QwGeant4
QweakSimUrbanMscModel.cc
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29 // -------------------------------------------------------------------
30 //
31 // GEANT4 Class file
32 //
33 //
34 // File name: G4UrbanMscModel96
35 //
36 // Author: Laszlo Urban
37 //
38 // Creation date: 26.09.2012
39 //
40 // Created from G4UrbanMscModel95
41 //
42 // New parametrization for theta0
43 // Correction for very small step length
44 //
45 // Class Description:
46 //
47 // Implementation of the model of multiple scattering based on
48 // H.W.Lewis Phys Rev 78 (1950) 526 and others
49 
50 // -------------------------------------------------------------------
51 // In its present form the model can be used for simulation
52 // of the e-/e+ multiple scattering
53 //
54 
55 
56 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
57 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
58 
59 #include "processes/electromagnetic/standard/QweakSimUrbanMscModel.hh"
60 
61 #include "G4PhysicalConstants.hh"
62 #include "G4SystemOfUnits.hh"
63 #include "Randomize.hh"
64 #include "G4Electron.hh"
65 #include "G4LossTableManager.hh"
66 #include "G4ParticleChangeForMSC.hh"
67 
68 #include "G4Poisson.hh"
69 #include "globals.hh"
70 #include "G4Pow.hh"
71 #include "math.h"
72 
73 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
74 
75 using namespace std;
76 
77 QweakSimUrbanMscModel::QweakSimUrbanMscModel(const G4String& nam)
78  : G4VMscModel(nam)
79 {
80  masslimite = 0.6*MeV;
81  lambdalimit = 1.*mm;
82  fr = 0.02;
83  taubig = 8.0;
84  tausmall = 1.e-16;
85  taulim = 1.e-6;
86  currentTau = taulim;
87  tlimitminfix = 1.e-6*mm;
88  stepmin = tlimitminfix;
89  smallstep = 1.e10;
90  currentRange = 0. ;
91  rangeinit = 0.;
92  tlimit = 1.e10*mm;
93  tlimitmin = 10.*tlimitminfix;
94  tgeom = 1.e50*mm;
95  geombig = 1.e50*mm;
96  geommin = 1.e-3*mm;
97  geomlimit = geombig;
98  presafety = 0.*mm;
99  //facsafety = 0.50 ;
100 
101  y = 0.;
102 
103  Zold = 0.;
104  Zeff = 1.;
105  Z2 = 1.;
106  Z23 = 1.;
107  lnZ = 0.;
108  coeffth1 = 0.;
109  coeffth2 = 0.;
110  coeffc1 = 0.;
111  coeffc2 = 0.;
112  coeffc3 = 0.;
113  coeffc4 = 0.;
114 
115  theta0max = pi/6.;
116  rellossmax = 0.50;
117  third = 1./3.;
118  particle = 0;
119  theManager = G4LossTableManager::Instance();
120  firstStep = true;
121  inside = false;
122  insideskin = false;
123 
124  skindepth = skin*stepmin;
125 
126  mass = proton_mass_c2;
127  charge = ChargeSquare = 1.0;
128  currentKinEnergy = currentRadLength = lambda0 = lambdaeff = tPathLength
129  = zPathLength = par1 = par2 = par3 = 0;
130 
131  currentMaterialIndex = -1;
132  fParticleChange = 0;
133  couple = 0;
134  SetSampleZ(false);
135 }
136 
137 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
138 
139 QweakSimUrbanMscModel::~QweakSimUrbanMscModel()
140 {}
141 
142 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
143 
144 void QweakSimUrbanMscModel::Initialise(const G4ParticleDefinition* p,
145  const G4DataVector&)
146 {
147  skindepth = skin*stepmin;
148  // trackID = -1;
149 
150  // set values of some data members
151  SetParticle(p);
152  /*
153  if(p->GetPDGMass() > MeV) {
154  G4cout << "### WARNING: QweakSimUrbanMscModel model is used for "
155  << p->GetParticleName() << " !!! " << G4endl;
156  G4cout << "### This model should be used only for e+-"
157  << G4endl;
158  }
159  */
160  fParticleChange = GetParticleChangeForMSC(p);
161 
162  //samplez = true;
163  //G4cout << "### QweakSimUrbanMscModel::Initialise done!" << G4endl;
164 }
165 
166 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
167 
168 G4double QweakSimUrbanMscModel::ComputeCrossSectionPerAtom(
169  const G4ParticleDefinition* part,
170  G4double KineticEnergy,
171  G4double AtomicNumber,G4double,
172  G4double, G4double)
173 {
174  static const G4double sigmafactor =
175  twopi*classic_electr_radius*classic_electr_radius;
176  static const G4double epsfactor = 2.*electron_mass_c2*electron_mass_c2*
177  Bohr_radius*Bohr_radius/(hbarc*hbarc);
178  static const G4double epsmin = 1.e-4 , epsmax = 1.e10;
179 
180  static const G4double Zdat[15] = { 4., 6., 13., 20., 26., 29., 32., 38., 47.,
181  50., 56., 64., 74., 79., 82. };
182 
183  static const G4double Tdat[22] = { 100*eV, 200*eV, 400*eV, 700*eV,
184  1*keV, 2*keV, 4*keV, 7*keV,
185  10*keV, 20*keV, 40*keV, 70*keV,
186  100*keV, 200*keV, 400*keV, 700*keV,
187  1*MeV, 2*MeV, 4*MeV, 7*MeV,
188  10*MeV, 20*MeV};
189 
190  // corr. factors for e-/e+ lambda for T <= Tlim
191  static const G4double celectron[15][22] =
192  {{1.125,1.072,1.051,1.047,1.047,1.050,1.052,1.054,
193  1.054,1.057,1.062,1.069,1.075,1.090,1.105,1.111,
194  1.112,1.108,1.100,1.093,1.089,1.087 },
195  {1.408,1.246,1.143,1.096,1.077,1.059,1.053,1.051,
196  1.052,1.053,1.058,1.065,1.072,1.087,1.101,1.108,
197  1.109,1.105,1.097,1.090,1.086,1.082 },
198  {2.833,2.268,1.861,1.612,1.486,1.309,1.204,1.156,
199  1.136,1.114,1.106,1.106,1.109,1.119,1.129,1.132,
200  1.131,1.124,1.113,1.104,1.099,1.098 },
201  {3.879,3.016,2.380,2.007,1.818,1.535,1.340,1.236,
