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G4UrbanMscModel96 Class Reference
#include <G4UrbanMscModel96.hh>
Inheritance diagram for G4UrbanMscModel96:
Detailed Description
Definition at line 65 of file G4UrbanMscModel96.hh.
Constructor & Destructor Documentation
◆ G4UrbanMscModel96()
Definition at line 72 of file G4UrbanMscModel96.cc.
73 : G4VMscModel(nam)
74{
75 masslimite = 0.6*MeV;
76 lambdalimit = 1.*mm;
77 fr = 0.02;
78 taubig = 8.0;
79 tausmall = 1.e-16;
80 taulim = 1.e-6;
81 currentTau = taulim;
82 tlimitminfix = 1.e-6*mm;
83 stepmin = tlimitminfix;
84 smallstep = 1.e10;
85 currentRange = 0. ;
86 rangeinit = 0.;
87 tlimit = 1.e10*mm;
88 tlimitmin = 10.*tlimitminfix;
89 tgeom = 1.e50*mm;
90 geombig = 1.e50*mm;
91 geommin = 1.e-3*mm;
92 geomlimit = geombig;
93 presafety = 0.*mm;
94 //facsafety = 0.50 ;
95
96 y = 0.;
97 z = 0.;
98
99 Zold = 0.;
100 Zeff = 1.;
101 Z2 = 1.;
102 Z23 = 1.;
103 lnZ = 0.;
104
105 coeffc1 = 0.;
106 coeffc2 = 0.;
107 coeffc3 = 0.;
108 coeffc4 = 0.;
109 scr1ini = fine_structure_const*fine_structure_const*
110 electron_mass_c2*electron_mass_c2/(0.885*0.885*4.*pi);
111 scr2ini = 3.76*fine_structure_const*fine_structure_const;
112 scr1 = 0.;
113 scr2 = 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;
135}
static G4LossTableManager * Instance()
Definition: G4LossTableManager.cc:107
Definition: G4VMscModel.hh:69
◆ ~G4UrbanMscModel96()
|
virtual |
Definition at line 139 of file G4UrbanMscModel96.cc.
140{}
Member Function Documentation
◆ ComputeCrossSectionPerAtom()
|
virtual |
Reimplemented from G4VEmModel.
Definition at line 168 of file G4UrbanMscModel96.cc.
173{
176 Bohr_radius*Bohr_radius/(hbarc*hbarc);
178
180 50., 56., 64., 74., 79., 82. };
181
183 1*keV, 2*keV, 4*keV, 7*keV,
184 10*keV, 20*keV, 40*keV, 70*keV,
185 100*keV, 200*keV, 400*keV, 700*keV,
186 1*MeV, 2*MeV, 4*MeV, 7*MeV,
187 10*MeV, 20*MeV};
188
189 // corr. factors for e-/e+ lambda for T <= Tlim
190 G4double celectron[15][22] =
191 {{1.125,1.072,1.051,1.047,1.047,1.050,1.052,1.054,
192 1.054,1.057,1.062,1.069,1.075,1.090,1.105,1.111,
193 1.112,1.108,1.100,1.093,1.089,1.087 },
194 {1.408,1.246,1.143,1.096,1.077,1.059,1.053,1.051,
195 1.052,1.053,1.058,1.065,1.072,1.087,1.101,1.108,
196 1.109,1.105,1.097,1.090,1.086,1.082 },
197 {2.833,2.268,1.861,1.612,1.486,1.309,1.204,1.156,
198 1.136,1.114,1.106,1.106,1.109,1.119,1.129,1.132,
199 1.131,1.124,1.113,1.104,1.099,1.098 },
200 {3.879,3.016,2.380,2.007,1.818,1.535,1.340,1.236,
201 1.190,1.133,1.107,1.099,1.098,1.103,1.110,1.113,
202 1.112,1.105,1.096,1.089,1.085,1.098 },
203 {6.937,4.330,2.886,2.256,1.987,1.628,1.395,1.265,
204 1.203,1.122,1.080,1.065,1.061,1.063,1.070,1.073,
205 1.073,1.070,1.064,1.059,1.056,1.056 },
206 {9.616,5.708,3.424,2.551,2.204,1.762,1.485,1.330,
207 1.256,1.155,1.099,1.077,1.070,1.068,1.072,1.074,
208 1.074,1.070,1.063,1.059,1.056,1.052 },
209 {11.72,6.364,3.811,2.806,2.401,1.884,1.564,1.386,
210 1.300,1.180,1.112,1.082,1.073,1.066,1.068,1.069,
211 1.068,1.064,1.059,1.054,1.051,1.050 },
212 {18.08,8.601,4.569,3.183,2.662,2.025,1.646,1.439,
213 1.339,1.195,1.108,1.068,1.053,1.040,1.039,1.039,
214 1.039,1.037,1.034,1.031,1.030,1.036 },
215 {18.22,10.48,5.333,3.713,3.115,2.367,1.898,1.631,
216 1.498,1.301,1.171,1.105,1.077,1.048,1.036,1.033,
217 1.031,1.028,1.024,1.022,1.021,1.024 },
218 {14.14,10.65,5.710,3.929,3.266,2.453,1.951,1.669,
219 1.528,1.319,1.178,1.106,1.075,1.040,1.027,1.022,
220 1.020,1.017,1.015,1.013,1.013,1.020 },
221 {14.11,11.73,6.312,4.240,3.478,2.566,2.022,1.720,
222 1.569,1.342,1.186,1.102,1.065,1.022,1.003,0.997,
223 0.995,0.993,0.993,0.993,0.993,1.011 },
224 {22.76,20.01,8.835,5.287,4.144,2.901,2.219,1.855,
225 1.677,1.410,1.224,1.121,1.073,1.014,0.986,0.976,
226 0.974,0.972,0.973,0.974,0.975,0.987 },
227 {50.77,40.85,14.13,7.184,5.284,3.435,2.520,2.059,
228 1.837,1.512,1.283,1.153,1.091,1.010,0.969,0.954,
229 0.950,0.947,0.949,0.952,0.954,0.963 },
230 {65.87,59.06,15.87,7.570,5.567,3.650,2.682,2.182,
231 1.939,1.579,1.325,1.178,1.108,1.014,0.965,0.947,
232 0.941,0.938,0.940,0.944,0.946,0.954 },
233 {55.60,47.34,15.92,7.810,5.755,3.767,2.760,2.239,
234 1.985,1.609,1.343,1.188,1.113,1.013,0.960,0.939,
235 0.933,0.930,0.933,0.936,0.939,0.949 }};
236
237 G4double cpositron[15][22] = {
238 {2.589,2.044,1.658,1.446,1.347,1.217,1.144,1.110,
239 1.097,1.083,1.080,1.086,1.092,1.108,1.123,1.131,
240 1.131,1.126,1.117,1.108,1.103,1.100 },
241 {3.904,2.794,2.079,1.710,1.543,1.325,1.202,1.145,
242 1.122,1.096,1.089,1.092,1.098,1.114,1.130,1.137,
243 1.138,1.132,1.122,1.113,1.108,1.102 },
244 {7.970,6.080,4.442,3.398,2.872,2.127,1.672,1.451,
245 1.357,1.246,1.194,1.179,1.178,1.188,1.201,1.205,
246 1.203,1.190,1.173,1.159,1.151,1.145 },
247 {9.714,7.607,5.747,4.493,3.815,2.777,2.079,1.715,
248 1.553,1.353,1.253,1.219,1.211,1.214,1.225,1.228,
249 1.225,1.210,1.191,1.175,1.166,1.174 },
250 {17.97,12.95,8.628,6.065,4.849,3.222,2.275,1.820,
251 1.624,1.382,1.259,1.214,1.202,1.202,1.214,1.219,
252 1.217,1.203,1.184,1.169,1.160,1.151 },
253 {24.83,17.06,10.84,7.355,5.767,3.707,2.546,1.996,
254 1.759,1.465,1.311,1.252,1.234,1.228,1.238,1.241,
255 1.237,1.222,1.201,1.184,1.174,1.159 },
256 {23.26,17.15,11.52,8.049,6.375,4.114,2.792,2.155,
257 1.880,1.535,1.353,1.281,1.258,1.247,1.254,1.256,
258 1.252,1.234,1.212,1.194,1.183,1.170 },
259 {22.33,18.01,12.86,9.212,7.336,4.702,3.117,2.348,
260 2.015,1.602,1.385,1.297,1.268,1.251,1.256,1.258,
261 1.254,1.237,1.214,1.195,1.185,1.179 },
262 {33.91,24.13,15.71,10.80,8.507,5.467,3.692,2.808,
263 2.407,1.873,1.564,1.425,1.374,1.330,1.324,1.320,
264 1.312,1.288,1.258,1.235,1.221,1.205 },
265 {32.14,24.11,16.30,11.40,9.015,5.782,3.868,2.917,
266 2.490,1.925,1.596,1.447,1.391,1.342,1.332,1.327,
267 1.320,1.294,1.264,1.240,1.226,1.214 },
268 {29.51,24.07,17.19,12.28,9.766,6.238,4.112,3.066,
269 2.602,1.995,1.641,1.477,1.414,1.356,1.342,1.336,
270 1.328,1.302,1.270,1.245,1.231,1.233 },
271 {38.19,30.85,21.76,15.35,12.07,7.521,4.812,3.498,
272 2.926,2.188,1.763,1.563,1.484,1.405,1.382,1.371,
273 1.361,1.330,1.294,1.267,1.251,1.239 },
274 {49.71,39.80,27.96,19.63,15.36,9.407,5.863,4.155,
275 3.417,2.478,1.944,1.692,1.589,1.480,1.441,1.423,
276 1.409,1.372,1.330,1.298,1.280,1.258 },
277 {59.25,45.08,30.36,20.83,16.15,9.834,6.166,4.407,
278 3.641,2.648,2.064,1.779,1.661,1.531,1.482,1.459,
279 1.442,1.400,1.354,1.319,1.299,1.272 },
280 {56.38,44.29,30.50,21.18,16.51,10.11,6.354,4.542,
281 3.752,2.724,2.116,1.817,1.692,1.554,1.499,1.474,
282 1.456,1.412,1.364,1.328,1.307,1.282 }};
283
284 //data/corrections for T > Tlim
285 G4double Tlim = 10.*MeV;
286 G4double beta2lim = Tlim*(Tlim+2.*electron_mass_c2)/
287 ((Tlim+electron_mass_c2)*(Tlim+electron_mass_c2));
288 G4double bg2lim = Tlim*(Tlim+2.*electron_mass_c2)/
289 (electron_mass_c2*electron_mass_c2);
290
291 G4double sig0[15] = {0.2672*barn, 0.5922*barn, 2.653*barn, 6.235*barn,
292 11.69*barn , 13.24*barn , 16.12*barn, 23.00*barn ,
293 35.13*barn , 39.95*barn , 50.85*barn, 67.19*barn ,
294 91.15*barn , 104.4*barn , 113.1*barn};
295
296 G4double hecorr[15] = {120.70, 117.50, 105.00, 92.92, 79.23, 74.510, 68.29,
297 57.39, 41.97, 36.14, 24.53, 10.21, -7.855, -16.84,
298 -22.30};
299
300 G4double sigma;
301 SetParticle(part);
302
303 Z23 = pow(AtomicNumber,2./3.);
304
305 // correction if particle .ne. e-/e+
306 // compute equivalent kinetic energy
307 // lambda depends on p*beta ....
308
309 G4double eKineticEnergy = KineticEnergy;
310
311 if(mass > electron_mass_c2)
312 {
313 G4double TAU = KineticEnergy/mass ;
314 G4double c = mass*TAU*(TAU+2.)/(electron_mass_c2*(TAU+1.)) ;
315 G4double w = c-2. ;
316 G4double tau = 0.5*(w+sqrt(w*w+4.*c)) ;
317 eKineticEnergy = electron_mass_c2*tau ;
318 }
319
320 G4double eTotalEnergy = eKineticEnergy + electron_mass_c2 ;
321 G4double beta2 = eKineticEnergy*(eTotalEnergy+electron_mass_c2)
322 /(eTotalEnergy*eTotalEnergy);
323 G4double bg2 = eKineticEnergy*(eTotalEnergy+electron_mass_c2)
324 /(electron_mass_c2*electron_mass_c2);
325
326 G4double eps = epsfactor*bg2/Z23;
327
328 if (eps<epsmin) sigma = 2.*eps*eps;
329 else if(eps<epsmax) sigma = log(1.+2.*eps)-2.*eps/(1.+2.*eps);
330 else sigma = log(2.*eps)-1.+1./eps;
331
332 sigma *= ChargeSquare*AtomicNumber*AtomicNumber/(beta2*bg2);
333
334 // interpolate in AtomicNumber and beta2
335 G4double c1,c2,cc1,cc2,corr;
336
337 // get bin number in Z
338 G4int iZ = 14;
339 while ((iZ>=0)&&(Zdat[iZ]>=AtomicNumber)) iZ -= 1;
340 if (iZ==14) iZ = 13;
341 if (iZ==-1) iZ = 0 ;
342
343 G4double ZZ1 = Zdat[iZ];
344 G4double ZZ2 = Zdat[iZ+1];
345 G4double ratZ = (AtomicNumber-ZZ1)*(AtomicNumber+ZZ1)/
346 ((ZZ2-ZZ1)*(ZZ2+ZZ1));
347
348 if(eKineticEnergy <= Tlim)
349 {
350 // get bin number in T (beta2)
351 G4int iT = 21;
352 while ((iT>=0)&&(Tdat[iT]>=eKineticEnergy)) iT -= 1;
353 if(iT==21) iT = 20;
354 if(iT==-1) iT = 0 ;
355
356 // calculate betasquare values
357 G4double T = Tdat[iT], E = T + electron_mass_c2;
358 G4double b2small = T*(E+electron_mass_c2)/(E*E);
359
360 T = Tdat[iT+1]; E = T + electron_mass_c2;
361 G4double b2big = T*(E+electron_mass_c2)/(E*E);
362 G4double ratb2 = (beta2-b2small)/(b2big-b2small);
363
364 if (charge < 0.)
365 {
366 c1 = celectron[iZ][iT];
367 c2 = celectron[iZ+1][iT];
368 cc1 = c1+ratZ*(c2-c1);
369
370 c1 = celectron[iZ][iT+1];
371 c2 = celectron[iZ+1][iT+1];
372 cc2 = c1+ratZ*(c2-c1);
373
374 corr = cc1+ratb2*(cc2-cc1);
375
376 sigma *= sigmafactor/corr;
377 }
378 else
379 {
380 c1 = cpositron[iZ][iT];
381 c2 = cpositron[iZ+1][iT];
382 cc1 = c1+ratZ*(c2-c1);
383
384 c1 = cpositron[iZ][iT+1];
385 c2 = cpositron[iZ+1][iT+1];
386 cc2 = c1+ratZ*(c2-c1);
387
388 corr = cc1+ratb2*(cc2-cc1);
389
390 sigma *= sigmafactor/corr;
391 }
392 }
393 else
394 {
395 c1 = bg2lim*sig0[iZ]*(1.+hecorr[iZ]*(beta2-beta2lim))/bg2;
396 c2 = bg2lim*sig0[iZ+1]*(1.+hecorr[iZ+1]*(beta2-beta2lim))/bg2;
397 if((AtomicNumber >= ZZ1) && (AtomicNumber <= ZZ2))
398 sigma = c1+ratZ*(c2-c1) ;
399 else if(AtomicNumber < ZZ1)
400 sigma = AtomicNumber*AtomicNumber*c1/(ZZ1*ZZ1);
401 else if(AtomicNumber > ZZ2)
402 sigma = AtomicNumber*AtomicNumber*c2/(ZZ2*ZZ2);
403 }
404 return sigma;
405
406}
◆ ComputeGeomPathLength()
Reimplemented from G4VMscModel.
Definition at line 642 of file G4UrbanMscModel96.cc.
643{
644 firstStep = false;
645 lambdaeff = lambda0;
646 par1 = -1. ;
647 par2 = par3 = 0. ;
648
649 // do the true -> geom transformation
650 zPathLength = tPathLength;
651
652 // z = t for very small tPathLength
653 if(tPathLength < tlimitminfix) return zPathLength;
654
655 // this correction needed to run MSC with eIoni and eBrem inactivated
656 // and makes no harm for a normal run
657 if(tPathLength > currentRange)
658 tPathLength = currentRange ;
659
660 G4double tau = tPathLength/lambda0 ;
661
662 if ((tau <= tausmall) || insideskin) {
663 zPathLength = tPathLength;
664 if(zPathLength > lambda0) zPathLength = lambda0;
665 return zPathLength;
666 }
667
668 G4double zmean = tPathLength;
670 if(tau < taulim) zmean = tPathLength*(1.-0.5*tau) ;
671 else zmean = lambda0*(1.-exp(-tau));
672 zPathLength = zmean ;
673 return zPathLength;
674
675 } else if(currentKinEnergy < mass || tPathLength == currentRange) {
676 par1 = 1./currentRange ;
677 par2 = 1./(par1*lambda0) ;
678 par3 = 1.+par2 ;
679 if(tPathLength < currentRange)
680 zmean = (1.-exp(par3*log(1.-tPathLength/currentRange)))/(par1*par3) ;
681 else {
682 zmean = 1./(par1*par3) ;
683 }
684 zPathLength = zmean ;
685 return zPathLength;
686
687 } else {
690
691 par1 = (lambda0-lambda1)/(lambda0*tPathLength) ;
692 par2 = 1./(par1*lambda0) ;
693 par3 = 1.+par2 ;
694 zmean = (1.-exp(par3*log(lambda1/lambda0)))/(par1*par3) ;
695 }
696
697 zPathLength = zmean ;
698
699 // sample z
701 {
703 G4double zt = zmean/tPathLength ;
704
705 if (tPathLength > stepmin && zt < ztmax)
706 {
707 G4double u,cz1;
708 if(zt >= third)
709 {
710 G4double cz = 0.5*(3.*zt-1.)/(1.-zt) ;
711 cz1 = 1.+cz ;
712 G4double u0 = cz/cz1 ;
713 G4double grej ;
714 do {
715 u = exp(log(G4UniformRand())/cz1) ;
716 grej = exp(cz*log(u/u0))*(1.-u)/(1.-u0) ;
718 }
719 else
720 {
721 u = 2.*zt*G4UniformRand();
722 }
723 if(u > 1.0) { u = 1.0; }
724 zPathLength = tPathLength*u ;
725 }
726 }
727
728 if(zPathLength > lambda0) { zPathLength = lambda0; }
729 //G4cout << "zPathLength= " << zPathLength << " lambda1= " << lambda0 << G4endl;
730 return zPathLength;
731}
G4double GetTransportMeanFreePath(const G4ParticleDefinition *part, G4double kinEnergy)
Definition: G4VMscModel.hh:332
G4double GetEnergy(const G4ParticleDefinition *part, G4double range, const G4MaterialCutsCouple *couple)
Definition: G4VMscModel.hh:304
◆ ComputeTheta0()
Definition at line 774 of file G4UrbanMscModel96.cc.
776{
777 // for all particles take the width of the central part
778 // from a parametrization similar to the Highland formula
779 // ( Highland formula: Particle Physics Booklet, July 2002, eq. 26.10)
781 G4double betacp = sqrt(currentKinEnergy*(currentKinEnergy+2.*mass)*
782 KineticEnergy*(KineticEnergy+2.*mass)/
783 ((currentKinEnergy+mass)*(KineticEnergy+mass)));
784 y = trueStepLength/currentRadLength;
785 G4double theta0 = c_highland*std::abs(charge)*sqrt(y)/betacp;
786 y = log(y);
787 z = log(currentTau)-y;
788
789 // correction factor from e- scattering data
790 G4double corr = 1.0925*exp(8.05922e-2*y)*(1.+1.06221e-2*z);
791 if(y > -5.5) corr += 3.47658e-2*exp(3.*log(y+5.5))*(1.+1.33868*z);
792
793
794 theta0 *= corr ;
795
796 return theta0;
797}
◆ ComputeTruePathLengthLimit()
|
virtual |
Reimplemented from G4VMscModel.
Definition at line 421 of file G4UrbanMscModel96.cc.
424{
425 tPathLength = currentMinimalStep;
427
430 couple = track.GetMaterialCutsCouple();
431 SetCurrentCouple(couple);
432 currentMaterialIndex = couple->GetIndex();
433 currentKinEnergy = dp->GetKineticEnergy();
434 currentRange = GetRange(particle,currentKinEnergy,couple);
435 lambda0 = GetTransportMeanFreePath(particle,currentKinEnergy);
436
437 if(tPathLength > currentRange) { tPathLength = currentRange; }
438
439 // stop here if small range particle
440 if(inside || tPathLength < tlimitminfix) {
442 }
443
444 presafety = sp->GetSafety();
445 /*
446 G4cout << "G4Urban96::StepLimit tPathLength= "
447 <<tPathLength<<" safety= " << presafety
448 << " range= " <<currentRange<< " lambda= "<<lambda0
449 << " Alg: " << steppingAlgorithm <<G4endl;
450 */
451 // far from geometry boundary
452 if(currentRange < presafety)
453 {
454 inside = true;
456 }
457
458 // standard version
459 //
461 {
462 //compute geomlimit and presafety
463 geomlimit = ComputeGeomLimit(track, presafety, currentRange);
464
465 // is it far from boundary ?
466 if(currentRange < presafety)
467 {
468 inside = true;
470 }
471
472 smallstep += 1.;
473 insideskin = false;
474
476 {
477 rangeinit = currentRange;
478 if(firstStep) smallstep = 1.e10;
479 else smallstep = 1.;
480
481 //define stepmin here (it depends on lambda!)
482 //rough estimation of lambda_elastic/lambda_transport
483 G4double rat = currentKinEnergy/MeV ;
484 rat = 1.e-3/(rat*(10.+rat)) ;
485 //stepmin ~ lambda_elastic
486 stepmin = rat*lambda0;
487 skindepth = skin*stepmin;
488 //define tlimitmin
489 tlimitmin = 10.*stepmin;
490 if(tlimitmin < tlimitminfix) tlimitmin = tlimitminfix;
491 //G4cout << "rangeinit= " << rangeinit << " stepmin= " << stepmin
492 // << " tlimitmin= " << tlimitmin << " geomlimit= " << geomlimit <<G4endl;
493 // constraint from the geometry
494 if((geomlimit < geombig) && (geomlimit > geommin))
495 {
496 // geomlimit is a geometrical step length
497 // transform it to true path length (estimation)
498 if((1.-geomlimit/lambda0) > 0.)
499 geomlimit = -lambda0*log(1.-geomlimit/lambda0)+tlimitmin ;
500
502 tgeom = geomlimit/facgeom;
503 else
504 tgeom = 2.*geomlimit/facgeom;
505 }
506 else
507 tgeom = geombig;
508 }
509
510
511 //step limit
512 tlimit = facrange*rangeinit;
513
514 //lower limit for tlimit
515 if(tlimit < tlimitmin) tlimit = tlimitmin;
516
517 if(tlimit > tgeom) tlimit = tgeom;
518
519 //G4cout << "tgeom= " << tgeom << " geomlimit= " << geomlimit
520 // << " tlimit= " << tlimit << " presafety= " << presafety << G4endl;
521
522 // shortcut
523 if((tPathLength < tlimit) && (tPathLength < presafety) &&
524 (smallstep >= skin) && (tPathLength < geomlimit-0.999*skindepth))
526
527 // step reduction near to boundary
529 {
530 tlimit = stepmin;
531 insideskin = true;
532 }
533 else if(geomlimit < geombig)
534 {
535 if(geomlimit > skindepth)
536 {
537 if(tlimit > geomlimit-0.999*skindepth)
538 tlimit = geomlimit-0.999*skindepth;
539 }
540 else
541 {
542 insideskin = true;
543 if(tlimit > stepmin) tlimit = stepmin;
544 }
545 }
546
547 if(tlimit < stepmin) tlimit = stepmin;
548
549 // randomize 1st step or 1st 'normal' step in volume
551 {
552 G4double temptlimit = tlimit;
553 if(temptlimit > tlimitmin)
554 {
555 do {
556 temptlimit = G4RandGauss::shoot(tlimit,0.3*tlimit);
557 } while ((temptlimit < tlimitmin) ||
558 (temptlimit > 2.*tlimit-tlimitmin));
559 }
560 else
561 temptlimit = tlimitmin;
562 if(tPathLength > temptlimit) tPathLength = temptlimit;
563 }
564 else
565 {
566 if(tPathLength > tlimit) tPathLength = tlimit ;
567 }
568
569 }
570 // for 'normal' simulation with or without magnetic field
571 // there no small step/single scattering at boundaries
573 {
574 // compute presafety again if presafety <= 0 and no boundary
575 // i.e. when it is needed for optimization purposes
578 /*
579 G4cout << "presafety= " << presafety
580 << " firstStep= " << firstStep
581 << " stepStatus= " << stepStatus
582 << G4endl;
583 */
584 // is far from boundary
585 if(currentRange < presafety)
586 {
587 inside = true;
589 }
590
592 {
593 rangeinit = currentRange;
594 fr = facrange;
595 // 9.1 like stepping for e+/e- only (not for muons,hadrons)
596 if(mass < masslimite)
597 {
598 if(lambda0 > currentRange)
599 rangeinit = lambda0;
600 if(lambda0 > lambdalimit)
601 fr *= 0.75+0.25*lambda0/lambdalimit;
602 }
603
604 //lower limit for tlimit
605 G4double rat = currentKinEnergy/MeV ;
606 rat = 1.e-3/(rat*(10.+rat)) ;
607 tlimitmin = 10.*lambda0*rat;
608 if(tlimitmin < tlimitminfix) tlimitmin = tlimitminfix;
609 }
610 //step limit
611 tlimit = fr*rangeinit;
612
614 tlimit = facsafety*presafety;
615
616 //lower limit for tlimit
617 if(tlimit < tlimitmin) tlimit = tlimitmin;
618
619 if(tPathLength > tlimit) tPathLength = tlimit;
620
621 }
622
623 // version similar to 7.1 (needed for some experiments)
624 else
625 {
627 {
630
631 if(tlimit < tlimitmin) tlimit = tlimitmin;
632 if(tPathLength > tlimit) tPathLength = tlimit;
633 }
634 }
635 //G4cout << "tPathLength= " << tPathLength
636 // << " currentMinimalStep= " << currentMinimalStep << G4endl;
638}
Definition: G4DynamicParticle.hh:74
G4double GetKineticEnergy() const
Definition: G4StepPoint.hh:70
G4StepPoint * GetPreStepPoint() const
const G4DynamicParticle * GetDynamicParticle() const
const G4MaterialCutsCouple * GetMaterialCutsCouple() const
const G4Step * GetStep() const
void SetCurrentCouple(const G4MaterialCutsCouple *)
Definition: G4VEmModel.hh:370
G4double ComputeGeomLimit(const G4Track &, G4double &presafety, G4double limit)
Definition: G4VMscModel.hh:256
G4double GetRange(const G4ParticleDefinition *part, G4double kineticEnergy, const G4MaterialCutsCouple *couple)
Definition: G4VMscModel.hh:288
G4double ComputeSafety(const G4ThreeVector &position, G4double limit)
Definition: G4VMscModel.hh:238
G4double ConvertTrueToGeom(G4double &tLength, G4double &gLength)
Definition: G4VMscModel.hh:246
◆ ComputeTrueStepLength()
Reimplemented from G4VMscModel.
Definition at line 735 of file G4UrbanMscModel96.cc.
736{
737 // step defined other than transportation
738 if(geomStepLength == zPathLength)
739 { return tPathLength; }
740
741 zPathLength = geomStepLength;
742
743 // t = z for very small step
744 if(geomStepLength < tlimitminfix) {
745 tPathLength = geomStepLength;
746
747 // recalculation
748 } else {
749
750 G4double tlength = geomStepLength;
751 if((geomStepLength > lambda0*tausmall) && !insideskin) {
752
753 if(par1 < 0.) {
754 tlength = -lambda0*log(1.-geomStepLength/lambda0) ;
755 } else {
756 if(par1*par3*geomStepLength < 1.) {
757 tlength = (1.-exp(log(1.-par1*par3*geomStepLength)/par3))/par1 ;
758 } else {
759 tlength = currentRange;
760 }
761 }
762 if(tlength < geomStepLength) { tlength = geomStepLength; }
763 else if(tlength > tPathLength) { tlength = tPathLength; }
764 }
765 tPathLength = tlength;
766 }
767 //G4cout << "Urban96::ComputeTrueLength: tPathLength= " << tPathLength
768 // << " step= " << geomStepLength << G4endl;
769 return tPathLength;
770}
◆ Initialise()
|
virtual |
Implements G4VEmModel.
Definition at line 144 of file G4UrbanMscModel96.cc.
146{
147 skindepth = skin*stepmin;
148 // trackID = -1;
149
150 // set values of some data members
151 SetParticle(p);
152
157 << G4endl;
158 }
159
160 fParticleChange = GetParticleChangeForMSC(p);
161
162 //samplez = true;
163 //G4cout << "### G4UrbanMscModel96::Initialise done!" << G4endl;
164}
G4DLLIMPORT std::ostream G4cout
const G4String & GetParticleName() const
Definition: G4ParticleDefinition.hh:115
G4ParticleChangeForMSC * GetParticleChangeForMSC(const G4ParticleDefinition *p=0)
Definition: G4VMscModel.cc:89
◆ SampleScattering()
|
virtual |
Reimplemented from G4VMscModel.
Definition at line 802 of file G4UrbanMscModel96.cc.
804{
806 G4double kineticEnergy = currentKinEnergy;
808 kineticEnergy = GetEnergy(particle,currentRange-tPathLength,couple);
809 } else {
810 kineticEnergy -= tPathLength*GetDEDX(particle,currentKinEnergy,couple);
811 }
812
813 if((kineticEnergy <= 0.0) || (tPathLength <= tlimitminfix) ||
815
816 G4double cth = SampleCosineTheta(tPathLength,kineticEnergy);
817
818 // protection against 'bad' cth values
820
821 // extra protection agaist high energy particles backscattered
822 if(cth < 1.0 - 1000*tPathLength/lambda0 && kineticEnergy > 20*MeV) {
823 //G4cout << "Warning: large scattering E(MeV)= " << kineticEnergy
824 // << " s(mm)= " << tPathLength/mm
825 // << " 1-cosTheta= " << 1.0 - cth << G4endl;
826 // do Gaussian central scattering
827 if(kineticEnergy > GeV && cth < 0.0) {
828 G4ExceptionDescription ed;
830 << " E(MeV)= " << kineticEnergy/MeV
831 << " Step(mm)= " << tPathLength/mm
833 << " CosTheta= " << cth
837 }
838 do {
839 cth = 1.0 + 2*log(G4UniformRand())*tPathLength/lambda0;
840 } while(cth < -1.0);
841 }
842
843 G4double sth = sqrt((1.0 - cth)*(1.0 + cth));
845 G4double dirx = sth*cos(phi);
846 G4double diry = sth*sin(phi);
847
849 G4ThreeVector newDirection(dirx,diry,cth);
850 newDirection.rotateUz(oldDirection);
851 fParticleChange->ProposeMomentumDirection(newDirection);
852 /*
853 G4cout << "G4UrbanMscModel96::SampleSecondaries: e(MeV)= " << kineticEnergy
854 << " sinTheta= " << sth << " safety(mm)= " << safety
855 << " trueStep(mm)= " << tPathLength
856 << " geomStep(mm)= " << zPathLength
857 << G4endl;
858 */
860
861 G4double r = SampleDisplacement();
862 /*
863 G4cout << "G4UrbanMscModel96::SampleSecondaries: e(MeV)= " << kineticEnergy
864 << " sinTheta= " << sth << " r(mm)= " << r
865 << " trueStep(mm)= " << tPathLength
866 << " geomStep(mm)= " << zPathLength
867 << G4endl;
868 */
869 if(r > 0.)
870 {
871 G4double latcorr = LatCorrelation();
872 if(latcorr > r) latcorr = r;
873
874 // sample direction of lateral displacement
875 // compute it from the lateral correlation
876 G4double Phi = 0.;
877 if(std::abs(r*sth) < latcorr)
878 Phi = twopi*G4UniformRand();
879 else
880 {
881 G4double psi = std::acos(latcorr/(r*sth));
883 Phi = phi+psi;
884 else
885 Phi = phi-psi;
886 }
887
888 dirx = std::cos(Phi);
889 diry = std::sin(Phi);
890
893 }
894 }
896}
Definition: ThreeVector.h:41
void set(double x, double y, double z)
const G4ThreeVector & GetMomentumDirection() const
G4ParticleDefinition * GetDefinition() const
const G4Material * GetMaterial() const
Definition: G4MaterialCutsCouple.hh:150
void ProposeMomentumDirection(const G4ThreeVector &Pfinal)
const G4MaterialCutsCouple * CurrentCouple() const
Definition: G4VEmModel.hh:377
G4double GetDEDX(const G4ParticleDefinition *part, G4double kineticEnergy, const G4MaterialCutsCouple *couple)
Definition: G4VMscModel.hh:273
void G4Exception(const char *originOfException, const char *exceptionCode, G4ExceptionSeverity severity, const char *comments)
Definition: G4Exception.cc:41
◆ StartTracking()
|
virtual |
Reimplemented from G4VEmModel.
Definition at line 410 of file G4UrbanMscModel96.cc.
411{
413 firstStep = true;
414 inside = false;
415 insideskin = false;
416 tlimit = geombig;
417}
The documentation for this class was generated from the following files:
