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G4CoherentPairProduction Class Reference
#include <G4CoherentPairProduction.hh>
Inheritance diagram for G4CoherentPairProduction:
Additional Inherited Members | |
| Static Public Member Functions inherited from G4VProcess | |
| static const G4String & | GetProcessTypeName (G4ProcessType) |
| 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 47 of file G4CoherentPairProduction.hh.
Constructor & Destructor Documentation
◆ G4CoherentPairProduction()
| G4CoherentPairProduction::G4CoherentPairProduction | ( | const G4String & | processName = "cpp", |
| G4ProcessType | aType = fElectromagnetic ) |
Definition at line 50 of file G4CoherentPairProduction.cc.
51 :
52 G4VDiscreteProcess(aName)
53{
55}
G4VDiscreteProcess(const G4String &aName, G4ProcessType aType=fNotDefined)
Definition G4VDiscreteProcess.cc:51
◆ ~G4CoherentPairProduction()
|
default |
Member Function Documentation
◆ ActivateIncoherentScattering()
|
inline |
activate incoherent scattering (standard gamma conversion should be switched off in physics list)
Definition at line 79 of file G4CoherentPairProduction.hh.
79{fIncoherentScattering = true;}
Referenced by G4CoherentPairProductionPhysics::ConstructProcess().
◆ GetChargeParticleAngleFactor()
|
inline |
get the number of particle angles 1/gamma in pair production defining the width of the angular distribution of pair sampling in the Baier-Katkov Integral
Definition at line 96 of file G4CoherentPairProduction.hh.
96{return fChargeParticleAngleFactor;}
◆ GetCrystalData()
|
inline |
Definition at line 81 of file G4CoherentPairProduction.hh.
81{return fCrystalData;}
◆ GetEffectiveLrad()
|
inline |
get effective radiation length (due to coherent process of pair production) simulated for the current photon
Definition at line 104 of file G4CoherentPairProduction.hh.
104{return fEffectiveLrad;}
◆ GetG4RegionName()
|
inline |
get the name of G4Region in which the model is applicable
Definition at line 107 of file G4CoherentPairProduction.hh.
107{return fG4RegionName;}
◆ GetHighAngleLimit()
|
inline |
Definition at line 86 of file G4CoherentPairProduction.hh.
86{return fHighAngleLimit;}
Referenced by GetMeanFreePath().
◆ GetMeanFreePath()
|
overridevirtual |
Implements G4VDiscreteProcess.
Definition at line 59 of file G4CoherentPairProduction.cc.
62{
63 //current logical volume
64 G4LogicalVolume* crystallogic;
65
66 //momentum direction and coordinates (see comments below)
67 G4ThreeVector momentumDirectionGamma,xyzGamma0,xyzGamma;
68 //angle of the photon in the local reference system of the volume
69 G4double txGamma0 = 0, tyGamma0 = 0;
70
72
73 //model activation
75
76 //photon energy
78
79 //energy cut, at the beginning, to not check everything else
81 {
82 //current logical volume
84
85 //the model works only in the G4Region fG4RegionName
87 {
88 fCrystalData->SetGeometryParameters(crystallogic);
89
90 //the momentum direction of the photon in the local reference system of the volume
91 momentumDirectionGamma =
92 (aTrack.GetTouchableHandle()->GetHistory()->
93 GetTopTransform().NetRotation().inverse())*aTrack.GetMomentumDirection();
94
95 //the coordinates of the photon in the local reference system of the volume
96 xyzGamma0 =
98 GetTopTransform().TransformPoint(aTrack.GetPosition());
99
100 // the coordinates of the photon in the co-rotating reference system within
101 //a channel (elementary periodic cell)
102 xyzGamma = fCrystalData->CoordinatesFromBoxToLattice(xyzGamma0);
103
104 //angle of the photon in the local reference system of the volume
105 //(!!! ONLY FORWARD DIRECTION, momentumDirectionGamma.getZ()>0,
108
109 //recalculate angle into the lattice reference system
111 if (fCrystalData->GetModel()==2)
112 {
113 angle = std::sqrt(angle*angle+tyGamma0*tyGamma0);
114 }
115
116 //Applies the parameterisation not at the last step, only forward local direction
117 //above low energy limit and below angular limit
118 modelTrigger = (momentumDirectionGamma.z()>0. &&
119 std::abs(angle) < GetHighAngleLimit());
120 }
121 }
122
123 if(modelTrigger)
124 {
125 //execute the model
126
128 //in the co-rotating reference system within
129 //a channel (elementary periodic cell)
131 // in the local reference system of the volume
133 // in the co-rotating reference system within
134 //a channel (elementary periodic cell)
135
137
138 //coordinates in Runge-Kutta calculations
139 G4double x1=0.,x2=0.,x3=0.,x4=0.,y1=0.,y2=0.,y3=0.,y4=0.;
140 //angles in Runge-Kutta calculations
141 G4double tx1=0.,tx2=0.,tx3=0.,tx4=0.,ty1=0.,ty2=0.,ty3=0.,ty4=0.;
142 //variables in Runge-Kutta calculations
143 G4double kvx1=0.,kvx2=0.,kvx3=0.,kvx4=0.,kvy1=0.,kvy2=0.,kvy3=0.,kvy4=0.;
144 //simulation step along z (internal step of the model) and its parts
146 //simulation step along the momentum direction
147 G4double momentumDirectionStep;
148 //effective simulation step (taking into account nuclear density along the trajectory)
149 G4double effectiveStep=0.;
150
151 // Baier-Katkov variables
156
157 G4double dzmod=0.;
158 G4double fa1=0.,faseBefore=0.,faseBeforedz=0.,faseBeforedzd2=0.;
159 G4double faseAfter=0.,fa2dfaseBefore2=0.;
160
161 G4double skJ=0, skIx=0., skIy=0.;
162 G4double sinfa1=0.,cosfa1=0.;
163
164 //2-vector is needed for an initial parameter collection of 1 pair
165 //vector of 2-vectors is an initial parameter collection of all sampling pair
166
167 //collection of etotal for a single pair
168 CLHEP::Hep2Vector twoVectorEtotal(0.,0.);
169
170 //collection of x for a single pair
171 CLHEP::Hep2Vector twoVectorX(0.,0.);
172
173 //collection of y for a single pair
174 CLHEP::Hep2Vector twoVectorY(0.,0.);
175
176 //collection of tx for a single pair
177 CLHEP::Hep2Vector twoVectorTX(0.,0.);
178
179 //collection of tx for a single pair
180 CLHEP::Hep2Vector twoVectorTY(0.,0.);
181
182 fullVectorEtotal.clear();
183 fullVectorX.clear();
184 fullVectorY.clear();
185 fullVectorTX.clear();
186 fullVectorTY.clear();
187 fPairProductionCDFdz.clear();
188 fPairProductionCDFdz.push_back(0.);//0th element equal to 0
189
191 const G4String particleName[2] = {"e-", "e+"};
192
193 // the coordinates of a charged particle in the reference system within
194 //a channel (elementary periodic cell)
196
197 //the idea of pair production simulation is analogical to radiation in G4BaierKatkov
198 //since the matrix element of these processes is the same => we solve inverse problem
199 //to radiation: sample the pairs, calculate their trajectories and then calculate the
200 //probabilities using Baier-Katkov analogically to radiation
201
202 //cycle by sampling e+- pairs
204 {
205 //pair energy uniform sampling
206 G4double etotal = fMass + fPPKineticEnergyCut +
208 //total energy
209
211
212 //the probability of the production of the current pair (will be simulated)
213 //per distance
214 G4double probabilityPPdz = 0.;
215
216 //cycle e- and e+ within single pair
218 {
219 if(j==1){etotal=eGamma-etotal;} //2nd particle energy
220 twoVectorEtotal[j]=etotal;
221
222 //Baier-Katkov input
223 //intermediate variables to reduce calculations (the same names as in G4BaierKatkov)
