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G4SeltzerBergerModel.cc
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26 // $Id$
27 //
28 // -------------------------------------------------------------------
29 //
30 // GEANT4 Class file
31 //
32 //
33 // File name: G4SeltzerBergerModel
34 //
35 // Author: Vladimir Ivanchenko use inheritance from Andreas Schaelicke
36 // base class implementing ultra relativistic bremsstrahlung
37 // model
38 //
39 // Creation date: 04.10.2011
40 //
41 // Modifications:
42 //
43 // -------------------------------------------------------------------
44 //
45 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
46 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
47 
48 #include "G4SeltzerBergerModel.hh"
49 #include "G4PhysicalConstants.hh"
50 #include "G4SystemOfUnits.hh"
51 #include "G4Electron.hh"
52 #include "G4Positron.hh"
53 #include "G4Gamma.hh"
54 #include "Randomize.hh"
55 #include "G4Material.hh"
56 #include "G4Element.hh"
57 #include "G4ElementVector.hh"
58 #include "G4ProductionCutsTable.hh"
59 #include "G4ParticleChangeForLoss.hh"
60 #include "G4LossTableManager.hh"
61 #include "G4ModifiedTsai.hh"
62 
63 #include "G4Physics2DVector.hh"
64 
65 #include "G4ios.hh"
66 #include <fstream>
67 #include <iomanip>
68 
69 
70 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
71 
72 using namespace std;
73 
74 G4Physics2DVector* G4SeltzerBergerModel::dataSB[101] = {0};
75 G4double G4SeltzerBergerModel::ylimit[101] = {0.0};
76 G4double G4SeltzerBergerModel::expnumlim = -12.;
77 
78 G4SeltzerBergerModel::G4SeltzerBergerModel(const G4ParticleDefinition* p,
79  const G4String& nam)
80  : G4eBremsstrahlungRelModel(p,nam),useBicubicInterpolation(false)
81 {
82  SetLowEnergyLimit(0.0);
83  SetLPMFlag(false);
84  nwarn = 0;
85 }
86 
87 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
88 
89 G4SeltzerBergerModel::~G4SeltzerBergerModel()
90 {
91  for(size_t i=0; i<101; ++i) {
92  if(dataSB[i]) {
93  delete dataSB[i];
94  dataSB[i] = 0;
95  }
96  }
97 }
98 
99 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
100 
101 void G4SeltzerBergerModel::Initialise(const G4ParticleDefinition* p,
102  const G4DataVector& cuts)
103 {
104  // check environment variable
105  // Build the complete string identifying the file with the data set
106  char* path = getenv("G4LEDATA");
107 
108  // Access to elements
109  const G4ElementTable* theElmTable = G4Element::GetElementTable();
110  size_t numOfElm = G4Element::GetNumberOfElements();
111  if(numOfElm > 0) {
112  for(size_t i=0; i<numOfElm; ++i) {
113  G4int Z = G4int(((*theElmTable)[i])->GetZ());
114  if(Z < 1) { Z = 1; }
115  else if(Z > 100) { Z = 100; }
116  //G4cout << "Z= " << Z << G4endl;
117  // Initialisation
118  if(!dataSB[Z]) { ReadData(Z, path); }
119  }
120  }
121 
122  G4eBremsstrahlungRelModel::Initialise(p, cuts);
123 }
124 
125 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
126 
127 void G4SeltzerBergerModel::ReadData(size_t Z, const char* path)
128 {
129  // G4cout << "ReadData Z= " << Z << G4endl;
130  // G4cout << "Status for Z= " << dataSB[Z] << G4endl;
131  //if(path) { G4cout << path << G4endl; }
132  if(dataSB[Z]) { return; }
133  const char* datadir = path;
134 
135  if(!datadir) {
136  datadir = getenv("G4LEDATA");
137  if(!datadir) {
138  G4Exception("G4SeltzerBergerModel::ReadData()","em0006",FatalException,
139  "Environment variable G4LEDATA not defined");
140  return;
141  }
142  }
143  std::ostringstream ost;
144  ost << datadir << "/brem_SB/br" << Z;
145  std::ifstream fin(ost.str().c_str());
146  if( !fin.is_open()) {
147  G4ExceptionDescription ed;
148  ed << "Bremsstrahlung data file <" << ost.str().c_str()
149  << "> is not opened!" << G4endl;
150  G4Exception("G4SeltzerBergerModel::ReadData()","em0003",FatalException,
151  ed,"G4LEDATA version should be G4EMLOW6.23 or later.");
152  return;
153  }
154  //G4cout << "G4SeltzerBergerModel read from <" << ost.str().c_str()
155  // << ">" << G4endl;
156  G4Physics2DVector* v = new G4Physics2DVector();
157  const G4double emaxlog = 4*log(10.);
158  if(v->Retrieve(fin)) {
159  if(useBicubicInterpolation) { v->SetBicubicInterpolation(true); }
160  dataSB[Z] = v;
161  ylimit[Z] = v->Value(0.97, emaxlog);
162  } else {
163  G4ExceptionDescription ed;
164  ed << "Bremsstrahlung data file <" << ost.str().c_str()
165  << "> is not retrieved!" << G4endl;
166  G4Exception("G4SeltzerBergerModel::ReadData()","em0005",FatalException,
167  ed,"G4LEDATA version should be G4EMLOW6.23 or later.");
168  delete v;
169  }
170  // G4cout << dataSB[Z] << G4endl;
171 }
172 
173 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
174 
175 G4double G4SeltzerBergerModel::ComputeDXSectionPerAtom(G4double gammaEnergy)
176 {
177 
178  if(gammaEnergy < 0.0 || kinEnergy <= 0.0) { return 0.0; }
179  G4double x = gammaEnergy/kinEnergy;
180  G4double y = log(kinEnergy/MeV);
181  G4int Z = G4int(currentZ);
182  //G4cout << "G4SeltzerBergerModel::ComputeDXSectionPerAtom Z= " << Z
183  // << " x= " << x << " y= " << y << " " << dataSB[Z] << G4endl;
184  if(!dataSB[Z]) { ReadData(Z); }
185  G4double invb2 = totalEnergy*totalEnergy/(kinEnergy*(kinEnergy + 2*particleMass));
186  G4double cross = dataSB[Z]->Value(x,y)*invb2*millibarn/bremFactor;
187 
188  if(!isElectron) {
189  G4double invbeta1 = sqrt(invb2);
190  G4double e2 = kinEnergy - gammaEnergy;
191  if(e2 > 0.0) {
192  G4double invbeta2 = (e2 + particleMass)/sqrt(e2*(e2 + 2*particleMass));
193  G4double xxx = twopi*fine_structure_const*currentZ*(invbeta1 - invbeta2);
194  if(xxx < expnumlim) { cross = 0.0; }
195  else { cross *= exp(xxx); }
196  } else {
197  cross = 0.0;
198  }
199  }
200 
201  return cross;
202 }
203 
204 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
205 
206 void
207 G4SeltzerBergerModel::SampleSecondaries(std::vector<G4DynamicParticle*>* vdp,
208  const G4MaterialCutsCouple* couple,
209  const G4DynamicParticle* dp,
210  G4double cutEnergy,
211  G4double maxEnergy)
212 {
213  G4double kineticEnergy = dp->GetKineticEnergy();
214  G4double cut = std::min(cutEnergy, kineticEnergy);
215  G4double emax = std::min(maxEnergy, kineticEnergy);
216  if(cut >= emax) { return; }
217 
218  SetupForMaterial(particle, couple->GetMaterial(), kineticEnergy);
219 
220  const G4Element* elm =
221  SelectRandomAtom(couple,particle,kineticEnergy,cut,emax);
222  SetCurrentElement(elm->GetZ());
223  G4int Z = G4int(currentZ);
224 
225  totalEnergy = kineticEnergy + particleMass;
226  densityCorr = densityFactor*totalEnergy*totalEnergy;
227  G4double totMomentum = sqrt(kineticEnergy*(totalEnergy + electron_mass_c2));
228  /*
229  G4cout << "G4SeltzerBergerModel::SampleSecondaries E(MeV)= "
230  << kineticEnergy/MeV
231  << " Z= " << Z << " cut(MeV)= " << cut/MeV
232  << " emax(MeV)= " << emax/MeV << " corr= " << densityCorr << G4endl;
233  */
234  G4double xmin = log(cut*cut + densityCorr);
235  G4double xmax = log(emax*emax + densityCorr);
236  G4double y = log(kineticEnergy/MeV);
237 
238  G4double gammaEnergy, v;
239 
240  // majoranta
241  G4double x0 = cut/kineticEnergy;
242  G4double vmax = dataSB[Z]->Value(x0, y)*1.02;
243  // G4double invbeta1 = 0;
244 
245  const G4double epeaklimit= 300*MeV;
246  const G4double elowlimit = 10*keV;
247 
248  // majoranta corrected for e-
249  if(isElectron && x0 < 0.97 &&
250  ((kineticEnergy > epeaklimit) || (kineticEnergy < elowlimit))) {
251  G4double ylim = std::min(ylimit[Z],1.1*dataSB[Z]->Value(0.97, y));
252  if(ylim > vmax) { vmax = ylim; }
253  }
254  if(x0 < 0.05) { vmax *= 1.2; }
255 
256  //G4cout<<"y= "<<y<<" xmin= "<<xmin<<" xmax= "<<xmax<<" vmax= "<<vmax<<G4endl;
257  // G4int ncount = 0;
258  do {
259  //++ncount;
260  G4double x = exp(xmin + G4UniformRand()*(xmax - xmin)) - densityCorr;
261  if(x < 0.0) { x = 0.0; }
262  gammaEnergy = sqrt(x);
263  G4double x1 = gammaEnergy/kineticEnergy;
264  v = dataSB[Z]->Value(x1, y);
265 
266  // correction for positrons
267  if(!isElectron) {
268  G4double e1 = kineticEnergy - cut;
269  G4double invbeta1 = (e1 + particleMass)/sqrt(e1*(e1 + 2*particleMass));
270  G4double e2 = kineticEnergy - gammaEnergy;
271  G4double invbeta2 = (e2 + particleMass)/sqrt(e2*(e2 + 2*particleMass));
272  G4double xxx = twopi*fine_structure_const*currentZ*(invbeta1 - invbeta2);
273 
274  if(xxx < expnumlim) { v = 0.0; }
275  else { v *= exp(xxx); }
276  }
277 
278  if (v > 1.05*vmax && nwarn < 20) {
279  ++nwarn;
280  G4cout << "### G4SeltzerBergerModel Warning: Majoranta exceeded! "
281  << v << " > " << vmax << " by " << v/vmax
282  << " Egamma(MeV)= " << gammaEnergy
283  << " Ee(MeV)= " << kineticEnergy
284  << " Z= " << Z << " " << particle->GetParticleName()
285  //<< " ncount= " << ncount
286  << G4endl;
287 
288  if ( 20 == nwarn ) {
289  G4cout << "### G4SeltzerBergerModel Warnings will not be printed anymore"
290  << G4endl;
291  }
292  }
293  } while (v < vmax*G4UniformRand());
294 
295  //
296  // angles of the emitted gamma. ( Z - axis along the parent particle)
297  // use general interface
298  //
299 
300  G4ThreeVector gammaDirection =
301  GetAngularDistribution()->SampleDirection(dp, totalEnergy-gammaEnergy,
302  Z, couple->GetMaterial());
303 
304  // create G4DynamicParticle object for the Gamma
305  G4DynamicParticle* gamma =
306  new G4DynamicParticle(theGamma,gammaDirection,gammaEnergy);
307  vdp->push_back(gamma);
308 
309  G4ThreeVector direction = (totMomentum*dp->GetMomentumDirection()
310  - gammaEnergy*gammaDirection).unit();
311 
312  /*
313  G4cout << "### G4SBModel: v= "
314  << " Eg(MeV)= " << gammaEnergy
315  << " Ee(MeV)= " << kineticEnergy
316  << " DirE " << direction << " DirG " << gammaDirection
317  << G4endl;
318  */
319  // energy of primary
320  G4double finalE = kineticEnergy - gammaEnergy;
321 
322  // stop tracking and create new secondary instead of primary
323  if(gammaEnergy > SecondaryThreshold()) {
324  fParticleChange->ProposeTrackStatus(fStopAndKill);
325  fParticleChange->SetProposedKineticEnergy(0.0);
326  G4DynamicParticle* el =
327  new G4DynamicParticle(const_cast<G4ParticleDefinition*>(particle),
328  direction, finalE);
329  vdp->push_back(el);
330 
331  // continue tracking
332  } else {
333  fParticleChange->SetProposedMomentumDirection(direction);
334  fParticleChange->SetProposedKineticEnergy(finalE);
335  }
336 }
337 
338 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
339 
340 
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