202  1.190,1.133,1.107,1.099,1.098,1.103,1.110,1.113,
203  1.112,1.105,1.096,1.089,1.085,1.098 },
204  {6.937,4.330,2.886,2.256,1.987,1.628,1.395,1.265,
205  1.203,1.122,1.080,1.065,1.061,1.063,1.070,1.073,
206  1.073,1.070,1.064,1.059,1.056,1.056 },
207  {9.616,5.708,3.424,2.551,2.204,1.762,1.485,1.330,
208  1.256,1.155,1.099,1.077,1.070,1.068,1.072,1.074,
209  1.074,1.070,1.063,1.059,1.056,1.052 },
210  {11.72,6.364,3.811,2.806,2.401,1.884,1.564,1.386,
211  1.300,1.180,1.112,1.082,1.073,1.066,1.068,1.069,
212  1.068,1.064,1.059,1.054,1.051,1.050 },
213  {18.08,8.601,4.569,3.183,2.662,2.025,1.646,1.439,
214  1.339,1.195,1.108,1.068,1.053,1.040,1.039,1.039,
215  1.039,1.037,1.034,1.031,1.030,1.036 },
216  {18.22,10.48,5.333,3.713,3.115,2.367,1.898,1.631,
217  1.498,1.301,1.171,1.105,1.077,1.048,1.036,1.033,
218  1.031,1.028,1.024,1.022,1.021,1.024 },
219  {14.14,10.65,5.710,3.929,3.266,2.453,1.951,1.669,
220  1.528,1.319,1.178,1.106,1.075,1.040,1.027,1.022,
221  1.020,1.017,1.015,1.013,1.013,1.020 },
222  {14.11,11.73,6.312,4.240,3.478,2.566,2.022,1.720,
223  1.569,1.342,1.186,1.102,1.065,1.022,1.003,0.997,
224  0.995,0.993,0.993,0.993,0.993,1.011 },
225  {22.76,20.01,8.835,5.287,4.144,2.901,2.219,1.855,
226  1.677,1.410,1.224,1.121,1.073,1.014,0.986,0.976,
227  0.974,0.972,0.973,0.974,0.975,0.987 },
228  {50.77,40.85,14.13,7.184,5.284,3.435,2.520,2.059,
229  1.837,1.512,1.283,1.153,1.091,1.010,0.969,0.954,
230  0.950,0.947,0.949,0.952,0.954,0.963 },
231  {65.87,59.06,15.87,7.570,5.567,3.650,2.682,2.182,
232  1.939,1.579,1.325,1.178,1.108,1.014,0.965,0.947,
233  0.941,0.938,0.940,0.944,0.946,0.954 },
234  {55.60,47.34,15.92,7.810,5.755,3.767,2.760,2.239,
235  1.985,1.609,1.343,1.188,1.113,1.013,0.960,0.939,
236  0.933,0.930,0.933,0.936,0.939,0.949 }};
237 
238  static const G4double cpositron[15][22] = {
239  {2.589,2.044,1.658,1.446,1.347,1.217,1.144,1.110,
240  1.097,1.083,1.080,1.086,1.092,1.108,1.123,1.131,
241  1.131,1.126,1.117,1.108,1.103,1.100 },
242  {3.904,2.794,2.079,1.710,1.543,1.325,1.202,1.145,
243  1.122,1.096,1.089,1.092,1.098,1.114,1.130,1.137,
244  1.138,1.132,1.122,1.113,1.108,1.102 },
245  {7.970,6.080,4.442,3.398,2.872,2.127,1.672,1.451,
246  1.357,1.246,1.194,1.179,1.178,1.188,1.201,1.205,
247  1.203,1.190,1.173,1.159,1.151,1.145 },
248  {9.714,7.607,5.747,4.493,3.815,2.777,2.079,1.715,
249  1.553,1.353,1.253,1.219,1.211,1.214,1.225,1.228,
250  1.225,1.210,1.191,1.175,1.166,1.174 },
251  {17.97,12.95,8.628,6.065,4.849,3.222,2.275,1.820,
252  1.624,1.382,1.259,1.214,1.202,1.202,1.214,1.219,
253  1.217,1.203,1.184,1.169,1.160,1.151 },
254  {24.83,17.06,10.84,7.355,5.767,3.707,2.546,1.996,
255  1.759,1.465,1.311,1.252,1.234,1.228,1.238,1.241,
256  1.237,1.222,1.201,1.184,1.174,1.159 },
257  {23.26,17.15,11.52,8.049,6.375,4.114,2.792,2.155,
258  1.880,1.535,1.353,1.281,1.258,1.247,1.254,1.256,
259  1.252,1.234,1.212,1.194,1.183,1.170 },
260  {22.33,18.01,12.86,9.212,7.336,4.702,3.117,2.348,
261  2.015,1.602,1.385,1.297,1.268,1.251,1.256,1.258,
262  1.254,1.237,1.214,1.195,1.185,1.179 },
263  {33.91,24.13,15.71,10.80,8.507,5.467,3.692,2.808,
264  2.407,1.873,1.564,1.425,1.374,1.330,1.324,1.320,
265  1.312,1.288,1.258,1.235,1.221,1.205 },
266  {32.14,24.11,16.30,11.40,9.015,5.782,3.868,2.917,
267  2.490,1.925,1.596,1.447,1.391,1.342,1.332,1.327,
268  1.320,1.294,1.264,1.240,1.226,1.214 },
269  {29.51,24.07,17.19,12.28,9.766,6.238,4.112,3.066,
270  2.602,1.995,1.641,1.477,1.414,1.356,1.342,1.336,
271  1.328,1.302,1.270,1.245,1.231,1.233 },
272  {38.19,30.85,21.76,15.35,12.07,7.521,4.812,3.498,
273  2.926,2.188,1.763,1.563,1.484,1.405,1.382,1.371,
274  1.361,1.330,1.294,1.267,1.251,1.239 },
275  {49.71,39.80,27.96,19.63,15.36,9.407,5.863,4.155,
276  3.417,2.478,1.944,1.692,1.589,1.480,1.441,1.423,
277  1.409,1.372,1.330,1.298,1.280,1.258 },
278  {59.25,45.08,30.36,20.83,16.15,9.834,6.166,4.407,
279  3.641,2.648,2.064,1.779,1.661,1.531,1.482,1.459,
280  1.442,1.400,1.354,1.319,1.299,1.272 },
281  {56.38,44.29,30.50,21.18,16.51,10.11,6.354,4.542,
282  3.752,2.724,2.116,1.817,1.692,1.554,1.499,1.474,
283  1.456,1.412,1.364,1.328,1.307,1.282 }};
284 
285  //data/corrections for T > Tlim
286  static const G4double Tlim = 10.*MeV;
287  static const G4double beta2lim = Tlim*(Tlim+2.*electron_mass_c2)/
288  ((Tlim+electron_mass_c2)*(Tlim+electron_mass_c2));
289  static const G4double bg2lim = Tlim*(Tlim+2.*electron_mass_c2)/
290  (electron_mass_c2*electron_mass_c2);
291 
292  static const G4double sig0[15] = {
293  0.2672*barn, 0.5922*barn, 2.653*barn, 6.235*barn,
294  11.69*barn , 13.24*barn , 16.12*barn, 23.00*barn ,
295  35.13*barn , 39.95*barn , 50.85*barn, 67.19*barn ,
296  91.15*barn , 104.4*barn , 113.1*barn};
297 
298  static const G4double hecorr[15] = {
299  120.70, 117.50, 105.00, 92.92, 79.23, 74.510, 68.29,
300  57.39, 41.97, 36.14, 24.53, 10.21, -7.855, -16.84,
301  -22.30};
302 
303  G4double sigma;
304  SetParticle(part);
305 
306  Z23 = G4Pow::GetInstance()->Z23(G4lrint(AtomicNumber));
307 
308  // correction if particle .ne. e-/e+
309  // compute equivalent kinetic energy
310  // lambda depends on p*beta ....
311 
312  G4double eKineticEnergy = KineticEnergy;
313 
314  if(mass > electron_mass_c2)
315  {
316  G4double TAU = KineticEnergy/mass ;
317  G4double c = mass*TAU*(TAU+2.)/(electron_mass_c2*(TAU+1.)) ;
318  G4double w = c-2. ;
319  G4double tau = 0.5*(w+sqrt(w*w+4.*c)) ;
320  eKineticEnergy = electron_mass_c2*tau ;
321  }
322 
323  G4double eTotalEnergy = eKineticEnergy + electron_mass_c2 ;
324  G4double beta2 = eKineticEnergy*(eTotalEnergy+electron_mass_c2)
325  /(eTotalEnergy*eTotalEnergy);
326  G4double bg2 = eKineticEnergy*(eTotalEnergy+electron_mass_c2)
327  /(electron_mass_c2*electron_mass_c2);
328 
329  G4double eps = epsfactor*bg2/Z23;
330 
331  if (eps<epsmin) sigma = 2.*eps*eps;
332  else if(eps<epsmax) sigma = log(1.+2.*eps)-2.*eps/(1.+2.*eps);
333  else sigma = log(2.*eps)-1.+1./eps;
334 
335  sigma *= ChargeSquare*AtomicNumber*AtomicNumber/(beta2*bg2);
336 
337  // interpolate in AtomicNumber and beta2
338  G4double c1,c2,cc1,cc2,corr;
339 
340  // get bin number in Z
341  G4int iZ = 14;
342  while ((iZ>=0)&&(Zdat[iZ]>=AtomicNumber)) iZ -= 1;
343  if (iZ==14) iZ = 13;
344  if (iZ==-1) iZ = 0 ;
345 
346  G4double ZZ1 = Zdat[iZ];
347  G4double ZZ2 = Zdat[iZ+1];
348  G4double ratZ = (AtomicNumber-ZZ1)*(AtomicNumber+ZZ1)/
349  ((ZZ2-ZZ1)*(ZZ2+ZZ1));
350 
351  if(eKineticEnergy <= Tlim)
352  {
353  // get bin number in T (beta2)
354  G4int iT = 21;
355  while ((iT>=0)&&(Tdat[iT]>=eKineticEnergy)) iT -= 1;
356  if(iT==21) iT = 20;
357  if(iT==-1) iT = 0 ;
358 
359  // calculate betasquare values
360  G4double T = Tdat[iT], E = T + electron_mass_c2;
361  G4double b2small = T*(E+electron_mass_c2)/(E*E);
362 
363  T = Tdat[iT+1]; E = T + electron_mass_c2;
364  G4double b2big = T*(E+electron_mass_c2)/(E*E);
365  G4double ratb2 = (beta2-b2small)/(b2big-b2small);
366 
367  if (charge < 0.)
368  {
369  c1 = celectron[iZ][iT];
370  c2 = celectron[iZ+1][iT];
371  cc1 = c1+ratZ*(c2-c1);
372 
373  c1 = celectron[iZ][iT+1];
374  c2 = celectron[iZ+1][iT+1];
375  cc2 = c1+ratZ*(c2-c1);
376 
377  corr = cc1+ratb2*(cc2-cc1);
378 
379  sigma *= sigmafactor/corr;
380  }
381  else
382  {
383  c1 = cpositron[iZ][iT];
384  c2 = cpositron[iZ+1][iT];
385  cc1 = c1+ratZ*(c2-c1);
386 
387  c1 = cpositron[iZ][iT+1];
388  c2 = cpositron[iZ+1][iT+1];
389  cc2 = c1+ratZ*(c2-c1);
390 
391  corr = cc1+ratb2*(cc2-cc1);
392 
393  sigma *= sigmafactor/corr;
394  }
395  }
396  else
397  {
398  c1 = bg2lim*sig0[iZ]*(1.+hecorr[iZ]*(beta2-beta2lim))/bg2;
399  c2 = bg2lim*sig0[iZ+1]*(1.+hecorr[iZ+1]*(beta2-beta2lim))/bg2;
400  if((AtomicNumber >= ZZ1) && (AtomicNumber <= ZZ2))
401  sigma = c1+ratZ*(c2-c1) ;
402  else if(AtomicNumber < ZZ1)
403  sigma = AtomicNumber*AtomicNumber*c1/(ZZ1*ZZ1);
404  else if(AtomicNumber > ZZ2)
405  sigma = AtomicNumber*AtomicNumber*c2/(ZZ2*ZZ2);
406  }
407  return sigma;
408 
409 }
410 
411 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
412 
413 void QweakSimUrbanMscModel::StartTracking(G4Track* track)
414 {
415  SetParticle(track->GetDynamicParticle()->GetDefinition());
416  firstStep = true;
417  inside = false;
418  insideskin = false;
419  tlimit = geombig;
420  stepmin = tlimitminfix ;
421  tlimitmin = 10.*stepmin ;
422 }
423 
424 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
425 
426 G4double QweakSimUrbanMscModel::ComputeTruePathLengthLimit(
427  const G4Track& track,
428  G4double& currentMinimalStep)
429 {
430  tPathLength = currentMinimalStep;
431  const G4DynamicParticle* dp = track.GetDynamicParticle();
432 
433  //FIXME
434  ePolarized=false;
435  debugPrint=false;
436  if(strcmp(track.GetParticleDefinition()->GetParticleName().data() , "e-") == 0)
437  if(strcmp(track.GetMaterial()->GetName(),"PBA") == 0){
438  if(track.GetPolarization().getR() >= 0.1) debugPrint=true;
439  if(sqrt(pow(track.GetPolarization().getX(),2)+pow(track.GetPolarization().getY(),2))>0.01){
440  ePolarized=true;
441  polarization=track.GetPolarization();
442  eEnergy=track.GetTotalEnergy();
443  }
444  }
445  debugPrint=false;
446  //FIXME
447 
448  G4StepPoint* sp = track.GetStep()->GetPreStepPoint();
449  G4StepStatus stepStatus = sp->GetStepStatus();
450  couple = track.GetMaterialCutsCouple();
451  SetCurrentCouple(couple);
452  currentMaterialIndex = couple->GetIndex();
453  currentKinEnergy = dp->GetKineticEnergy();
454  currentRange = GetRange(particle,currentKinEnergy,couple);
455  lambda0 = GetTransportMeanFreePath(particle,currentKinEnergy);
456  if(tPathLength > currentRange) { tPathLength = currentRange; }
457 
458  // stop here if small range particle
459  if(inside || tPathLength < tlimitminfix) {
460  return ConvertTrueToGeom(tPathLength, currentMinimalStep);
461  }
462 
463  presafety = sp->GetSafety();
464  /*
465  G4cout << "G4Urban96::StepLimit tPathLength= "
466  <<tPathLength<<" safety= " << presafety
467  << " range= " <<currentRange<< " lambda= "<<lambda0
468  << " Alg: " << steppingAlgorithm <<G4endl;
469  */
470  // far from geometry boundary
471  if(currentRange < presafety)
472  {
473  inside = true;
474  return ConvertTrueToGeom(tPathLength, currentMinimalStep);
475  }
476 
477  // standard version
478  //
479  if (steppingAlgorithm == fUseDistanceToBoundary)
480  {
481  //compute geomlimit and presafety
482  geomlimit = ComputeGeomLimit(track, presafety, currentRange);
483 
484  // is it far from boundary ?
485  if(currentRange < presafety)
486  {
487  inside = true;
488  return ConvertTrueToGeom(tPathLength, currentMinimalStep);
489  }
490 
491  smallstep += 1.;
492  insideskin = false;
493 
494  if(firstStep || (stepStatus == fGeomBoundary))
495  {
496  rangeinit = currentRange;
497  if(firstStep) smallstep = 1.e10;
498  else smallstep = 1.;
499 
500  //define stepmin here (it depends on lambda!)
501  //rough estimation of lambda_elastic/lambda_transport
502  G4double rat = currentKinEnergy/MeV ;
503  rat = 1.e-3/(rat*(10.+rat)) ;
504  //stepmin ~ lambda_elastic
505  stepmin = rat*lambda0;
506  skindepth = skin*stepmin;
507  //define tlimitmin
508  tlimitmin = 10.*stepmin;
509  if(tlimitmin < tlimitminfix) tlimitmin = tlimitminfix;
510  //G4cout << "rangeinit= " << rangeinit << " stepmin= " << stepmin
511  // << " tlimitmin= " << tlimitmin << " geomlimit= " << geomlimit <<G4endl;
512  // constraint from the geometry
513  if((geomlimit < geombig) && (geomlimit > geommin))
514  {
515  // geomlimit is a geometrical step length
516  // transform it to true path length (estimation)
517  if((1.-geomlimit/lambda0) > 0.)
518  geomlimit = -lambda0*log(1.-geomlimit/lambda0)+tlimitmin ;
519 
520  if(stepStatus == fGeomBoundary)
521  tgeom = geomlimit/facgeom;
522  else
523  tgeom = 2.*geomlimit/facgeom;
524  }
525  else
526  tgeom = geombig;
527  }
528 
529 
530  //step limit
531  tlimit = facrange*rangeinit;
532 
533  //lower limit for tlimit
534  if(tlimit < tlimitmin) tlimit = tlimitmin;
535 
536  if(tlimit > tgeom) tlimit = tgeom;
537 
538  //G4cout << "tgeom= " << tgeom << " geomlimit= " << geomlimit
539  // << " tlimit= " << tlimit << " presafety= " << presafety << G4endl;
540 
541  // shortcut
542  if((tPathLength < tlimit) && (tPathLength < presafety) &&
543  (smallstep > skin) && (tPathLength < geomlimit-0.999*skindepth))
544  return ConvertTrueToGeom(tPathLength, currentMinimalStep);
545 
546  // step reduction near to boundary
547  if(smallstep <= skin)
548  {
549  tlimit = stepmin;
550  insideskin = true;
551  }
552  else if(geomlimit < geombig)
553  {
554  if(geomlimit > skindepth)
555  {
556  if(tlimit > geomlimit-0.999*skindepth)
557  tlimit = geomlimit-0.999*skindepth;
558  }
559  else
560  {
561  insideskin = true;
562  if(tlimit > stepmin) tlimit = stepmin;
563  }
564  }
565 
566  if(tlimit < stepmin) tlimit = stepmin;
567 
568  // randomize 1st step or 1st 'normal' step in volume
569  if(firstStep || ((smallstep == skin+1) && !insideskin))
570  {
571  G4double temptlimit = tlimit;
572  if(temptlimit > tlimitmin)
573  {
574  do {
575  temptlimit = G4RandGauss::shoot(tlimit,0.3*tlimit);
576  } while ((temptlimit < tlimitmin) ||
577  (temptlimit > 2.*tlimit-tlimitmin));
578  }
579  else
580  temptlimit = tlimitmin;
581  if(tPathLength > temptlimit) tPathLength = temptlimit;
582  }
583  else
584  {
585  if(tPathLength > tlimit) tPathLength = tlimit ;
586  }
587 
588  }
589  // for 'normal' simulation with or without magnetic field
590  // there no small step/single scattering at boundaries
591  else if(steppingAlgorithm == fUseSafety)
592  {
593  // compute presafety again if presafety <= 0 and no boundary
594  // i.e. when it is needed for optimization purposes
595  if((stepStatus != fGeomBoundary) && (presafety < tlimitminfix))
596  presafety = ComputeSafety(sp->GetPosition(),tPathLength);
597  /*
598  G4cout << "presafety= " << presafety
599  << " firstStep= " << firstStep
600  << " stepStatus= " << stepStatus
601  << G4endl;
602  */
603  // is far from boundary
604  if(currentRange < presafety)
605  {
606  inside = true;
607  return ConvertTrueToGeom(tPathLength, currentMinimalStep);
608  }
609 
610  if(firstStep || stepStatus == fGeomBoundary)
611  {
612  rangeinit = currentRange;
613  fr = facrange;
614  // 9.1 like stepping for e+/e- only (not for muons,hadrons)
615  if(mass < masslimite)
616  {
617  if(lambda0 > currentRange)
618  rangeinit = lambda0;
619  if(lambda0 > lambdalimit)
620  fr *= 0.75+0.25*lambda0/lambdalimit;
621  }
622 
623  //lower limit for tlimit
624  G4double rat = currentKinEnergy/MeV ;
625  rat = 1.e-3/(rat*(10.+rat)) ;
626  stepmin = lambda0*rat;
627  tlimitmin = 10.*stepmin;
628  if(tlimitmin < tlimitminfix) tlimitmin = tlimitminfix;
629  }
630  //step limit
631  tlimit = fr*rangeinit;
632 
633  if(tlimit < facsafety*presafety)
634  tlimit = facsafety*presafety;
635 
636  //lower limit for tlimit
637  if(tlimit < tlimitmin) tlimit = tlimitmin;
638 
639  if(firstStep || stepStatus == fGeomBoundary)
640  {
641  G4double temptlimit = tlimit;
642  if(temptlimit > tlimitmin)
643  {
644  do {
645  temptlimit = G4RandGauss::shoot(tlimit,0.3*tlimit);
646  } while ((temptlimit < tlimitmin) ||
647  (temptlimit > 2.*tlimit-tlimitmin));
648  }
649  else
650  temptlimit = tlimitmin;
651 
652  if(tPathLength > temptlimit) tPathLength = temptlimit;
653  }
654  else
655  if(tPathLength > tlimit) tPathLength = tlimit;
656  }
657 
658  // version similar to 7.1 (needed for some experiments)
659  else
660  {
661  if (stepStatus == fGeomBoundary)
662  {
663  if (currentRange > lambda0) tlimit = facrange*currentRange;
664  else tlimit = facrange*lambda0;
665 
666  if(tlimit < tlimitmin) tlimit = tlimitmin;
667  if(tPathLength > tlimit) tPathLength = tlimit;
668  }
669  }
670  //G4cout << "tPathLength= " << tPathLength
671  // << " currentMinimalStep= " << currentMinimalStep << G4endl;
672  return ConvertTrueToGeom(tPathLength, currentMinimalStep);
673 }
674 
675 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
676 
677 G4double QweakSimUrbanMscModel::ComputeGeomPathLength(G4double)
678 {
679  firstStep = false;
680  lambdaeff = lambda0;
681  par1 = -1. ;
682  par2 = par3 = 0. ;
683 
684  // do the true -> geom transformation
685  zPathLength = tPathLength;
686 
687  // z = t for very small tPathLength
688  if(tPathLength < tlimitminfix) return zPathLength;
689 
690  // this correction needed to run MSC with eIoni and eBrem inactivated
691  // and makes no harm for a normal run
692  // It is already checked
693  // if(tPathLength > currentRange)
694  // tPathLength = currentRange ;
695 
696  G4double tau = tPathLength/lambda0 ;
697 
698  if ((tau <= tausmall) || insideskin) {
699  zPathLength = tPathLength;
700  if(zPathLength > lambda0) zPathLength = lambda0;
701  return zPathLength;
702  }
703 
704  G4double zmean = tPathLength;
705  if (tPathLength < currentRange*dtrl) {
706  if(tau < taulim) zmean = tPathLength*(1.-0.5*tau) ;
707  else zmean = lambda0*(1.-exp(-tau));
708  zPathLength = zmean ;
709  return zPathLength;
710 
711  } else if(currentKinEnergy < mass || tPathLength == currentRange) {
712  par1 = 1./currentRange ;
713  par2 = 1./(par1*lambda0) ;
714  par3 = 1.+par2 ;
715  if(tPathLength < currentRange)
716  zmean = (1.-exp(par3*log(1.-tPathLength/currentRange)))/(par1*par3) ;
717  else {
718  zmean = 1./(par1*par3) ;
719  }
720  zPathLength = zmean ;
721  return zPathLength;
722 
723  } else {
724  G4double T1 = GetEnergy(particle,currentRange-tPathLength,couple);
725  G4double lambda1 = GetTransportMeanFreePath(particle,T1);
726 
727  par1 = (lambda0-lambda1)/(lambda0*tPathLength);
728  par2 = 1./(par1*lambda0);
729  par3 = 1.+par2 ;
730  zmean = (1.-exp(par3*log(lambda1/lambda0)))/(par1*par3);
731  }
732 
733  zPathLength = zmean;
734 
735  // sample z
736  if(samplez)
737  {
738  const G4double ztmax = 0.999 ;
739  G4double zt = zmean/tPathLength ;
740 
741  if (tPathLength > stepmin && zt < ztmax)
742  {
743  G4double u,cz1;
744  if(zt >= third)
745  {
746  G4double cz = 0.5*(3.*zt-1.)/(1.-zt) ;
747  cz1 = 1.+cz ;
748  G4double u0 = cz/cz1 ;
749  G4double grej ;
750  do {
751  u = exp(log(G4UniformRand())/cz1) ;
752  grej = exp(cz*log(u/u0))*(1.-u)/(1.-u0) ;
753  } while (grej < G4UniformRand()) ;
754  }
755  else
756  {
757  u = 2.*zt*G4UniformRand();
758  }
759  zPathLength = tPathLength*u ;
760  }
761  }
762 
763  if(zPathLength > lambda0) { zPathLength = lambda0; }
764  //G4cout<< "zPathLength= "<< zPathLength<< " lambda1= " << lambda0 << G4endl;
765  return zPathLength;
766 }
767 
768 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
769 
770 G4double QweakSimUrbanMscModel::ComputeTrueStepLength(G4double geomStepLength)
771 {
772  // step defined other than transportation
773  if(geomStepLength == zPathLength)
774  { return tPathLength; }
775 
776  zPathLength = geomStepLength;
777 
778  // t = z for very small step
779  if(geomStepLength < tlimitminfix) {
780  tPathLength = geomStepLength;
781 
782  // recalculation
783  } else {
784 
785  G4double tlength = geomStepLength;
786  if((geomStepLength > lambda0*tausmall) && !insideskin) {
787 
788  if(par1 < 0.) {
789  tlength = -lambda0*log(1.-geomStepLength/lambda0) ;
790  } else {
791  if(par1*par3*geomStepLength < 1.) {
792  tlength = (1.-exp(log(1.-par1*par3*geomStepLength)/par3))/par1 ;
793  } else {
794  tlength = currentRange;
795  }
796  }
797  if(tlength < geomStepLength) { tlength = geomStepLength; }
798  else if(tlength > tPathLength) { tlength = tPathLength; }
799  }
800  tPathLength = tlength;
801  }
802  //G4cout << "Urban96::ComputeTrueLength: tPathLength= " << tPathLength
803  // << " step= " << geomStepLength << G4endl;
804 
805  return tPathLength;
806 }
807 
808 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
809 
810 G4double QweakSimUrbanMscModel::ComputeTheta0(G4double trueStepLength,
811  G4double KineticEnergy)
812 {
813  // for all particles take the width of the central part
814  // from a parametrization similar to the Highland formula
815  // ( Highland formula: Particle Physics Booklet, July 2002, eq. 26.10)
816  static const G4double c_highland = 13.6*MeV ;
817  G4double betacp = sqrt(currentKinEnergy*(currentKinEnergy+2.*mass)*
818  KineticEnergy*(KineticEnergy+2.*mass)/
819  ((currentKinEnergy+mass)*(KineticEnergy+mass)));
820  y = trueStepLength/currentRadLength;
821  G4double theta0 = c_highland*std::abs(charge)*sqrt(y)/betacp;
822  y = log(y);
823  // correction factor from e- scattering data
824  G4double corr = coeffth1+coeffth2*y;
825 
826  theta0 *= corr ;
827 
828  return theta0;
829 }
830 
831 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
832 
833 G4ThreeVector&
834 QweakSimUrbanMscModel::SampleScattering(const G4ThreeVector& oldDirection,
835  G4double safety)
836 {
837  fDisplacement.set(0.0,0.0,0.0);
838  G4double kineticEnergy = currentKinEnergy;
839  if (tPathLength > currentRange*dtrl) {
840  kineticEnergy = GetEnergy(particle,currentRange-tPathLength,couple);
841  } else {
842  kineticEnergy -= tPathLength*GetDEDX(particle,currentKinEnergy,couple);
843  }
844 
845  if((kineticEnergy <= eV) || (tPathLength <= tlimitminfix) ||
846  (tPathLength/tausmall < lambda0)) { return fDisplacement; }
847 
848  G4double cth = SampleCosineTheta(tPathLength,kineticEnergy);
849 
850  // protection against 'bad' cth values
851  if(std::fabs(cth) > 1.) { return fDisplacement; }
852 
853  // extra protection agaist high energy particles backscattered
854  //G4cout << "Warning: large scattering E(MeV)= " << kineticEnergy
855  // << " s(mm)= " << tPathLength/mm
856  // << " 1-cosTheta= " << 1.0 - cth << G4endl;
857  // do Gaussian central scattering
858  // if(kineticEnergy > 5*GeV && cth < 0.9) {
859  /*
860  if(cth < 1.0 - 1000*tPathLength/lambda0
861  && cth < 0.8 && kineticEnergy > 20*MeV) {
862  G4ExceptionDescription ed;
863  ed << particle->GetParticleName()
864  << " E(MeV)= " << kineticEnergy/MeV
865  << " Step(mm)= " << tPathLength/mm
866  << " in " << CurrentCouple()->GetMaterial()->GetName()
867  << " CosTheta= " << cth
868  << " is too big";
869  G4Exception("QweakSimUrbanMscModel::SampleScattering","em0004",
870  JustWarning, ed,"");
871 
872  if(kineticEnergy > GeV && cth < 0.0) {
873  do {
874  cth = 1.0 + 2*log(G4UniformRand())*tPathLength/lambda0;
875  } while(cth < -1.0);
876  }
877 */
878 
879  G4double sth = sqrt((1.0 - cth)*(1.0 + cth));
880  G4double phi = twopi*G4UniformRand();
881  if(ePolarized){//FIXME
882  if(debugPrint) G4cout<<" Urban fix "<<G4endl;
883  G4double _prob=G4UniformRand();
884  G4double _amplitude=1.0/eEnergy * sth *
885  sqrt(pow(polarization.getX(),2)+pow(polarization.getY(),2));//scale by transvers polarization
886  if(_amplitude > 1 ) _amplitude=1;
887  if( _prob < _amplitude * sin(phi-pi) )
888  phi-=pi;
889  phi+= polarization.getPhi() - oldDirection.getPhi();
890  if(phi<0) phi+=twopi;
891  else if(phi>twopi) phi=fmod(phi,twopi);
892  }//FIXME
893 
894  G4double dirx = sth*cos(phi);
895  G4double diry = sth*sin(phi);
896 
897  G4ThreeVector newDirection(dirx,diry,cth);
898  newDirection.rotateUz(oldDirection);
899  fParticleChange->ProposeMomentumDirection(newDirection);
900 
901  //FIXME
902  if(debugPrint){
903  G4cout<<" Urban96 cth, th, phi old.angle(new)" << cth << " " << acos(cth) << " " << phi << " " <<oldDirection.angle(newDirection) << G4endl;
904  G4cout<<" Urban96: old dir: R th phi "<<oldDirection.getR()<<" "<<oldDirection.getTheta()<<" "<<oldDirection.getPhi()<<G4endl;
905  G4cout<<" Urban96: new dir: R th phi "<<newDirection.getR()<<" "<<newDirection.getTheta()<<" "<<newDirection.getPhi()<<G4endl;
906  }//FIXME
907  /*
908  G4cout << "QweakSimUrbanMscModel::SampleSecondaries: e(MeV)= " << kineticEnergy
909  << " sinTheta= " << sth << " safety(mm)= " << safety
910  << " trueStep(mm)= " << tPathLength
911  << " geomStep(mm)= " << zPathLength
912  << G4endl;
913  */
914  if (latDisplasment && safety > tlimitminfix) {
915 
916  G4double r = SampleDisplacement();
917  /*
918  G4cout << "QweakSimUrbanMscModel::SampleSecondaries: e(MeV)= " << kineticEnergy
919  << " sinTheta= " << sth << " r(mm)= " << r
920  << " trueStep(mm)= " << tPathLength
921  << " geomStep(mm)= " << zPathLength
922  << G4endl;
923  */
924  if(r > 0.)
925  {
926  G4double latcorr = LatCorrelation();
927  if(latcorr > r) latcorr = r;
928 
929  // sample direction of lateral displacement
930  // compute it from the lateral correlation
931  G4double Phi = 0.;
932  if(std::abs(r*sth) < latcorr)
933  Phi = twopi*G4UniformRand();
934  else
935  {
936  G4double psi = std::acos(latcorr/(r*sth));
937  if(G4UniformRand() < 0.5)
938  Phi = phi+psi;
939  else
940  Phi = phi-psi;
941  }
942 
943  dirx = std::cos(Phi);
944  diry = std::sin(Phi);
945 
946  fDisplacement.set(r*dirx,r*diry,0.0);
947  fDisplacement.rotateUz(oldDirection);
948  }
949  }
950  return fDisplacement;
951 }
952 
953 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
954 
955 G4double QweakSimUrbanMscModel::SampleCosineTheta(G4double trueStepLength,
956  G4double KineticEnergy)
957 {
958  G4double cth = 1. ;
959  G4double tau = trueStepLength/lambda0;
960  currentTau = tau;
961  lambdaeff = lambda0;
962 
963  Zeff = couple->GetMaterial()->GetTotNbOfElectPerVolume()/
964  couple->GetMaterial()->GetTotNbOfAtomsPerVolume() ;
965 
966  if(Zold != Zeff)
967  UpdateCache();
968 
969  G4double lambda1 = GetTransportMeanFreePath(particle,KineticEnergy);
970  if(std::fabs(lambda1/lambda0 - 1) > 0.01 && lambda1 > 0.)
971  {
972  // mean tau value
973  tau = trueStepLength*log(lambda0/lambda1)/(lambda0-lambda1);
974  }
975 
976  currentTau = tau ;
977  lambdaeff = trueStepLength/currentTau;
978  currentRadLength = couple->GetMaterial()->GetRadlen();
979 
980  if (tau >= taubig) { cth = -1.+2.*G4UniformRand(); }
981  else if (tau >= tausmall) {
982  static const G4double numlim = 0.01;
983  G4double xmeanth, x2meanth;
984  if(tau < numlim) {
985  xmeanth = 1.0 - tau*(1.0 - 0.5*tau);
986  x2meanth= 1.0 - tau*(5.0 - 6.25*tau)/3.;
987  } else {
988  xmeanth = exp(-tau);
989  x2meanth = (1.+2.*exp(-2.5*tau))/3.;
990  }
991  G4double relloss = 1.-KineticEnergy/currentKinEnergy;
992 
993  if(relloss > rellossmax)
994  return SimpleScattering(xmeanth,x2meanth);
995 
996  // is step extreme small ?
997  G4bool extremesmallstep = false ;
998  G4double tsmall = tlimitmin ;
999  G4double theta0 = 0.;
1000  if(trueStepLength > tsmall) {
1001  theta0 = ComputeTheta0(trueStepLength,KineticEnergy);
1002  } else {
1003  G4double rate = trueStepLength/tsmall ;
1004  if(G4UniformRand() < rate) {
1005  theta0 = ComputeTheta0(tsmall,KineticEnergy);
1006  extremesmallstep = true ;
1007  }
1008  }
1009  //G4cout << "Theta0= " << theta0 << " theta0max= " << theta0max
1010  // << " sqrt(tausmall)= " << sqrt(tausmall) << G4endl;
1011 
1012  // protection for very small angles
1013  G4double theta2 = theta0*theta0;
1014 
1015  if(theta2 < tausmall) { return cth; }
1016 
1017  if(theta0 > theta0max) {
1018  return SimpleScattering(xmeanth,x2meanth);
1019  }
1020 
1021  G4double x = theta2*(1.0 - theta2/12.);
1022  if(theta2 > numlim) {
1023  G4double sth = 2*sin(0.5*theta0);
1024  x = sth*sth;
1025  }
1026 
1027  // parameter for tail
1028  G4double ltau= log(tau);
1029  G4double u = exp(ltau/6.);
1030  if(extremesmallstep) u = exp(log(tsmall/lambda0)/6.);
1031  G4double xx = log(lambdaeff/currentRadLength);
1032  G4double xsi = coeffc1+u*(coeffc2+coeffc3*u)+coeffc4*xx;
1033 
1034  // tail should not be too big
1035  if(xsi < 1.9) {
1036  /*
1037  if(KineticEnergy > 20*MeV && xsi < 1.6) {
1038  G4cout << "QweakSimUrbanMscModel::SampleCosineTheta: E(GeV)= "
1039  << KineticEnergy/GeV
1040  << " !!** c= " << xsi
1041  << " **!! length(mm)= " << trueStepLength << " Zeff= " << Zeff
1042  << " " << couple->GetMaterial()->GetName()
1043  << " tau= " << tau << G4endl;
1044  }
1045  */
1046  xsi = 1.9;
1047  }
1048 
1049  G4double c = xsi;
1050 
1051  if(fabs(c-3.) < 0.001) { c = 3.001; }
1052  else if(fabs(c-2.) < 0.001) { c = 2.001; }
1053 
1054  G4double c1 = c-1.;
1055 
1056  G4double ea = exp(-xsi);
1057  G4double eaa = 1.-ea ;
1058  G4double xmean1 = 1.-(1.-(1.+xsi)*ea)*x/eaa;
1059  G4double x0 = 1. - xsi*x;
1060 
1061  // G4cout << " xmean1= " << xmean1 << " xmeanth= " << xmeanth << G4endl;
1062 
1063  if(xmean1 <= 0.999*xmeanth) {
1064  return SimpleScattering(xmeanth,x2meanth);
1065  }
1066  //from continuity of derivatives
1067  G4double b = 1.+(c-xsi)*x;
1068 
1069  G4double b1 = b+1.;
1070  G4double bx = c*x;
1071 
1072  G4double eb1 = pow(b1,c1);
1073  G4double ebx = pow(bx,c1);
1074  G4double d = ebx/eb1;
1075 
1076  G4double xmean2 = (x0 + d - (bx - b1*d)/(c-2.))/(1. - d);
1077 
1078  G4double f1x0 = ea/eaa;
1079  G4double f2x0 = c1/(c*(1. - d));
1080  G4double prob = f2x0/(f1x0+f2x0);
1081 
1082  G4double qprob = xmeanth/(prob*xmean1+(1.-prob)*xmean2);
1083 
1084  // sampling of costheta
1085  //G4cout << "c= " << c << " qprob= " << qprob << " eb1= " << eb1
1086  // << " c1= " << c1 << " b1= " << b1 << " bx= " << bx << " eb1= " << eb1
1087  // << G4endl;
1088  if(G4UniformRand() < qprob)
1089  {
1090  G4double var = 0;
1091  if(G4UniformRand() < prob) {
1092  cth = 1.+log(ea+G4UniformRand()*eaa)*x;
1093  } else {
1094  var = (1.0 - d)*G4UniformRand();
1095  if(var < numlim*d) {
1096  var /= (d*c1);
1097  cth = -1.0 + var*(1.0 - 0.5*var*c)*(2. + (c - xsi)*x);
1098  } else {
1099  cth = 1. + x*(c - xsi - c*pow(var + d, -1.0/c1));
1100  //b-b1*bx/exp(log(ebx+(eb1-ebx)*G4UniformRand())/c1) ;
1101  }
1102  }
1103  if(KineticEnergy > 5*GeV && cth < 0.9) {
1104  G4cout << "QweakSimUrbanMscModel::SampleCosineTheta: E(GeV)= "
1105  << KineticEnergy/GeV
1106  << " 1-cosT= " << 1 - cth
1107  << " length(mm)= " << trueStepLength << " Zeff= " << Zeff
1108  << " tau= " << tau
1109  << " prob= " << prob << " var= " << var << G4endl;
1110  G4cout << " c= " << c << " qprob= " << qprob << " eb1= " << eb1
1111  << " ebx= " << ebx
1112  << " c1= " << c1 << " b= " << b << " b1= " << b1
1113  << " bx= " << bx << " d= " << d
1114  << " ea= " << ea << " eaa= " << eaa << G4endl;
1115  }
1116  }
1117  else {
1118  cth = -1.+2.*G4UniformRand();
1119  if(KineticEnergy > 5*GeV) {
1120  G4cout << "QweakSimUrbanMscModel::SampleCosineTheta: E(GeV)= "
1121  << KineticEnergy/GeV
1122  << " length(mm)= " << trueStepLength << " Zeff= " << Zeff
1123  << " qprob= " << qprob << G4endl;
1124  }
1125  }
1126  }
1127  return cth ;
1128 }
1129 
1130 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
1131 
1132 G4double QweakSimUrbanMscModel::SimpleScattering(G4double xmeanth,G4double x2meanth)
1133 {
1134  // 'large angle scattering'
1135  // 2 model functions with correct xmean and x2mean
1136  G4double a = (2.*xmeanth+9.*x2meanth-3.)/(2.*xmeanth-3.*x2meanth+1.);
1137  G4double prob = (a+2.)*xmeanth/a;
1138 
1139  // sampling
1140  G4double cth = 1.;
1141  if(G4UniformRand() < prob)
1142  cth = -1.+2.*exp(log(G4UniformRand())/(a+1.));
1143  else
1144  cth = -1.+2.*G4UniformRand();
1145  return cth;
1146 }
1147 
1148 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
1149 
1150 G4double QweakSimUrbanMscModel::SampleDisplacement()
1151 {
1152  G4double r = 0.0;
1153  if ((currentTau >= tausmall) && !insideskin) {
1154  G4double rmax = sqrt((tPathLength-zPathLength)*(tPathLength+zPathLength));
1155  r = rmax*exp(log(G4UniformRand())/3.);
1156  }
1157  return r;
1158 }
1159 
1160 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
1161 
1162 G4double QweakSimUrbanMscModel::LatCorrelation()
1163 {
1164  static const G4double kappa = 2.5;
1165  static const G4double kappami1 = kappa-1.;
1166 
1167  G4double latcorr = 0.;
1168  if((currentTau >= tausmall) && !insideskin)
1169  {
1170  if(currentTau < taulim)
1171  latcorr = lambdaeff*kappa*currentTau*currentTau*
1172  (1.-(kappa+1.)*currentTau/3.)/3.;
1173  else
1174  {
1175  G4double etau = 0.;
1176  if(currentTau < taubig) etau = exp(-currentTau);
1177  latcorr = -kappa*currentTau;
1178  latcorr = exp(latcorr)/kappami1;
1179  latcorr += 1.-kappa*etau/kappami1 ;
1180  latcorr *= 2.*lambdaeff/3. ;
1181  }
1182  }
1183 
1184  return latcorr;
1185 }
1186 
1187 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
QweakSimUrbanMscModel::theManager
G4LossTableManager * theManager
Definition: QweakSimUrbanMscModel.hh:124
QweakSimUrbanMscModel::ComputeCrossSectionPerAtom
G4double ComputeCrossSectionPerAtom(const G4ParticleDefinition *particle, G4double KineticEnergy, G4double AtomicNumber, G4double AtomicWeight=0., G4double cut=0., G4double emax=DBL_MAX)
Definition: QweakSimUrbanMscModel.cc:168
QweakSimUrbanMscModel::ComputeTheta0
G4double ComputeTheta0(G4double truePathLength, G4double KineticEnergy)
Definition: QweakSimUrbanMscModel.cc:810
QweakSimUrbanMscModel::SetParticle
void SetParticle(const G4ParticleDefinition *)
Definition: QweakSimUrbanMscModel.hh:186
QweakSimUrbanMscModel::SimpleScattering
G4double SimpleScattering(G4double xmeanth, G4double x2meanth)
Definition: QweakSimUrbanMscModel.cc:1132
QweakSimUrbanMscModel::SampleScattering
G4ThreeVector & SampleScattering(const G4ThreeVector &, G4double safety)
Definition: QweakSimUrbanMscModel.cc:834
QweakSimUrbanMscModel::fParticleChange
G4ParticleChangeForMSC * fParticleChange
Definition: QweakSimUrbanMscModel.hh:121
QweakSimUrbanMscModel::ComputeTrueStepLength
G4double ComputeTrueStepLength(G4double geomStepLength)
Definition: QweakSimUrbanMscModel.cc:770
QweakSimUrbanMscModel::ComputeTruePathLengthLimit
G4double ComputeTruePathLengthLimit(const G4Track &track, G4double &currentMinimalStep)
Definition: QweakSimUrbanMscModel.cc:426
QweakSimUrbanMscModel::Initialise
void Initialise(const G4ParticleDefinition *, const G4DataVector &)
Definition: QweakSimUrbanMscModel.cc:144
QweakSimUrbanMscModel::ComputeGeomPathLength
G4double ComputeGeomPathLength(G4double truePathLength)
Definition: QweakSimUrbanMscModel.cc:677
QweakSimUrbanMscModel::QweakSimUrbanMscModel
QweakSimUrbanMscModel(const G4String &nam="UrbanMsc96")
Definition: QweakSimUrbanMscModel.cc:77
QweakSimUrbanMscModel::couple
const G4MaterialCutsCouple * couple
Definition: QweakSimUrbanMscModel.hh:123
QweakSimUrbanMscModel::SampleCosineTheta
G4double SampleCosineTheta(G4double trueStepLength, G4double KineticEnergy)
Definition: QweakSimUrbanMscModel.cc:955
QweakSimUrbanMscModel::particle
const G4ParticleDefinition * particle
Definition: QweakSimUrbanMscModel.hh:120