Geant4_10
G4SynchrotronRadiation.cc
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27 // $Id: G4SynchrotronRadiation.cc 74582 2013-10-15 12:06:25Z gcosmo $
28 //
29 // --------------------------------------------------------------
30 // GEANT 4 class implementation file
31 // CERN Geneva Switzerland
32 //
33 // History: first implementation,
34 // 21-5-98 V.Grichine
35 // 28-05-01, V.Ivanchenko minor changes to provide ANSI -wall compilation
36 // 04.03.05, V.Grichine: get local field interface
37 // 18-05-06 H. Burkhardt: Energy spectrum from function rather than table
38 //
39 //
40 //
41 //
43 
45 #include "G4PhysicalConstants.hh"
46 #include "G4SystemOfUnits.hh"
47 #include "G4UnitsTable.hh"
48 #include "G4EmProcessSubType.hh"
49 #include "G4DipBustGenerator.hh"
50 #include "G4Log.hh"
51 
53 //
54 // Constructor
55 //
56 
58  G4ProcessType type):G4VDiscreteProcess (processName, type),
59  theGamma (G4Gamma::Gamma() ),
60  theElectron ( G4Electron::Electron() ),
61  thePositron ( G4Positron::Positron() )
62 {
63  G4TransportationManager* transportMgr =
65 
66  fFieldPropagator = transportMgr->GetPropagatorInField();
67 
68  fLambdaConst = std::sqrt(3.0)*electron_mass_c2/
70  fEnergyConst = 1.5*c_light*c_light*eplus*hbar_Planck/electron_mass_c2 ;
71 
73  verboseLevel = 1;
74  FirstTime = true;
75  FirstTime1 = true;
76  genAngle = 0;
78 }
79 
81 //
82 // Destructor
83 //
84 
86 {
87  delete genAngle;
88 }
89 
91 //
92 
93 void
95 {
96  if(p != genAngle) {
97  delete genAngle;
98  genAngle = p;
99  }
100 }
101 
102 G4bool
104 {
105  return ( ( &particle == theElectron ) || ( &particle == thePositron ));
106 }
107 
109 //
110 // Production of synchrotron X-ray photon
111 // GEANT4 internal units.
112 //
113 
114 G4double
116  G4double,
118 {
119  // gives the MeanFreePath in GEANT4 internal units
120  G4double MeanFreePath;
121 
122  const G4DynamicParticle* aDynamicParticle = trackData.GetDynamicParticle();
123 
124  *condition = NotForced;
125 
126  G4double gamma = aDynamicParticle->GetTotalEnergy()/
127  aDynamicParticle->GetMass();
128 
129  G4double particleCharge = aDynamicParticle->GetDefinition()->GetPDGCharge();
130 
131  if ( gamma < 1.0e3 || 0.0 == particleCharge) { MeanFreePath = DBL_MAX; }
132  else
133  {
134 
135  G4ThreeVector FieldValue;
136  const G4Field* pField = 0;
137  G4bool fieldExertsForce = false;
138 
139 
140  G4FieldManager* fieldMgr =
141  fFieldPropagator->FindAndSetFieldManager(trackData.GetVolume());
142 
143  if ( fieldMgr != 0 )
144  {
145  // If the field manager has no field, there is no field !
146 
147  fieldExertsForce = ( fieldMgr->GetDetectorField() != 0 );
148  }
149 
150  if ( fieldExertsForce )
151  {
152  pField = fieldMgr->GetDetectorField();
153  G4ThreeVector globPosition = trackData.GetPosition();
154 
155  G4double globPosVec[4], FieldValueVec[6];
156 
157  globPosVec[0] = globPosition.x();
158  globPosVec[1] = globPosition.y();
159  globPosVec[2] = globPosition.z();
160  globPosVec[3] = trackData.GetGlobalTime();
161 
162  pField->GetFieldValue( globPosVec, FieldValueVec );
163 
164  FieldValue = G4ThreeVector( FieldValueVec[0],
165  FieldValueVec[1],
166  FieldValueVec[2] );
167 
168  G4ThreeVector unitMomentum = aDynamicParticle->GetMomentumDirection();
169  G4ThreeVector unitMcrossB = FieldValue.cross(unitMomentum);
170  G4double perpB = unitMcrossB.mag();
171 
172  if( perpB > 0.0 ) MeanFreePath = fLambdaConst/perpB;
173  else MeanFreePath = DBL_MAX;
174 
175  if(verboseLevel > 0 && FirstTime)
176  {
177  G4cout << "G4SynchrotronRadiation::GetMeanFreePath :" << '\n'
178  << " MeanFreePath = " << G4BestUnit(MeanFreePath, "Length")
179  << G4endl;
180  if(verboseLevel > 1)
181  {
182  G4ThreeVector pvec = aDynamicParticle->GetMomentum();
183  G4double Btot = FieldValue.getR();
184  G4double ptot = pvec.getR();
185  G4double rho = ptot / (MeV * c_light * Btot );
186  // full bending radius
187  G4double Theta=unitMomentum.theta(FieldValue);
188  // angle between particle and field
189  G4cout << " B = " << Btot/tesla << " Tesla"
190  << " perpB = " << perpB/tesla << " Tesla"
191  << " Theta = " << Theta << " std::sin(Theta)="
192  << std::sin(Theta) << '\n'
193  << " ptot = " << G4BestUnit(ptot,"Energy")
194  << " rho = " << G4BestUnit(rho,"Length")
195  << G4endl;
196  }
197  FirstTime=false;
198  }
199  }
200  else MeanFreePath = DBL_MAX;
201 
202  }
203 
204  return MeanFreePath;
205 }
206 
208 //
209 //
210 
213  const G4Step& stepData )
214 
215 {
216  aParticleChange.Initialize(trackData);
217 
218  const G4DynamicParticle* aDynamicParticle = trackData.GetDynamicParticle();
219 
220  G4double gamma = aDynamicParticle->GetTotalEnergy()/
221  (aDynamicParticle->GetMass() );
222 
223  G4double particleCharge = aDynamicParticle->GetDefinition()->GetPDGCharge();
224  if(gamma <= 1.0e3 || 0.0 == particleCharge)
225  {
226  return G4VDiscreteProcess::PostStepDoIt(trackData,stepData);
227  }
228 
229  G4ThreeVector FieldValue;
230  const G4Field* pField = 0;
231 
232  G4bool fieldExertsForce = false;
233  G4FieldManager* fieldMgr =
234  fFieldPropagator->FindAndSetFieldManager(trackData.GetVolume());
235 
236  if ( fieldMgr != 0 )
237  {
238  // If the field manager has no field, there is no field !
239  fieldExertsForce = ( fieldMgr->GetDetectorField() != 0 );
240  }
241 
242  if ( fieldExertsForce )
243  {
244  pField = fieldMgr->GetDetectorField();
245  G4ThreeVector globPosition = trackData.GetPosition();
246  G4double globPosVec[4], FieldValueVec[6];
247  globPosVec[0] = globPosition.x();
248  globPosVec[1] = globPosition.y();
249  globPosVec[2] = globPosition.z();
250  globPosVec[3] = trackData.GetGlobalTime();
251 
252  pField->GetFieldValue( globPosVec, FieldValueVec );
253  FieldValue = G4ThreeVector( FieldValueVec[0],
254  FieldValueVec[1],
255  FieldValueVec[2] );
256 
257  G4ThreeVector unitMomentum = aDynamicParticle->GetMomentumDirection();
258  G4ThreeVector unitMcrossB = FieldValue.cross(unitMomentum);
259  G4double perpB = unitMcrossB.mag();
260  if(perpB > 0.0)
261  {
262  // M-C of synchrotron photon energy
263 
264  G4double energyOfSR = GetRandomEnergySR(gamma,perpB);
265 
266  // check against insufficient energy
267 
268  if( energyOfSR <= 0.0 )
269  {
270  return G4VDiscreteProcess::PostStepDoIt(trackData,stepData);
271  }
272  G4double kineticEnergy = aDynamicParticle->GetKineticEnergy();
273  G4ThreeVector gammaDirection =
274  genAngle->SampleDirection(aDynamicParticle,
275  energyOfSR, 1, 0);
276 
277  G4ThreeVector gammaPolarization = FieldValue.cross(gammaDirection);
278  gammaPolarization = gammaPolarization.unit();
279 
280  // create G4DynamicParticle object for the SR photon
281 
282  G4DynamicParticle* aGamma= new G4DynamicParticle ( theGamma,
283  gammaDirection,
284  energyOfSR );
285  aGamma->SetPolarization( gammaPolarization.x(),
286  gammaPolarization.y(),
287  gammaPolarization.z() );
288 
291 
292  // Update the incident particle
293 
294  G4double newKinEnergy = kineticEnergy - energyOfSR;
295 
296  if (newKinEnergy > 0.)
297  {
298  aParticleChange.ProposeEnergy( newKinEnergy );
299  }
300  else
301  {
303  }
304  }
305  }
306  return G4VDiscreteProcess::PostStepDoIt(trackData,stepData);
307 }
308 
310 //
311 //
312 
314 // direct generation
315 {
316  // from 0 to 0.7
317  static const G4double aa1=0 ,aa2=0.7;
318  static const G4int ncheb1=27;
319  static const G4double cheb1[] =
320  { 1.22371665676046468821,0.108956475422163837267,0.0383328524358594396134,0.00759138369340257753721,
321  0.00205712048644963340914,0.000497810783280019308661,0.000130743691810302187818,0.0000338168760220395409734,
322  8.97049680900520817728e-6,2.38685472794452241466e-6,6.41923109149104165049e-7,1.73549898982749277843e-7,
323  4.72145949240790029153e-8,1.29039866111999149636e-8,3.5422080787089834182e-9,9.7594757336403784905e-10,
324  2.6979510184976065731e-10,7.480422622550977077e-11,2.079598176402699913e-11,5.79533622220841193e-12,
325  1.61856011449276096e-12,4.529450993473807e-13,1.2698603951096606e-13,3.566117394511206e-14,1.00301587494091e-14,
326  2.82515346447219e-15,7.9680747949792e-16};
327  // from 0.7 to 0.9132260271183847
328  static const G4double aa3=0.9132260271183847;
329  static const G4int ncheb2=27;
330  static const G4double cheb2[] =
331  { 1.1139496701107756,0.3523967429328067,0.0713849171926623,0.01475818043595387,0.003381255637322462,
332  0.0008228057599452224,0.00020785506681254216,0.00005390169253706556,0.000014250571923902464,3.823880733161044e-6,
333  1.0381966089136036e-6,2.8457557457837253e-7,7.86223332179956e-8,2.1866609342508474e-8,6.116186259857143e-9,
334  1.7191233618437565e-9,4.852755117740807e-10,1.3749966961763457e-10,3.908961987062447e-11,1.1146253766895824e-11,
335  3.1868887323415814e-12,9.134319791300977e-13,2.6211077371181566e-13,7.588643377757906e-14,2.1528376972619e-14,
336  6.030906040404772e-15,1.9549163926819867e-15};
337  // Chebyshev with exp/log scale
338  // a = -Log[1 - SynFracInt[1]]; b = -Log[1 - SynFracInt[7]];
339  static const G4double aa4=2.4444485538746025480,aa5=9.3830728608909477079;
340  static const G4int ncheb3=28;
341  static const G4double cheb3[] =
342  { 1.2292683840435586977,0.160353449247864455879,-0.0353559911947559448721,0.00776901561223573936985,
343  -0.00165886451971685133259,0.000335719118906954279467,-0.0000617184951079161143187,9.23534039743246708256e-6,
344  -6.06747198795168022842e-7,-3.07934045961999778094e-7,1.98818772614682367781e-7,-8.13909971567720135413e-8,
345  2.84298174969641838618e-8,-9.12829766621316063548e-9,2.77713868004820551077e-9,-8.13032767247834023165e-10,
346  2.31128525568385247392e-10,-6.41796873254200220876e-11,1.74815310473323361543e-11,-4.68653536933392363045e-12,
347  1.24016595805520752748e-12,-3.24839432979935522159e-13,8.44601465226513952994e-14,-2.18647276044246803998e-14,
348  5.65407548745690689978e-15,-1.46553625917463067508e-15,3.82059606377570462276e-16,-1.00457896653436912508e-16};
349  static const G4double aa6=33.122936966163038145;
350  static const G4int ncheb4=27;
351  static const G4double cheb4[] =
352  {1.69342658227676741765,0.0742766400841232319225,-0.019337880608635717358,0.00516065527473364110491,
353  -0.00139342012990307729473,0.000378549864052022522193,-0.000103167085583785340215,0.0000281543441271412178337,
354  -7.68409742018258198651e-6,2.09543221890204537392e-6,-5.70493140367526282946e-7,1.54961164548564906446e-7,
355  -4.19665599629607704794e-8,1.13239680054166507038e-8,-3.04223563379021441863e-9,8.13073745977562957997e-10,
356  -2.15969415476814981374e-10,5.69472105972525594811e-11,-1.48844799572430829499e-11,3.84901514438304484973e-12,
357  -9.82222575944247161834e-13,2.46468329208292208183e-13,-6.04953826265982691612e-14,1.44055805710671611984e-14,
358  -3.28200813577388740722e-15,6.96566359173765367675e-16,-1.294122794852896275e-16};
359 
360  if(x<aa2) return x*x*x*Chebyshev(aa1,aa2,cheb1,ncheb1,x);
361  else if(x<aa3) return Chebyshev(aa2,aa3,cheb2,ncheb2,x);
362  else if(x<1-0.0000841363)
363  { G4double y=-G4Log(1-x);
364  return y*Chebyshev(aa4,aa5,cheb3,ncheb3,y);
365  }
366  else
367  { G4double y=-G4Log(1-x);
368  return y*Chebyshev(aa5,aa6,cheb4,ncheb4,y);
369  }
370 }
371 
372 G4double
374 {
375 
376  G4double Ecr=fEnergyConst*gamma*gamma*perpB;
377 
378  // static G4ThreadLocal G4bool FirstTime=true;
379  if(verboseLevel > 0 && FirstTime1)
380  { G4double Emean=8./(15.*std::sqrt(3.))*Ecr; // mean photon energy
381  G4double E_rms=std::sqrt(211./675.)*Ecr; // rms of photon energy distribution
382  G4int prec = G4cout.precision();
383  G4cout << "G4SynchrotronRadiation::GetRandomEnergySR :" << '\n'
384  << std::setprecision(4)
385  << " Ecr = " << G4BestUnit(Ecr,"Energy") << '\n'
386  << " Emean = " << G4BestUnit(Emean,"Energy") << '\n'
387  << " E_rms = " << G4BestUnit(E_rms,"Energy") << G4endl;
388  FirstTime1=false;
389  G4cout.precision(prec);
390  }
391 
392  G4double energySR=Ecr*InvSynFracInt(G4UniformRand());
393  return energySR;
394 }
395 
397 //
398 //
399 
400 void
402 {
403  if(0 < verboseLevel && &part==theElectron ) PrintInfoDefinition();
404 }
405 
407 //
408 //
409 
411 // not yet called, usually called from BuildPhysicsTable
412 {
413  G4String comments ="Incoherent Synchrotron Radiation\n";
414  G4cout << G4endl << GetProcessName() << ": " << comments
415  << " good description for long magnets at all energies"
416  << G4endl;
417 }
418 
G4double condition(const G4ErrorSymMatrix &m)
double getR() const
G4int verboseLevel
Definition: G4VProcess.hh:368
G4double GetKineticEnergy() const
CLHEP::Hep3Vector G4ThreeVector
G4double GetTotalEnergy() const
virtual void GetFieldValue(const double Point[4], double *fieldArr) const =0
double x() const
const G4DynamicParticle * GetDynamicParticle() const
G4double Chebyshev(G4double a, G4double b, const G4double c[], G4int n, G4double x)
const char * p
Definition: xmltok.h:285
const G4ThreeVector & GetPosition() const
G4ParticleDefinition * GetDefinition() const
tuple x
Definition: test.py:50
#define G4BestUnit(a, b)
#define G4_USE_G4BESTUNIT_FOR_VERBOSE 1
virtual void BuildPhysicsTable(const G4ParticleDefinition &)
virtual G4bool IsApplicable(const G4ParticleDefinition &)
G4double GetRandomEnergySR(G4double, G4double)
int G4int
Definition: G4Types.hh:78
double z() const
Double_t y
Definition: plot.C:279
#define G4UniformRand()
Definition: Randomize.hh:87
G4GLOB_DLL std::ostream G4cout
virtual G4ThreeVector & SampleDirection(const G4DynamicParticle *dp, G4double finalTotalEnergy, G4int Z, const G4Material *)=0
G4SynchrotronRadiation(const G4String &pName="SynRad", G4ProcessType type=fElectromagnetic)
G4double GetMass() const
bool G4bool
Definition: G4Types.hh:79
const G4ThreeVector & GetMomentumDirection() const
TString part[npart]
Definition: Style.C:32
void SetProcessSubType(G4int)
Definition: G4VProcess.hh:432
float electron_mass_c2
Definition: hepunit.py:274
virtual G4double GetMeanFreePath(const G4Track &track, G4double previousStepSize, G4ForceCondition *condition)
Definition: G4Step.hh:76
G4double GetGlobalTime() const
void SetPolarization(G4double polX, G4double polY, G4double polZ)
const G4String & GetProcessName() const
Definition: G4VProcess.hh:408
G4FieldManager * FindAndSetFieldManager(G4VPhysicalVolume *pCurrentPhysVol)
double theta() const
static G4TransportationManager * GetTransportationManager()
G4double G4Log(G4double x)
Definition: G4Log.hh:227
virtual void Initialize(const G4Track &)
void SetNumberOfSecondaries(G4int totSecondaries)
Hep3Vector unit() const
double y() const
void ProposeEnergy(G4double finalEnergy)
G4ParticleChange aParticleChange
Definition: G4VProcess.hh:289
G4VPhysicalVolume * GetVolume() const
void AddSecondary(G4Track *aSecondary)
#define G4endl
Definition: G4ios.hh:61
G4double InvSynFracInt(G4double x)
Hep3Vector cross(const Hep3Vector &) const
double G4double
Definition: G4Types.hh:76
const G4Field * GetDetectorField() const
G4ForceCondition
virtual G4VParticleChange * PostStepDoIt(const G4Track &track, const G4Step &Step)
G4double GetPDGCharge() const
G4PropagatorInField * GetPropagatorInField() const
double mag() const
#define DBL_MAX
Definition: templates.hh:83
void SetAngularGenerator(G4VEmAngularDistribution *p)
virtual G4VParticleChange * PostStepDoIt(const G4Track &, const G4Step &)
float c_light
Definition: hepunit.py:257
G4ThreeVector GetMomentum() const
G4ProcessType