224 G4double e2 = etotal*etotal;
226 //normalization coefficient
227 G4double coefNorm = CLHEP::fine_structure_const/(8*(CLHEP::pi2))/(2.*fNMCPairs);
228 //G4double phi = CLHEP::twopi*G4UniformRand();//necessary for pair kinematics
231 G4double eprime2 = eprime*eprime;
232 G4double e2pluseprime2 =e2+eprime2;
234 G4double omprimed2=omprime/2;
235
236 //difference vs G4BaierKatkov: om -> etotal
238
240
241 //initialize intermediate integrals with zeros
242 G4double fa=0.,ss=0.,sc=0.,ssx=0.,ssy=0.,scx=0.,scy=0.;
243
244 //End of Baier-Katkov input
245
247
248 //set fCrystalData parameters depending on the particle parameters
249 fCrystalData->SetParticleProperties(etotal, fMass,
250 charge[j], particleName[j]);
251
252 //needed just to setup the correct value of channel No in the crystal
253 //since later it may be changed during the trajectory calculation
254 fCrystalData->CoordinatesFromBoxToLattice(xyzGamma0);
255
256 //coordinate sampling: random x and y due to coordinate uncertainty
257 //in the interaction point
258 if(j==0)
259 {
260 x = fCrystalData->GetChannelWidthX()*G4UniformRand();
261 y = fCrystalData->GetChannelWidthY()*G4UniformRand();
262 }
263 else
264 {
265 x=twoVectorX[0];
266 y=twoVectorY[0];
267 }
268 twoVectorX[j] = x;
269 twoVectorY[j] = y;
270 //definite z as a coordinate of the photon (uncertainty of the
271 //interaction point is taking into account later by simulation
272 //of the position of pair production)
273 z = xyzGamma.z();
274
275 //angles of the photon in the co-rotating reference system within a channel =>
276 //angular distribution center
277 G4double tx = fCrystalData->AngleXFromBoxToLattice(txGamma0,z);
278 G4double ty = tyGamma0;
279 G4double momentumDirectionZGamma = 1./
280 std::sqrt(1.+std::pow(std::tan(tx),2)+
281 std::pow(std::tan(ty),2));
282
283 //angle sampling: depends on angular range within a particle trajectory
284 //defined by the Lindhard angle and on the angle of radiation proportional
285 //to 1/gamma
286
287 //range of MC integration on angles
288 G4double paramParticleAngle = fChargeParticleAngleFactor*fMass/etotal;
289
290 G4double axangle=0.;
291 if (fCrystalData->GetModel()==1)//1D model (only angle vs plane matters)
292 {
293 axangle = std::abs(tx);
294 }
295 else if (fCrystalData->GetModel()==2)//2D model
296 {
297 axangle = std::sqrt(tx*tx+ty*ty);
298 }
299
301 {
302 paramParticleAngle+=axangle
303 -std::sqrt(axangle*axangle
304 -fCrystalData->GetLindhardAngle()
305 *fCrystalData->GetLindhardAngle());
306 }
307 else
308 {
309 paramParticleAngle+=fCrystalData->GetLindhardAngle();
310 }
311
312
313 //ONLY forward direction
315
316 G4double rho=1.;
318 //the distribution
319 G4double norm=std::atan(rhocut*rhocut)*
320 CLHEP::pi*paramParticleAngle*paramParticleAngle;
321
322
323 //distribution with long tails (useful to not exclude particle angles
324 //after a strong single scattering)
325 //at ellipsescale < 1 => half of statistics
326 do
327 {
328 rho = std::sqrt(std::tan(CLHEP::halfpi*G4UniformRand()));
329 }
330 while (rho>rhocut);
331
332 //normalization coefficient for intergration on angles of charged particles
333 G4double angleNormCoef = (1.+rho*rho*rho*rho)*norm;
334
335 tx+=charge[j]*paramParticleAngle*rho*std::cos(phi);
336 twoVectorTX[j] = tx;
337 ty+=charge[j]*paramParticleAngle*rho*std::sin(phi);
338 twoVectorTY[j] = ty;
339
341 //depending on the trajectory length along Gamma direction
342 //starting the trajectory
343 //here we don't care about the boundaries of the crystal volume
