt (const G4Track &, const G4Step &)
 
virtual G4VParticleChange * AlongStepDoIt (const G4Track &, const G4Step &)
 
- Public Member Functions inherited from G4VProcess
 G4VProcess (const G4String &aName="NoName", G4ProcessType aType=fNotDefined)
 
 G4VProcess (const G4VProcess &right)
 
virtual ~G4VProcess ()
 
G4VProcess & operator= (const G4VProcess &)=delete
 
G4bool operator== (const G4VProcess &right) const
 
G4bool operator!= (const G4VProcess &right) const
 
virtual G4VParticleChange * PostStepDoIt (const G4Track &track, const G4Step &stepData)=0
 
virtual G4VParticleChange * AlongStepDoIt (const G4Track &track, const G4Step &stepData)=0
 
virtual G4VParticleChange * AtRestDoIt (const G4Track &track, const G4Step &stepData)=0
 
virtual G4double AlongStepGetPhysicalInteractionLength (const G4Track &track, G4double previousStepSize, G4double currentMinimumStep, G4double &proposedSafety, G4GPILSelection *selection)=0
 
virtual G4double AtRestGetPhysicalInteractionLength (const G4Track &track, G4ForceCondition *condition)=0
 
virtual G4double PostStepGetPhysicalInteractionLength (const G4Track &track, G4double previousStepSize, G4ForceCondition *condition)=0
 
G4double GetCurrentInteractionLength () const
 
void SetPILfactor (G4double value)
 
G4double GetPILfactor () const
 
G4double AlongStepGPIL (const G4Track &track, G4double previousStepSize, G4double currentMinimumStep, G4double &proposedSafety, G4GPILSelection *selection)
 
G4double AtRestGPIL (const G4Track &track, G4ForceCondition *condition)
 
G4double PostStepGPIL (const G4Track &track, G4double previousStepSize, G4ForceCondition *condition)
 
virtual G4bool IsApplicable (const G4ParticleDefinition &)
 
virtual void BuildPhysicsTable (const G4ParticleDefinition &)
 
virtual void PreparePhysicsTable (const G4ParticleDefinition &)
 
virtual G4bool StorePhysicsTable (const G4ParticleDefinition *, const G4String &, G4bool)
 
virtual G4bool RetrievePhysicsTable (const G4ParticleDefinition *, const G4String &, G4bool)
 
const G4String & GetPhysicsTableFileName (const G4ParticleDefinition *, const G4String &directory, const G4String &tableName, G4bool ascii=false)
 
const G4String & GetProcessName () const
 
G4ProcessType GetProcessType () const
 
void SetProcessType (G4ProcessType)
 
G4int GetProcessSubType () const
 
void SetProcessSubType (G4int)
 
virtual void StartTracking (G4Track *)
 
virtual void EndTracking ()
 
virtual void SetProcessManager (const G4ProcessManager *)
 
virtual const G4ProcessManager * GetProcessManager ()
 
virtual void ResetNumberOfInteractionLengthLeft ()
 
G4double GetNumberOfInteractionLengthLeft () const
 
G4double GetTotalNumberOfInteractionLengthTraversed () const
 
G4bool isAtRestDoItIsEnabled () const
 
G4bool isAlongStepDoItIsEnabled () const
 
G4bool isPostStepDoItIsEnabled () const
 
virtual void DumpInfo () const
 
virtual void ProcessDescription (std::ostream &outfile) const
 
void SetVerboseLevel (G4int value)
 
G4int GetVerboseLevel () const
 
virtual void SetMasterProcess (G4VProcess *masterP)
 
const G4VProcess * GetMasterProcess () const
 
virtual void BuildWorkerPhysicsTable (const G4ParticleDefinition &part)
 
virtual void PrepareWorkerPhysicsTable (const G4ParticleDefinition &)
 

Additional Inherited Members

- Static Public Member Functions inherited from G4VProcess
static const G4String & GetProcessTypeName (G4ProcessType)
 
virtual G4double GetMeanFreePath (const G4Track &aTrack, G4double previousStepSize, G4ForceCondition *condition)=0
 
- Protected Member Functions inherited from G4VProcess
void SubtractNumberOfInteractionLengthLeft (G4double prevStepSize)
 
void ClearNumberOfInteractionLengthLeft ()
 
- Protected Attributes inherited from G4VProcess
const G4ProcessManager * aProcessManager = nullptr
 
G4VParticleChange * pParticleChange = nullptr
 
G4ParticleChange aParticleChange
 
G4double theNumberOfInteractionLengthLeft = -1.0
 
G4double currentInteractionLength = -1.0
 
G4double theInitialNumberOfInteractionLength = -1.0
 
G4String theProcessName
 
G4String thePhysicsTableFileName
 
G4ProcessType theProcessType = fNotDefined
 
G4int theProcessSubType = -1
 
G4double thePILfactor = 1.0
 
G4int verboseLevel = 0
 
G4bool enableAtRestDoIt = true
 
G4bool enableAlongStepDoIt = true
 
G4bool enablePostStepDoIt = true
 

Detailed Description

Definition at line 60 of file G4GammaConversionToMuons.hh.

Constructor & Destructor Documentation

◆ G4GammaConversionToMuons()

G4GammaConversionToMuons::G4GammaConversionToMuons ( const G4String &  processName = "GammaToMuPair",
G4ProcessType  type = fElectromagnetic 
)
explicit

Definition at line 60 of file G4GammaConversionToMuons.cc.

62 : G4VDiscreteProcess (processName, type),
63 Mmuon(G4MuonPlus::MuonPlus()->GetPDGMass()),
64 Rc(elm_coupling/Mmuon),
65 LimitEnergy (5.*Mmuon),
66 LowestEnergyLimit (2.*Mmuon),
67 HighestEnergyLimit(1e12*GeV), // ok to 1e12GeV, then LPM suppression
68 Energy5DLimit(0.0),
69 CrossSecFactor(1.),
70 f5Dmodel(nullptr),
71 theGamma(G4Gamma::Gamma()),
72 theMuonPlus(G4MuonPlus::MuonPlus()),
73 theMuonMinus(G4MuonMinus::MuonMinus())
74{
75 SetProcessSubType(fGammaConversionToMuMu);
76 MeanFreePath = DBL_MAX;
77 fManager = G4LossTableManager::Instance();
78 fManager->Register(this);
79}
fGammaConversionToMuMu
@ fGammaConversionToMuMu
Definition: G4EmProcessSubType.hh:61
G4Gamma::Gamma
static G4Gamma * Gamma()
Definition: G4Gamma.cc:85
G4LossTableManager::Instance
static G4LossTableManager * Instance()
Definition: G4LossTableManager.cc:87
G4LossTableManager::Register
void Register(G4VEnergyLossProcess *p)
Definition: G4LossTableManager.cc:197
G4MuonMinus::MuonMinus
static G4MuonMinus * MuonMinus()
Definition: G4MuonMinus.cc:99
G4MuonPlus::MuonPlus
static G4MuonPlus * MuonPlus()
Definition: G4MuonPlus.cc:98
G4VProcess::SetProcessSubType
void SetProcessSubType(G4int)
Definition: G4VProcess.hh:406
DBL_MAX
#define DBL_MAX
Definition: templates.hh:62

◆ ~G4GammaConversionToMuons()

G4GammaConversionToMuons::~G4GammaConversionToMuons ( )
override

Definition at line 83 of file G4GammaConversionToMuons.cc.

84{
85 fManager->DeRegister(this);
86}
G4LossTableManager::DeRegister
void DeRegister(G4VEnergyLossProcess *p)
Definition: G4LossTableManager.cc:240

Member Function Documentation

◆ BuildPhysicsTable()

void G4GammaConversionToMuons::BuildPhysicsTable ( const G4ParticleDefinition &  p)
overridevirtual

Reimplemented from G4VProcess.

Definition at line 97 of file G4GammaConversionToMuons.cc.

99{ //here no tables, just calling PrintInfoDefinition
100 Energy5DLimit = G4EmParameters::Instance()->MaxEnergyFor5DMuPair();
101 if(Energy5DLimit > 0.0 && !f5Dmodel) {
102 f5Dmodel = new G4BetheHeitler5DModel();
103 f5Dmodel->SetLeptonPair(theMuonPlus, theMuonMinus);
104 const size_t numElems = G4ProductionCutsTable::GetProductionCutsTable()->GetTableSize();
105 const G4DataVector cuts(numElems);
106 f5Dmodel->Initialise(&p, cuts);
107 }
108 PrintInfoDefinition();
109}
G4BetheHeitler5DModel::Initialise
virtual void Initialise(const G4ParticleDefinition *, const G4DataVector &) override
Definition: G4BetheHeitler5DModel.cc:157
G4BetheHeitler5DModel::SetLeptonPair
void SetLeptonPair(const G4ParticleDefinition *p1, const G4ParticleDefinition *p2)
Definition: G4BetheHeitler5DModel.cc:198
G4EmParameters::Instance
static G4EmParameters * Instance()
Definition: G4EmParameters.cc:67
G4EmParameters::MaxEnergyFor5DMuPair
G4double MaxEnergyFor5DMuPair() const
Definition: G4EmParameters.cc:644
G4ProductionCutsTable::GetTableSize
std::size_t GetTableSize() const
Definition: G4ProductionCutsTable.hh:239
G4ProductionCutsTable::GetProductionCutsTable
static G4ProductionCutsTable * GetProductionCutsTable()
Definition: G4ProductionCutsTable.cc:58

Referenced by G4GammaGeneralProcess::BuildPhysicsTable().

◆ ComputeCrossSectionPerAtom()

G4double G4GammaConversionToMuons::ComputeCrossSectionPerAtom ( G4double  GammaEnergy,
G4int  Z 
)

Definition at line 174 of file G4GammaConversionToMuons.cc.

180{
181 if(Egam <= LowestEnergyLimit) { return 0.0; }
182
183 G4NistManager* nist = G4NistManager::Instance();
184
185 G4double PowThres,Ecor,B,Dn,Zthird,Winfty,WMedAppr,
186 Wsatur,sigfac;
187
188 if(Z==1) // special case of Hydrogen
189 { B=202.4;
190 Dn=1.49;
191 }
192 else
193 { B=183.;
194 Dn=1.54*nist->GetA27(Z);
195 }
196 Zthird=1./nist->GetZ13(Z); // Z**(-1/3)
197 Winfty=B*Zthird*Mmuon/(Dn*electron_mass_c2);
198 WMedAppr=1./(4.*Dn*sqrte*Mmuon);
199 Wsatur=Winfty/WMedAppr;
200 sigfac=4.*fine_structure_const*Z*Z*Rc*Rc;
201 PowThres=1.479+0.00799*Dn;
202 Ecor=-18.+4347./(B*Zthird);
203
204 G4double CorFuc=1.+.04*G4Log(1.+Ecor/Egam);
205 //G4double Eg=pow(1.-4.*Mmuon/Egam,PowThres)*pow( pow(Wsatur,PowSat)+
206 // pow(Egam,PowSat),1./PowSat); // threshold and saturation
207 G4double Eg=G4Exp(G4Log(1.-4.*Mmuon/Egam)*PowThres)*
208 G4Exp(G4Log( G4Exp(G4Log(Wsatur)*PowSat)+G4Exp(G4Log(Egam)*PowSat))/PowSat);
209 G4double CrossSection=7./9.*sigfac*G4Log(1.+WMedAppr*CorFuc*Eg);
210 CrossSection*=CrossSecFactor; // increase the CrossSection by (by default 1)
211 return CrossSection;
212}
B
double B(double temperature)
Definition: G4DNAElectronHoleRecombination.cc:69
G4Exp
G4double G4Exp(G4double initial_x)
Exponential Function double precision.
Definition: G4Exp.hh:179
G4Log
G4double G4Log(G4double x)
Definition: G4Log.hh:226
G4double
double G4double
Definition: G4Types.hh:83
G4NistManager::GetA27
G4double GetA27(G4int Z) const
Definition: G4NistManager.hh:603
G4NistManager::GetZ13
G4double GetZ13(G4double Z) const
Definition: G4NistManager.hh:589
G4NistManager::Instance
static G4NistManager * Instance()
Definition: G4NistManager.cc:70

Referenced by ComputeMeanFreePath(), and GetCrossSectionPerAtom().

◆ ComputeMeanFreePath()

G4double G4GammaConversionToMuons::ComputeMeanFreePath ( G4double  GammaEnergy,
const G4Material *  aMaterial 
)

Definition at line 133 of file G4GammaConversionToMuons.cc.

137{
138 if(GammaEnergy <= LowestEnergyLimit) { return DBL_MAX; }
139 const G4ElementVector* theElementVector = aMaterial->GetElementVector();
140 const G4double* NbOfAtomsPerVolume = aMaterial->GetVecNbOfAtomsPerVolume();
141
142 G4double SIGMA = 0.0;
143 G4double fact = 1.0;
144 G4double e = GammaEnergy;
145 // low energy approximation as in Bethe-Heitler model
146 if(e < LimitEnergy) {
147 G4double y = (e - LowestEnergyLimit)/(LimitEnergy - LowestEnergyLimit);
148 fact = y*y;
149 e = LimitEnergy;
150 }
151
152 for ( size_t i=0 ; i < aMaterial->GetNumberOfElements(); ++i)
153 {
154 SIGMA += NbOfAtomsPerVolume[i] * fact *
155 ComputeCrossSectionPerAtom(e, (*theElementVector)[i]->GetZasInt());
156 }
157 return (SIGMA > 0.0) ? 1./SIGMA : DBL_MAX;
158}
G4ElementVector
std::vector< G4Element * > G4ElementVector
Definition: G4ElementVector.hh:43
G4GammaConversionToMuons::ComputeCrossSectionPerAtom
G4double ComputeCrossSectionPerAtom(G4double GammaEnergy, G4int Z)
Definition: G4GammaConversionToMuons.cc:174
G4Material::GetElementVector
const G4ElementVector * GetElementVector() const
Definition: G4Material.hh:188
G4Material::GetNumberOfElements
size_t GetNumberOfElements() const
Definition: G4Material.hh:184
G4Material::GetVecNbOfAtomsPerVolume
const G4double * GetVecNbOfAtomsPerVolume() const
Definition: G4Material.hh:204

Referenced by G4GammaGeneralProcess::BuildPhysicsTable(), and GetMeanFreePath().

◆ GetCrossSecFactor()

G4double G4GammaConversionToMuons::GetCrossSecFactor ( ) const
inline

Definition at line 85 of file G4GammaConversionToMuons.hh.

85{ return CrossSecFactor;}

◆ GetCrossSectionPerAtom()

G4double G4GammaConversionToMuons::GetCrossSectionPerAtom ( const G4DynamicParticle *  aDynamicGamma,
const G4Element *  anElement 
)

Definition at line 162 of file G4GammaConversionToMuons.cc.

167{
168 return ComputeCrossSectionPerAtom(aDynamicGamma->GetKineticEnergy(),
169 anElement->GetZasInt());
170}
G4DynamicParticle::GetKineticEnergy
G4double GetKineticEnergy() const
G4Element::GetZasInt
G4int GetZasInt() const
Definition: G4Element.hh:131

◆ GetMeanFreePath()

G4double G4GammaConversionToMuons::GetMeanFreePath ( const G4Track &  aTrack,
G4double  previousStepSize,
G4ForceCondition *  condition 
)
overridevirtual

Implements G4VDiscreteProcess.

Definition at line 113 of file G4GammaConversionToMuons.cc.

119{
120 const G4DynamicParticle* aDynamicGamma = aTrack.GetDynamicParticle();
121 G4double GammaEnergy = aDynamicGamma->GetKineticEnergy();
122 const G4Material* aMaterial = aTrack.GetMaterial();
123
124 MeanFreePath = (GammaEnergy <= LowestEnergyLimit)
125 ? DBL_MAX : ComputeMeanFreePath(GammaEnergy,aMaterial);
126
127 return MeanFreePath;
128}
G4GammaConversionToMuons::ComputeMeanFreePath
G4double ComputeMeanFreePath(G4double GammaEnergy, const G4Material *aMaterial)
Definition: G4GammaConversionToMuons.cc:133
G4Track::GetMaterial
G4Material * GetMaterial() const
G4Track::GetDynamicParticle
const G4DynamicParticle * GetDynamicParticle() const

◆ IsApplicable()

G4bool G4GammaConversionToMuons::IsApplicable ( const G4ParticleDefinition &  part)
overridevirtual

Reimplemented from G4VProcess.

Definition at line 90 of file G4GammaConversionToMuons.cc.

91{
92 return (&part == theGamma);
93}

◆ PostStepDoIt()

G4VParticleChange * G4GammaConversionToMuons::PostStepDoIt ( const G4Track &  aTrack,
const G4Step &  aStep 
)
overridevirtual

Reimplemented from G4VDiscreteProcess.

Definition at line 226 of file G4GammaConversionToMuons.cc.

232{
233 aParticleChange.Initialize(aTrack);
234 const G4Material* aMaterial = aTrack.GetMaterial();
235
236 // current Gamma energy and direction, return if energy too low
237 const G4DynamicParticle *aDynamicGamma = aTrack.GetDynamicParticle();
238 G4double Egam = aDynamicGamma->GetKineticEnergy();
239 if (Egam <= LowestEnergyLimit) {
240 return G4VDiscreteProcess::PostStepDoIt(aTrack,aStep);
241 }
242 //
243 // Kill the incident photon
244 //
245 aParticleChange.ProposeMomentumDirection( 0., 0., 0. ) ;
246 aParticleChange.ProposeEnergy( 0. ) ;
247 aParticleChange.ProposeTrackStatus( fStopAndKill ) ;
248
249 if (Egam <= Energy5DLimit) {
250 std::vector<G4DynamicParticle*> fvect;
251 f5Dmodel->SampleSecondaries(&fvect, aTrack.GetMaterialCutsCouple(),
252 aTrack.GetDynamicParticle(), 0.0, DBL_MAX);
253 aParticleChange.SetNumberOfSecondaries(fvect.size());
254 for(auto dp : fvect) { aParticleChange.AddSecondary(dp); }
255 return G4VDiscreteProcess::PostStepDoIt(aTrack,aStep);
256 }
257
258 G4ParticleMomentum GammaDirection = aDynamicGamma->GetMomentumDirection();
259
260 // select randomly one element constituting the material
261 const G4Element* anElement = SelectRandomAtom(aDynamicGamma, aMaterial);
262 G4int Z = anElement->GetZasInt();
263 G4NistManager* nist = G4NistManager::Instance();
264
265 G4double B,Dn;
266 G4double A027 = nist->GetA27(Z);
267
268 if(Z==1) // special case of Hydrogen
269 { B=202.4;
270 Dn=1.49;
271 }
272 else
273 { B=183.;
274 Dn=1.54*A027;
275 }
276 G4double Zthird=1./nist->GetZ13(Z); // Z**(-1/3)
277 G4double Winfty=B*Zthird*Mmuon/(Dn*electron_mass_c2);
278
279 G4double C1Num=0.138*A027;
280 G4double C1Num2=C1Num*C1Num;
281 G4double C2Term2=electron_mass_c2/(183.*Zthird*Mmuon);
282
283 G4double GammaMuonInv=Mmuon/Egam;
284
285 // generate xPlus according to the differential cross section by rejection
286 G4double xmin=(Egam < LimitEnergy) ? GammaMuonInv : .5-sqrt(.25-GammaMuonInv);
287 G4double xmax=1.-xmin;
288
289 G4double Ds2=(Dn*sqrte-2.);
290 G4double sBZ=sqrte*B*Zthird/electron_mass_c2;
291 G4double LogWmaxInv=1./G4Log(Winfty*(1.+2.*Ds2*GammaMuonInv)
292 /(1.+2.*sBZ*Mmuon*GammaMuonInv));
293 G4double xPlus,xMinus,xPM,result,W;
294 G4int nn = 0;
295 const G4int nmax = 1000;
296 do {
297 xPlus=xmin+G4UniformRand()*(xmax-xmin);
298 xMinus=1.-xPlus;
299 xPM=xPlus*xMinus;
300 G4double del=Mmuon*Mmuon/(2.*Egam*xPM);
301 W=Winfty*(1.+Ds2*del/Mmuon)/(1.+sBZ*del);
302 G4double xxp=1.-4./3.*xPM; // the main xPlus dependence
303 result=(xxp > 0.) ? xxp*G4Log(W)*LogWmaxInv : 0.0;
304 if(result>1.) {
305 G4cout << "G4GammaConversionToMuons::PostStepDoIt WARNING:"
306 << " in dSigxPlusGen, result=" << result << " > 1" << G4endl;
307 }
308 ++nn;
309 if(nn >= nmax) { break; }
310 }
311 // Loop checking, 07-Aug-2015, Vladimir Ivanchenko
312 while (G4UniformRand() > result);
313
314 // now generate the angular variables via the auxilary variables t,psi,rho
315 G4double t;
316 G4double psi;
317 G4double rho;
318
319 G4double a3 = (GammaMuonInv/(2.*xPM));
320 G4double a33 = a3*a3;
321 G4double f1;
322 G4double b1 = 1./(4.*C1Num2);
323 G4double b3 = b1*b1*b1;
324 G4double a21 = a33 + b1;
325
326 G4double f1_max=-(1.-xPM)*(2.*b1+(a21+a33)*G4Log(a33/a21))/(2*b3);
327
328 G4double thetaPlus,thetaMinus,phiHalf; // final angular variables
329 nn = 0;
330 // t, psi, rho generation start (while angle < pi)
331 do {
332 //generate t by the rejection method
333 do {
334 ++nn;
335 t=G4UniformRand();
336 G4double a34=a33/(t*t);
337 G4double a22 = a34 + b1;
338 if(std::abs(b1)<0.0001*a34)
339 // special case of a34=a22 because of logarithm accuracy
340 {
341 f1=(1.-2.*xPM+4.*xPM*t*(1.-t))/(12.*a34*a34*a34*a34);
342 }
343 else
344 {
345 f1=-(1.-2.*xPM+4.*xPM*t*(1.-t))*(2.*b1+(a22+a34)*G4Log(a34/a22))/(2*b3);
346 }
347 if(f1<0.0 || f1> f1_max) // should never happend
348 {
349 G4cout << "G4GammaConversionToMuons::PostStepDoIt WARNING:"
350 << "outside allowed range f1=" << f1
351 << " is set to zero, a34 = "<< a34 << " a22 = "<<a22<<"."
352 << G4endl;
353 f1 = 0.0;
354 }
355 if(nn > nmax) { break; }
356 // Loop checking, 07-Aug-2015, Vladimir Ivanchenko
357 } while ( G4UniformRand()*f1_max > f1);
358 // generate psi by the rejection method
359 G4double f2_max=1.-2.*xPM*(1.-4.*t*(1.-t));
360 // long version
361 G4double f2;
362 do {
363 ++nn;
364 psi=twopi*G4UniformRand();
365 f2=1.-2.*xPM+4.*xPM*t*(1.-t)*(1.+cos(2.*psi));
366 if(f2<0 || f2> f2_max) // should never happend
367 {
368 G4cout << "G4GammaConversionToMuons::PostStepDoIt WARNING:"
369 << "outside allowed range f2=" << f2 << " is set to zero"
370 << G4endl;
371 f2 = 0.0;
372 }
373 if(nn >= nmax) { break; }
374 // Loop checking, 07-Aug-2015, Vladimir Ivanchenko
375 } while ( G4UniformRand()*f2_max > f2);
376
377 // generate rho by direct transformation
378 G4double C2Term1=GammaMuonInv/(2.*xPM*t);
379 G4double C22 = C2Term1*C2Term1+C2Term2*C2Term2;
380 G4double C2=4.*C22*C22/sqrt(xPM);
381 G4double rhomax=(1./t-1.)*1.9/A027;
382 G4double beta=G4Log( (C2+rhomax*rhomax*rhomax*rhomax)/C2 );
383 rho=G4Exp(G4Log(C2 *( G4Exp(beta*G4UniformRand())-1. ))*0.25);
384
385 //now get from t and psi the kinematical variables
386 G4double u=sqrt(1./t-1.);
387 G4double xiHalf=0.5*rho*cos(psi);
388 phiHalf=0.5*rho/u*sin(psi);
389
390 thetaPlus =GammaMuonInv*(u+xiHalf)/xPlus;
391 thetaMinus=GammaMuonInv*(u-xiHalf)/xMinus;
392
393 // protection against infinite loop
394 if(nn > nmax) {
395 if(std::abs(thetaPlus)>pi) { thetaPlus = 0.0; }
396 if(std::abs(thetaMinus)>pi) { thetaMinus = 0.0; }
397 }
398
399 // Loop checking, 07-Aug-2015, Vladimir Ivanchenko
400 } while ( std::abs(thetaPlus)>pi || std::abs(thetaMinus) >pi);
401
402 // now construct the vectors
403 // azimuthal symmetry, take phi0 at random between 0 and 2 pi
404 G4double phi0=twopi*G4UniformRand();
405 G4double EPlus=xPlus*Egam;
406 G4double EMinus=xMinus*Egam;
407
408 // mu+ mu- directions for gamma in z-direction
409 G4ThreeVector MuPlusDirection ( sin(thetaPlus) *cos(phi0+phiHalf),
410 sin(thetaPlus) *sin(phi0+phiHalf), cos(thetaPlus) );
411 G4ThreeVector MuMinusDirection (-sin(thetaMinus)*cos(phi0-phiHalf),
412 -sin(thetaMinus) *sin(phi0-phiHalf), cos(thetaMinus) );
413 // rotate to actual gamma direction
414 MuPlusDirection.rotateUz(GammaDirection);
415 MuMinusDirection.rotateUz(GammaDirection);
416 aParticleChange.SetNumberOfSecondaries(2);
417 // create G4DynamicParticle object for the particle1
418 G4DynamicParticle* aParticle1 =
419 new G4DynamicParticle(theMuonPlus,MuPlusDirection,EPlus-Mmuon);
420 aParticleChange.AddSecondary(aParticle1);
421 // create G4DynamicParticle object for the particle2
422 G4DynamicParticle* aParticle2 =
423 new G4DynamicParticle(theMuonMinus,MuMinusDirection,EMinus-Mmuon);
424 aParticleChange.AddSecondary(aParticle2);
425 // Reset NbOfInteractionLengthLeft and return aParticleChange
426 return G4VDiscreteProcess::PostStepDoIt( aTrack, aStep );
427}
fStopAndKill
@ fStopAndKill
Definition: G4TrackStatus.hh:46
G4int
int G4int
Definition: G4Types.hh:85
G4endl
#define G4endl
Definition: G4ios.hh:57
G4cout
G4GLOB_DLL std::ostream G4cout
C2
const double C2
Definition: MCGIDI_KalbachMann.cc:15
G4UniformRand
#define G4UniformRand()
Definition: Randomize.hh:52
G4BetheHeitler5DModel::SampleSecondaries
void SampleSecondaries(std::vector< G4DynamicParticle * > *fvect, const G4MaterialCutsCouple *couple, const G4DynamicParticle *aDynamicGamma, G4double, G4double) override
Definition: G4BetheHeitler5DModel.cc:280
G4DynamicParticle::GetMomentumDirection
const G4ThreeVector & GetMomentumDirection() const
G4ParticleChange::AddSecondary
void AddSecondary(G4Track *aSecondary)
Definition: G4ParticleChange.cc:187
G4ParticleChange::ProposeEnergy
void ProposeEnergy(G4double finalEnergy)
G4ParticleChange::ProposeMomentumDirection
void ProposeMomentumDirection(G4double Px, G4double Py, G4double Pz)
G4ParticleChange::Initialize
virtual void Initialize(const G4Track &)
Definition: G4ParticleChange.cc:194
G4Track::GetMaterialCutsCouple
const G4MaterialCutsCouple * GetMaterialCutsCouple() const
G4VDiscreteProcess::PostStepDoIt
virtual G4VParticleChange * PostStepDoIt(const G4Track &, const G4Step &)
Definition: G4VDiscreteProcess.cc:120
G4VParticleChange::ProposeTrackStatus
void ProposeTrackStatus(G4TrackStatus status)
G4VParticleChange::SetNumberOfSecondaries
void SetNumberOfSecondaries(G4int totSecondaries)
G4VProcess::aParticleChange
G4ParticleChange aParticleChange
Definition: G4VProcess.hh:327
G4INCL::Math::pi
const G4double pi
Definition: G4INCLGlobals.hh:68

Referenced by G4GammaGeneralProcess::PostStepDoIt().

◆ PrintInfoDefinition()

void G4GammaConversionToMuons::PrintInfoDefinition ( )

Definition at line 460 of file G4GammaConversionToMuons.cc.

461{
462 G4String comments ="gamma->mu+mu- Bethe Heitler process, SubType= ";
463 G4cout << G4endl << GetProcessName() << ": " << comments
464 << GetProcessSubType() << G4endl;
465 G4cout << " good cross section parametrization from "
466 << G4BestUnit(LowestEnergyLimit,"Energy")
467 << " to " << HighestEnergyLimit/GeV << " GeV for all Z." << G4endl;
468}
G4VProcess::GetProcessSubType
G4int GetProcessSubType() const
Definition: G4VProcess.hh:400
G4VProcess::GetProcessName
const G4String & GetProcessName() const
Definition: G4VProcess.hh:382

Referenced by BuildPhysicsTable().

◆ SetCrossSecFactor()

void G4GammaConversionToMuons::SetCrossSecFactor ( G4double  fac)

Definition at line 216 of file G4GammaConversionToMuons.cc.

218{
219 CrossSecFactor=fac;
220 G4cout << "The cross section for GammaConversionToMuons is artificially "
221 << "increased by the CrossSecFactor=" << CrossSecFactor << G4endl;
222}

Referenced by G4EmExtraPhysics::ConstructProcess().

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