344 //the trajectory is very short and the pair production probability obtained
345 //in Baier-Katkov will be extrapolated to the real step inside the crystal volume
347 {
348 //back to the local reference system of the volume
349 txPreStep0 = fCrystalData->AngleXFromLatticeToBox(tx,z);
350 tyPreStep0 = ty;
351
352 dz = fCrystalData->GetSimulationStep(tx,ty);
353 dzd3=dz/3;
354 dzd8=dz/8;
355
356 //trajectory calculation:
357 //Runge-Cutt "3/8"
358 //fCrystalData->GetCurv(z)*fCrystalData->GetCorrectionZ() is due to dependence
359 //of the radius on x; GetCurv gets 1/R for the central ("central plane/axis")
360
361 //first step
362 kvx1=fCrystalData->Ex(x,y);
363 x1=x+tx*dzd3;
364 tx1=tx+(kvx1-fCrystalData->GetCurv(z)*fCrystalData->GetCorrectionZ())*dzd3;
365 if (fCrystalData->GetModel()==2)
366 {
367 kvy1=fCrystalData->Ey(x,y);
368 y1=y+ty*dzd3;
369 ty1=ty+kvy1*dzd3;
370 }
371
372 //second step
373 kvx2=fCrystalData->Ex(x1,y1);
374 x2=x-tx*dzd3+tx1*dz;
375 tx2=tx-(kvx1-fCrystalData->GetCurv(z)*fCrystalData->GetCorrectionZ())*dzd3+
376 (kvx2-fCrystalData->GetCurv(z)*fCrystalData->GetCorrectionZ())*dz;
377 if (fCrystalData->GetModel()==2)
378 {
379 kvy2=fCrystalData->Ey(x1,y1);
380 y2=y-ty*dzd3+ty1*dz;
381 ty2=ty-kvy1*dzd3+kvy2*dz;
382 }
383
384 //third step
385 kvx3=fCrystalData->Ex(x2,y2);
386 x3=x+(tx-tx1+tx2)*dz;
387 tx3=tx+(kvx1-kvx2+kvx3-
388 fCrystalData->GetCurv(z)*fCrystalData->GetCorrectionZ())*dz;
389 if (fCrystalData->GetModel()==2)
390 {
391 kvy3=fCrystalData->Ey(x2,y2);
392 y3=y+(ty-ty1+ty2)*dz;
393 ty3=ty+(kvy1-kvy2+kvy3)*dz;
394 }
395
396 //fourth step
397 kvx4=fCrystalData->Ex(x3,y3);
398 x4=x+(tx+3.*tx1+3.*tx2+tx3)*dzd8;
399 tx4=tx+(kvx1+3.*kvx2+3.*kvx3+kvx4)*dzd8-
400 fCrystalData->GetCurv(z)*fCrystalData->GetCorrectionZ()*dz;
401 if (fCrystalData->GetModel()==2)
402 {
403 kvy4=fCrystalData->Ey(x3,y3);
404 y4=y+(ty+3.*ty1+3.*ty2+ty3)*dzd8;
405 ty4=ty+(kvy1+3.*kvy2+3.*kvy3+kvy4)*dzd8;
406 }
407 else
408 {
409 y4 =y+ty*dz;
410 ty4=ty;
411 }
412
413 x=x4;
414 tx=tx4;
415 y=y4;
416 ty=ty4;
417
418 z+=dz*fCrystalData->GetCorrectionZ();//motion along the z coordinate
419 //("central plane/axis", no current plane/axis)
420
421 xyzparticle = fCrystalData->ChannelChange(x,y,z);
422 x=xyzparticle.x();
423 y=xyzparticle.y();
424 z=xyzparticle.z();
425
426 momentumDirectionStep =
427 dz*std::sqrt(1+std::pow(std::tan(tx),2)+std::pow(std::tan(ty),2));
428 zalongGamma += dz/momentumDirectionZGamma;
429
430 //default scattering and energy loss 0
431 scatteringAnglesAndEnergyLoss.set(0.,0.,0.);
432
433 if(fIncoherentScattering)
434 {
435 //calculate separately for each element of the crystal
437 {
438 //effective step taking into account nuclear density along the trajectory
439 effectiveStep = momentumDirectionStep*
440 fCrystalData->NuclearDensity(x,y,ii);
441 //Coulomb scattering on screened atomic potential
442 //(both multiple and single)
443 scatteringAnglesAndEnergyLoss +=
444 fCrystalData->CoulombAtomicScattering(effectiveStep,
445 momentumDirectionStep,
446 ii);
447 }
448 //electron scattering and coherent part of ionization energy losses
449 scatteringAnglesAndEnergyLoss += fCrystalData->CoulombElectronScattering(
450 fCrystalData->MinIonizationEnergy(x,y),
451 fCrystalData->ElectronDensity(x,y),
452 momentumDirectionStep);
453 tx += scatteringAnglesAndEnergyLoss.x();
454 ty += scatteringAnglesAndEnergyLoss.y();
455 }
456
457 //To avoid backward direction
459 std::abs(ty)>CLHEP::halfpi-DBL_EPSILON)
460 {
463 fbreak = true;
464 break;
465 }
466
467 //**********Baier-Katkov start
468
469 //back to the local reference system of the volume
470 tx0 = fCrystalData->AngleXFromLatticeToBox(tx,z);
471 ty0 = ty;
472
473 dzMeV=momentumDirectionStep/CLHEP::hbarc;// in MeV^-1
474
475 // accelerations
476 axt=(tx0-scatteringAnglesAndEnergyLoss.x()-txPreStep0)/dzMeV;
477 ayt=(ty0-scatteringAnglesAndEnergyLoss.y()-tyPreStep0)/dzMeV;
478
479 //the angles vs the photon (with incoherent scattering)
480 vxin = tx0-txGamma0;
481 vyin = ty0-tyGamma0;
482 //the angles vs the photon (without incoherent scattering)
483 vxno = vxin-scatteringAnglesAndEnergyLoss.x();
484 vyno = vyin-scatteringAnglesAndEnergyLoss.y();
485
486 //phase difference before scattering
487 faseBefore=omprimed2*(gammaInverse2+vxno*vxno+vyno*vyno);//phi' t<ti//MeV
488
489 faseBeforedz = faseBefore*dzMeV;
490 faseBeforedzd2 = faseBeforedz/2.;
491 fa+=faseBeforedz; //
492 fa1=fa-faseBeforedzd2;//
493 dzmod=2*std::sin(faseBeforedzd2)/faseBefore;//MeV^-1
494
495 //phi''/faseBefore^2
496 fa2dfaseBefore2 = omprime*(axt*vxno+ayt*vyno)/(faseBefore*faseBefore);
497
498 //phase difference after scattering
499 faseAfter=omprimed2*(gammaInverse2+vxin*vxin+vyin*vyin);//phi' ti+O//MeV
500
501 skJ=1/faseAfter-1/faseBefore-fa2dfaseBefore2*dzmod;//MeV^-1
502 skIx=vxin/faseAfter-vxno/faseBefore+dzmod*(axt/faseBefore-
503 vxno*fa2dfaseBefore2);
504 skIy=vyin/faseAfter-vyno/faseBefore+dzmod*(ayt/faseBefore-
505 vyno*fa2dfaseBefore2);
506
507 sinfa1 = std::sin(fa1);
508 cosfa1 = std::cos(fa1);
509
510 ss+=sinfa1*skJ;//sum sin integral J of BK
511 sc+=cosfa1*skJ;//sum cos integral J of BK
512 ssx+=sinfa1*skIx;// sum sin integral Ix of BK
513 ssy+=sinfa1*skIy;// sum sin integral Iy of BK
514 scx+=cosfa1*skIx;// sum cos integral Ix of BK
515 scy+=cosfa1*skIy;// sum cos integral Iy of BK
516 }
517
518 //only of the trajectory cycle was not broken
519 if(!fbreak)
520 {
523
524 probabilityPPdz += coefNorme2deprime2*angleNormCoef*
525 (i2*e2pluseprime2+j2*gammaInverse2om)/zalongGamma;
526 }
527 }
528
529 //filling the CDF of probabilities of the production of sampling pairs
530 fPairProductionCDFdz.push_back(fPairProductionCDFdz[i]+probabilityPPdz);
531 //**********Baier-Katkov end
532
533 //accumulation of initial parameters of sampling pairs
534 fullVectorEtotal.push_back(twoVectorEtotal);
535 fullVectorX.push_back(twoVectorX);
536 fullVectorY.push_back(twoVectorY);
537 fullVectorTX.push_back(twoVectorTX);
538 fullVectorTY.push_back(twoVectorTY);
539 }
540
541 //photon mean free path
542 //fPairProductionCDFdz.back() = full pair production probability
543 //simulated for the current photon along photon direction
544 G4double lMeanFreePath = 1/fPairProductionCDFdz.back();
545
546 fEffectiveLrad = 7.*lMeanFreePath/9.;//only for scoring purpose
547
548 return lMeanFreePath;
549 }
550 else
551 {
552 //dummy process, does not occur
554 }
555
556}
G4double condition(const G4ErrorSymMatrix &m)
G4GLOB_DLL std::ostream G4cout
double z() const
double x() const
double y() const
void set(double x, double y, double z)
G4double GetHighAngleLimit()
Definition G4CoherentPairProduction.hh:86
G4Region * GetRegion() const
const G4String & GetName() const
virtual const G4NavigationHistory * GetHistory() const
G4VPhysicalVolume * GetVolume() const
const G4ThreeVector & GetPosition() const
const G4TouchableHandle & GetTouchableHandle() const
const G4ThreeVector & GetMomentumDirection() const
G4double GetTotalEnergy() const
G4LogicalVolume * GetLogicalVolume() const
◆ GetNTrajectorySteps()
|
inline |
get number of trajectory steps of a single particle (e- or e+)
Definition at line 99 of file G4CoherentPairProduction.hh.
99{return fNTrajectorySteps;}
◆ GetPPKineticEnergyCut()
|
inline |
Definition at line 87 of file G4CoherentPairProduction.hh.
87{return fPPKineticEnergyCut;}
◆ GetSamplingPairsNumber()
|
inline |
get the number of pairs in sampling of Baier-Katkov Integral (MC integration by e+- energy and angles <=> e+- momentum)
Definition at line 91 of file G4CoherentPairProduction.hh.
91{return fNMCPairs;}
◆ Input() [1/3]
| void G4CoherentPairProduction::Input | ( | const G4ChannelingFastSimCrystalData * | crystalData | ) |
Definition at line 674 of file G4CoherentPairProduction.cc.
675{
676 //setting the class with containing all
677 //the crystal material and crystal lattice data and
678 //Channeling scattering and ionization processes
679 //fCrystalData = new G4ChannelingFastSimCrystalData();
680
681 fCrystalData = const_cast<G4ChannelingFastSimCrystalData*>(crystalData);
682}
◆ Input() [2/3]
|
inline |
special functions
Definition at line 66 of file G4CoherentPairProduction.hh.
void Input(const G4Material *crystal, const G4String &lattice)
special functions
Definition G4CoherentPairProduction.hh:66
Referenced by G4CoherentPairProductionPhysics::ConstructProcess(), and Input().
◆ Input() [3/3]
| void G4CoherentPairProduction::Input | ( | const G4Material * | crystal, |
| const G4String & | lattice, | ||
| const G4String & | filePath ) |
Definition at line 660 of file G4CoherentPairProduction.cc.
663{
664 //initializing the class with containing all
665 //the crystal material and crystal lattice data and
666 //Channeling scattering and ionization processes
667 fCrystalData = new G4ChannelingFastSimCrystalData();
668 //setting all the crystal material and lattice data
669 fCrystalData->SetMaterialProperties(crystal,lattice,filePath);
670}
◆ IsApplicable()
|
inlineoverridevirtual |
Reimplemented from G4VProcess.
Definition at line 57 of file G4CoherentPairProduction.hh.
◆ ModelMinPrimaryEnergy()
|
inline |
get cuts
Definition at line 85 of file G4CoherentPairProduction.hh.
85{ return fLowEnergyLimit;}
Referenced by GetMeanFreePath().
◆ PostStepDoIt()
|
overridevirtual |
Reimplemented from G4VDiscreteProcess.
Definition at line 560 of file G4CoherentPairProduction.cc.
562{
563 //example with no physical sense
564 aParticleChange.Initialize(aTrack);
565 //G4LogicalVolume* aLV = aTrack.GetVolume()->GetLogicalVolume();
566
567 const G4ParticleDefinition* chargedParticleDefinition[2] =
569
570 // the coordinates of the photon in the local reference system of the volume
571 G4ThreeVector xyzGamma0 =
573 GetTopTransform().TransformPoint(aTrack.GetPosition());
574
575 // the coordinates of the photon in the co-rotating reference system within
576 //a channel (elementary periodic cell)
577 G4ThreeVector xyzGamma = fCrystalData->CoordinatesFromBoxToLattice(xyzGamma0);
578
579 //global time
581
583
584 //randomly choosing the pair to be produced from the sampling list
585 //according to the probabilities calculated in the Baier-Katkov integral
587 //a pair produced
588
589 // the coordinates of a charged particle in the reference system within
590 //a channel (elementary periodic cell)
591 G4ThreeVector xyzparticle;
592 //cycle e- and e+ within single pair
594 {
596
597 //in the local reference system of the volume
598 G4ThreeVector newParticleCoordinateXYZ =
599 fCrystalData->CoordinatesFromLatticeToBox(xyzparticle);
600 //the same in the global reference system
601 newParticleCoordinateXYZ =
603 GetTopTransform().Inverse().TransformPoint(newParticleCoordinateXYZ);
604
605 //back to the local reference system of the volume
607 G4double ty0 = fullVectorTY[ipair][j];
608
609 G4double momentumDirectionZ = 1./
610 std::sqrt(1.+std::pow(std::tan(tx0),2)+
611 std::pow(std::tan(ty0),2));
612
613 //momentum direction vector of the charged particle produced
614 //in the local reference system of the volume
616 momentumDirectionZ*std::tan(ty0),
617 momentumDirectionZ);
618 //the same in the global reference system
619 momentumDirectionParticle =
620 (aTrack.GetTouchableHandle()->GetHistory()->GetTopTransform().NetRotation()) *
621 momentumDirectionParticle;
622
623 G4DynamicParticle* chargedParticle =
624 new G4DynamicParticle(chargedParticleDefinition[j],
625 momentumDirectionParticle,
626 fullVectorEtotal[ipair][j]-fMass);
627
628 // Create the track for the secondary particle
629 G4Track* secondaryTrack = new G4Track(chargedParticle,
630 tGlobalGamma,
631 newParticleCoordinateXYZ);
634
635 //generation of a secondary charged particle
636 aParticleChange.AddSecondary(secondaryTrack);
637 }
638
639 //killing the photon
641
643}
const G4TouchableHandle & GetTouchableHandle() const
G4StepPoint * GetPostStepPoint() const
G4int GetTrackID() const
void SetTouchableHandle(const G4TouchableHandle &apValue)
G4double GetGlobalTime() const
void SetParentID(const G4int aValue)
◆ ProcessDescription()
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overridevirtual |
Reimplemented from G4VProcess.
Definition at line 686 of file G4CoherentPairProduction.cc.
687{
688 out << " Coherent pair production";
689 G4VDiscreteProcess::ProcessDescription(out);
690}
virtual void ProcessDescription(std::ostream &outfile) const
Definition G4VProcess.cc:181
◆ SetChargeParticleAngleFactor()
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inline |
set the number of particle angles 1/gamma in pair production defining the width of the angular distribution of pair sampling in the Baier-Katkov Integral
Definition at line 121 of file G4CoherentPairProduction.hh.
122 {fChargeParticleAngleFactor = chargeParticleAngleFactor;}
Referenced by G4CoherentPairProductionPhysics::ConstructProcess().
◆ SetG4RegionName()
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inline |
set the name of G4Region in which the model is applicable
Definition at line 129 of file G4CoherentPairProduction.hh.
129{fG4RegionName=nameG4Region;}
Referenced by G4CoherentPairProductionPhysics::ConstructProcess().
◆ SetHighAngleLimit()
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inline |
Definition at line 111 of file G4CoherentPairProduction.hh.
111{fHighAngleLimit=angle;}
Referenced by G4CoherentPairProductionPhysics::ConstructProcess().
◆ SetLowEnergyLimit()
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inline |
set cuts
Definition at line 110 of file G4CoherentPairProduction.hh.
110{fLowEnergyLimit=energy;}
G4double energy(const ThreeVector &p, const G4double m)
Definition G4INCLKinematicsUtils.cc:185
Referenced by G4CoherentPairProductionPhysics::ConstructProcess().
◆ SetNTrajectorySteps()
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inline |
set number of trajectory steps of a single particle (e- or e+)
Definition at line 125 of file G4CoherentPairProduction.hh.
126 {fNTrajectorySteps = nTrajectorySteps;}
Referenced by G4CoherentPairProductionPhysics::ConstructProcess().
◆ SetPPKineticEnergyCut()
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inline |
Definition at line 112 of file G4CoherentPairProduction.hh.
112{fPPKineticEnergyCut=kineticEnergyCut;}
Referenced by G4CoherentPairProductionPhysics::ConstructProcess().
◆ SetSamplingPairsNumber()
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inline |
set the number of pairs in sampling of Baier-Katkov Integral (MC integration by e+- energy and angles <=> e+- momentum)
Definition at line 116 of file G4CoherentPairProduction.hh.
116{fNMCPairs = nPairs;}
Referenced by G4CoherentPairProductionPhysics::ConstructProcess().
The documentation for this class was generated from the following files:
