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G4UrbanMscModel95 Class Reference
#include <G4UrbanMscModel95.hh>
Inheritance diagram for G4UrbanMscModel95:
Detailed Description
Definition at line 67 of file G4UrbanMscModel95.hh.
Constructor & Destructor Documentation
◆ G4UrbanMscModel95()
Definition at line 82 of file G4UrbanMscModel95.cc.
83 : G4VMscModel(nam)
84{
85 masslimite = 0.6*MeV;
86 lambdalimit = 1.*mm;
87 fr = 0.02;
88 taubig = 8.0;
89 tausmall = 1.e-16;
90 taulim = 1.e-6;
91 currentTau = taulim;
92 tlimitminfix = 1.e-6*mm;
93 stepmin = tlimitminfix;
94 smallstep = 1.e10;
95 currentRange = 0. ;
96 rangeinit = 0.;
97 tlimit = 1.e10*mm;
98 tlimitmin = 10.*tlimitminfix;
99 tgeom = 1.e50*mm;
100 geombig = 1.e50*mm;
101 geommin = 1.e-3*mm;
102 geomlimit = geombig;
103 presafety = 0.*mm;
104 //facsafety = 0.50 ;
105
106 y = 0.;
107
108 Zold = 0.;
109 Zeff = 1.;
110 Z2 = 1.;
111 Z23 = 1.;
112 lnZ = 0.;
113 coeffth1 = 0.;
114 coeffth2 = 0.;
115 coeffc1 = 0.;
116 coeffc2 = 0.;
117 coeffc3 = 0.;
118 coeffc4 = 0.;
119 scr1ini = fine_structure_const*fine_structure_const*
120 electron_mass_c2*electron_mass_c2/(0.885*0.885*4.*pi);
121 scr2ini = 3.76*fine_structure_const*fine_structure_const;
122 scr1 = 0.;
123 scr2 = 0.;
124
125 theta0max = pi/6.;
126 rellossmax = 0.50;
127 third = 1./3.;
128 particle = 0;
129 theManager = G4LossTableManager::Instance();
130 firstStep = true;
131 inside = false;
132 insideskin = false;
133
134 skindepth = skin*stepmin;
135
136 mass = proton_mass_c2;
137 charge = ChargeSquare = 1.0;
138 currentKinEnergy = currentRadLength = lambda0 = lambdaeff = tPathLength
139 = zPathLength = par1 = par2 = par3 = 0;
140
141 currentMaterialIndex = -1;
142 fParticleChange = 0;
143 couple = 0;
145}
static G4LossTableManager * Instance()
Definition: G4LossTableManager.cc:107
Definition: G4VMscModel.hh:69
◆ ~G4UrbanMscModel95()
|
virtual |
Definition at line 149 of file G4UrbanMscModel95.cc.
150{}
Member Function Documentation
◆ ComputeCrossSectionPerAtom()
|
virtual |
Reimplemented from G4VEmModel.
Definition at line 178 of file G4UrbanMscModel95.cc.
183{
186 Bohr_radius*Bohr_radius/(hbarc*hbarc);
188
190 50., 56., 64., 74., 79., 82. };
191
193 1*keV, 2*keV, 4*keV, 7*keV,
194 10*keV, 20*keV, 40*keV, 70*keV,
195 100*keV, 200*keV, 400*keV, 700*keV,
196 1*MeV, 2*MeV, 4*MeV, 7*MeV,
197 10*MeV, 20*MeV};
198
199 // corr. factors for e-/e+ lambda for T <= Tlim
200 G4double celectron[15][22] =
201 {{1.125,1.072,1.051,1.047,1.047,1.050,1.052,1.054,
202 1.054,1.057,1.062,1.069,1.075,1.090,1.105,1.111,
203 1.112,1.108,1.100,1.093,1.089,1.087 },
204 {1.408,1.246,1.143,1.096,1.077,1.059,1.053,1.051,
205 1.052,1.053,1.058,1.065,1.072,1.087,1.101,1.108,
206 1.109,1.105,1.097,1.090,1.086,1.082 },
207 {2.833,2.268,1.861,1.612,1.486,1.309,1.204,1.156,
208 1.136,1.114,1.106,1.106,1.109,1.119,1.129,1.132,
209 1.131,1.124,1.113,1.104,1.099,1.098 },
210 {3.879,3.016,2.380,2.007,1.818,1.535,1.340,1.236,
211 1.190,1.133,1.107,1.099,1.098,1.103,1.110,1.113,
212 1.112,1.105,1.096,1.089,1.085,1.098 },
213 {6.937,4.330,2.886,2.256,1.987,1.628,1.395,1.265,
214 1.203,1.122,1.080,1.065,1.061,1.063,1.070,1.073,
215 1.073,1.070,1.064,1.059,1.056,1.056 },
216 {9.616,5.708,3.424,2.551,2.204,1.762,1.485,1.330,
217 1.256,1.155,1.099,1.077,1.070,1.068,1.072,1.074,
218 1.074,1.070,1.063,1.059,1.056,1.052 },
219 {11.72,6.364,3.811,2.806,2.401,1.884,1.564,1.386,
220 1.300,1.180,1.112,1.082,1.073,1.066,1.068,1.069,
221 1.068,1.064,1.059,1.054,1.051,1.050 },
222 {18.08,8.601,4.569,3.183,2.662,2.025,1.646,1.439,
223 1.339,1.195,1.108,1.068,1.053,1.040,1.039,1.039,
224 1.039,1.037,1.034,1.031,1.030,1.036 },
225 {18.22,10.48,5.333,3.713,3.115,2.367,1.898,1.631,
226 1.498,1.301,1.171,1.105,1.077,1.048,1.036,1.033,
227 1.031,1.028,1.024,1.022,1.021,1.024 },
228 {14.14,10.65,5.710,3.929,3.266,2.453,1.951,1.669,
229 1.528,1.319,1.178,1.106,1.075,1.040,1.027,1.022,
230 1.020,1.017,1.015,1.013,1.013,1.020 },
231 {14.11,11.73,6.312,4.240,3.478,2.566,2.022,1.720,
232 1.569,1.342,1.186,1.102,1.065,1.022,1.003,0.997,
233 0.995,0.993,0.993,0.993,0.993,1.011 },
234 {22.76,20.01,8.835,5.287,4.144,2.901,2.219,1.855,
235 1.677,1.410,1.224,1.121,1.073,1.014,0.986,0.976,
236 0.974,0.972,0.973,0.974,0.975,0.987 },
237 {50.77,40.85,14.13,7.184,5.284,3.435,2.520,2.059,
238 1.837,1.512,1.283,1.153,1.091,1.010,0.969,0.954,
239 0.950,0.947,0.949,0.952,0.954,0.963 },
240 {65.87,59.06,15.87,7.570,5.567,3.650,2.682,2.182,
241 1.939,1.579,1.325,1.178,1.108,1.014,0.965,0.947,
242 0.941,0.938,0.940,0.944,0.946,0.954 },
243 {55.60,47.34,15.92,7.810,5.755,3.767,2.760,2.239,
244 1.985,1.609,1.343,1.188,1.113,1.013,0.960,0.939,
245 0.933,0.930,0.933,0.936,0.939,0.949 }};
246
247 G4double cpositron[15][22] = {
248 {2.589,2.044,1.658,1.446,1.347,1.217,1.144,1.110,
249 1.097,1.083,1.080,1.086,1.092,1.108,1.123,1.131,
250 1.131,1.126,1.117,1.108,1.103,1.100 },
251 {3.904,2.794,2.079,1.710,1.543,1.325,1.202,1.145,
252 1.122,1.096,1.089,1.092,1.098,1.114,1.130,1.137,
253 1.138,1.132,1.122,1.113,1.108,1.102 },
254 {7.970,6.080,4.442,3.398,2.872,2.127,1.672,1.451,
255 1.357,1.246,1.194,1.179,1.178,1.188,1.201,1.205,
256 1.203,1.190,1.173,1.159,1.151,1.145 },
257 {9.714,7.607,5.747,4.493,3.815,2.777,2.079,1.715,
258 1.553,1.353,1.253,1.219,1.211,1.214,1.225,1.228,
259 1.225,1.210,1.191,1.175,1.166,1.174 },
260 {17.97,12.95,8.628,6.065,4.849,3.222,2.275,1.820,
261 1.624,1.382,1.259,1.214,1.202,1.202,1.214,1.219,
262 1.217,1.203,1.184,1.169,1.160,1.151 },
263 {24.83,17.06,10.84,7.355,5.767,3.707,2.546,1.996,
264 1.759,1.465,1.311,1.252,1.234,1.228,1.238,1.241,
265 1.237,1.222,1.201,1.184,1.174,1.159 },
266 {23.26,17.15,11.52,8.049,6.375,4.114,2.792,2.155,
267 1.880,1.535,1.353,1.281,1.258,1.247,1.254,1.256,
268 1.252,1.234,1.212,1.194,1.183,1.170 },
269 {22.33,18.01,12.86,9.212,7.336,4.702,3.117,2.348,
270 2.015,1.602,1.385,1.297,1.268,1.251,1.256,1.258,
271 1.254,1.237,1.214,1.195,1.185,1.179 },
272 {33.91,24.13,15.71,10.80,8.507,5.467,3.692,2.808,
273 2.407,1.873,1.564,1.425,1.374,1.330,1.324,1.320,
274 1.312,1.288,1.258,1.235,1.221,1.205 },
275 {32.14,24.11,16.30,11.40,9.015,5.782,3.868,2.917,
276 2.490,1.925,1.596,1.447,1.391,1.342,1.332,1.327,
277 1.320,1.294,1.264,1.240,1.226,1.214 },
278 {29.51,24.07,17.19,12.28,9.766,6.238,4.112,3.066,
279 2.602,1.995,1.641,1.477,1.414,1.356,1.342,1.336,
280 1.328,1.302,1.270,1.245,1.231,1.233 },
281 {38.19,30.85,21.76,15.35,12.07,7.521,4.812,3.498,
282 2.926,2.188,1.763,1.563,1.484,1.405,1.382,1.371,
283 1.361,1.330,1.294,1.267,1.251,1.239 },
284 {49.71,39.80,27.96,19.63,15.36,9.407,5.863,4.155,
285 3.417,2.478,1.944,1.692,1.589,1.480,1.441,1.423,
286 1.409,1.372,1.330,1.298,1.280,1.258 },
287 {59.25,45.08,30.36,20.83,16.15,9.834,6.166,4.407,
288 3.641,2.648,2.064,1.779,1.661,1.531,1.482,1.459,
289 1.442,1.400,1.354,1.319,1.299,1.272 },
290 {56.38,44.29,30.50,21.18,16.51,10.11,6.354,4.542,
291 3.752,2.724,2.116,1.817,1.692,1.554,1.499,1.474,
292 1.456,1.412,1.364,1.328,1.307,1.282 }};
293
294 //data/corrections for T > Tlim
295 G4double Tlim = 10.*MeV;
296 G4double beta2lim = Tlim*(Tlim+2.*electron_mass_c2)/
297 ((Tlim+electron_mass_c2)*(Tlim+electron_mass_c2));
298 G4double bg2lim = Tlim*(Tlim+2.*electron_mass_c2)/
299 (electron_mass_c2*electron_mass_c2);
300
301 G4double sig0[15] = {0.2672*barn, 0.5922*barn, 2.653*barn, 6.235*barn,
302 11.69*barn , 13.24*barn , 16.12*barn, 23.00*barn ,
303 35.13*barn , 39.95*barn , 50.85*barn, 67.19*barn ,
304 91.15*barn , 104.4*barn , 113.1*barn};
305
306 G4double hecorr[15] = {120.70, 117.50, 105.00, 92.92, 79.23, 74.510, 68.29,
307 57.39, 41.97, 36.14, 24.53, 10.21, -7.855, -16.84,
308 -22.30};
309
310 G4double sigma;
311 SetParticle(part);
312
313 Z23 = pow(AtomicNumber,2./3.);
314
315 // correction if particle .ne. e-/e+
316 // compute equivalent kinetic energy
317 // lambda depends on p*beta ....
318
319 G4double eKineticEnergy = KineticEnergy;
320
321 if(mass > electron_mass_c2)
322 {
323 G4double TAU = KineticEnergy/mass ;
324 G4double c = mass*TAU*(TAU+2.)/(electron_mass_c2*(TAU+1.)) ;
325 G4double w = c-2. ;
326 G4double tau = 0.5*(w+sqrt(w*w+4.*c)) ;
327 eKineticEnergy = electron_mass_c2*tau ;
328 }
329
330 G4double eTotalEnergy = eKineticEnergy + electron_mass_c2 ;
331 G4double beta2 = eKineticEnergy*(eTotalEnergy+electron_mass_c2)
332 /(eTotalEnergy*eTotalEnergy);
333 G4double bg2 = eKineticEnergy*(eTotalEnergy+electron_mass_c2)
334 /(electron_mass_c2*electron_mass_c2);
335
336 G4double eps = epsfactor*bg2/Z23;
337
338 if (eps<epsmin) sigma = 2.*eps*eps;
339 else if(eps<epsmax) sigma = log(1.+2.*eps)-2.*eps/(1.+2.*eps);
340 else sigma = log(2.*eps)-1.+1./eps;
341
342 sigma *= ChargeSquare*AtomicNumber*AtomicNumber/(beta2*bg2);
343
344 // interpolate in AtomicNumber and beta2
345 G4double c1,c2,cc1,cc2,corr;
346
347 // get bin number in Z
348 G4int iZ = 14;
349 while ((iZ>=0)&&(Zdat[iZ]>=AtomicNumber)) iZ -= 1;
350 if (iZ==14) iZ = 13;
351 if (iZ==-1) iZ = 0 ;
352
353 G4double ZZ1 = Zdat[iZ];
354 G4double ZZ2 = Zdat[iZ+1];
355 G4double ratZ = (AtomicNumber-ZZ1)*(AtomicNumber+ZZ1)/
356 ((ZZ2-ZZ1)*(ZZ2+ZZ1));
357
358 if(eKineticEnergy <= Tlim)
359 {
360 // get bin number in T (beta2)
361 G4int iT = 21;
362 while ((iT>=0)&&(Tdat[iT]>=eKineticEnergy)) iT -= 1;
363 if(iT==21) iT = 20;
364 if(iT==-1) iT = 0 ;
365
366 // calculate betasquare values
367 G4double T = Tdat[iT], E = T + electron_mass_c2;
368 G4double b2small = T*(E+electron_mass_c2)/(E*E);
369
370 T = Tdat[iT+1]; E = T + electron_mass_c2;
371 G4double b2big = T*(E+electron_mass_c2)/(E*E);
372 G4double ratb2 = (beta2-b2small)/(b2big-b2small);
373
374 if (charge < 0.)
375 {
376 c1 = celectron[iZ][iT];
377 c2 = celectron[iZ+1][iT];
378 cc1 = c1+ratZ*(c2-c1);
379
380 c1 = celectron[iZ][iT+1];
381 c2 = celectron[iZ+1][iT+1];
382 cc2 = c1+ratZ*(c2-c1);
383
384 corr = cc1+ratb2*(cc2-cc1);
385
386 sigma *= sigmafactor/corr;
387 }
388 else
389 {
390 c1 = cpositron[iZ][iT];
391 c2 = cpositron[iZ+1][iT];
392 cc1 = c1+ratZ*(c2-c1);
393
394 c1 = cpositron[iZ][iT+1];
395 c2 = cpositron[iZ+1][iT+1];
396 cc2 = c1+ratZ*(c2-c1);
397
398 corr = cc1+ratb2*(cc2-cc1);
399
400 sigma *= sigmafactor/corr;
401 }
402 }
403 else
404 {
405 c1 = bg2lim*sig0[iZ]*(1.+hecorr[iZ]*(beta2-beta2lim))/bg2;
406 c2 = bg2lim*sig0[iZ+1]*(1.+hecorr[iZ+1]*(beta2-beta2lim))/bg2;
407 if((AtomicNumber >= ZZ1) && (AtomicNumber <= ZZ2))
408 sigma = c1+ratZ*(c2-c1) ;
409 else if(AtomicNumber < ZZ1)
410 sigma = AtomicNumber*AtomicNumber*c1/(ZZ1*ZZ1);
411 else if(AtomicNumber > ZZ2)
412 sigma = AtomicNumber*AtomicNumber*c2/(ZZ2*ZZ2);
413 }
414 return sigma;
415
416}
◆ ComputeGeomPathLength()
Reimplemented from G4VMscModel.
Definition at line 651 of file G4UrbanMscModel95.cc.
652{
653 firstStep = false;
654 lambdaeff = lambda0;
655 par1 = -1. ;
656 par2 = par3 = 0. ;
657
658 // do the true -> geom transformation
659 zPathLength = tPathLength;
660
661 // z = t for very small tPathLength
662 if(tPathLength < tlimitminfix) return zPathLength;
663
664 // this correction needed to run MSC with eIoni and eBrem inactivated
665 // and makes no harm for a normal run
666 // It is already checked
667 // if(tPathLength > currentRange)
668 // tPathLength = currentRange ;
669
670 G4double tau = tPathLength/lambda0 ;
671
672 if ((tau <= tausmall) || insideskin) {
673 zPathLength = tPathLength;
674 if(zPathLength > lambda0) zPathLength = lambda0;
675 return zPathLength;
676 }
677
678 G4double zmean = tPathLength;
680 if(tau < taulim) zmean = tPathLength*(1.-0.5*tau) ;
681 else zmean = lambda0*(1.-exp(-tau));
682 zPathLength = zmean ;
683 return zPathLength;
684
685 } else if(currentKinEnergy < mass || tPathLength == currentRange) {
686 par1 = 1./currentRange ;
687 par2 = 1./(par1*lambda0) ;
688 par3 = 1.+par2 ;
689 if(tPathLength < currentRange)
690 zmean = (1.-exp(par3*log(1.-tPathLength/currentRange)))/(par1*par3) ;
691 else {
692 zmean = 1./(par1*par3) ;
693 }
694 zPathLength = zmean ;
695 return zPathLength;
696
697 } else {
700
701 par1 = (lambda0-lambda1)/(lambda0*tPathLength);
702 par2 = 1./(par1*lambda0);
703 par3 = 1.+par2 ;
704 zmean = (1.-exp(par3*log(lambda1/lambda0)))/(par1*par3);
705 }
706
707 zPathLength = zmean;
708
709 // sample z
711 {
713 G4double zt = zmean/tPathLength ;
714
715 if (tPathLength > stepmin && zt < ztmax)
716 {
717 G4double u,cz1;
718 if(zt >= third)
719 {
720 G4double cz = 0.5*(3.*zt-1.)/(1.-zt) ;
721 cz1 = 1.+cz ;
722 G4double u0 = cz/cz1 ;
723 G4double grej ;
724 do {
725 u = exp(log(G4UniformRand())/cz1) ;
726 grej = exp(cz*log(u/u0))*(1.-u)/(1.-u0) ;
728 }
729 else
730 {
731 u = 2.*zt*G4UniformRand();
732 }
733 zPathLength = tPathLength*u ;
734 }
735 }
736
737 if(zPathLength > lambda0) { zPathLength = lambda0; }
738 //G4cout<< "zPathLength= "<< zPathLength<< " lambda1= " << lambda0 << G4endl;
739 return zPathLength;
740}
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 784 of file G4UrbanMscModel95.cc.
786{
787 // for all particles take the width of the central part
788 // from a parametrization similar to the Highland formula
789 // ( Highland formula: Particle Physics Booklet, July 2002, eq. 26.10)
791 G4double betacp = sqrt(currentKinEnergy*(currentKinEnergy+2.*mass)*
792 KineticEnergy*(KineticEnergy+2.*mass)/
793 ((currentKinEnergy+mass)*(KineticEnergy+mass)));
794 y = trueStepLength/currentRadLength;
795 G4double theta0 = c_highland*std::abs(charge)*sqrt(y)/betacp;
796 y = log(y);
797 // correction factor from e- scattering data
798 G4double corr = coeffth1+coeffth2*y;
799
800 theta0 *= corr ;
801
802 return theta0;
803}
◆ ComputeTruePathLengthLimit()
|
virtual |
Reimplemented from G4VMscModel.
Definition at line 431 of file G4UrbanMscModel95.cc.
434{
435 tPathLength = currentMinimalStep;
437
440 couple = track.GetMaterialCutsCouple();
441 SetCurrentCouple(couple);
442 currentMaterialIndex = couple->GetIndex();
443 currentKinEnergy = dp->GetKineticEnergy();
444 currentRange = GetRange(particle,currentKinEnergy,couple);
445 lambda0 = GetTransportMeanFreePath(particle,currentKinEnergy);
446 if(tPathLength > currentRange) { tPathLength = currentRange; }
447
448 // stop here if small range particle
449 if(inside || tPathLength < tlimitminfix) {
451 }
452
453 presafety = sp->GetSafety();
454 /*
455 G4cout << "G4Urban95::StepLimit tPathLength= "
456 <<tPathLength<<" safety= " << presafety
457 << " range= " <<currentRange<< " lambda= "<<lambda0
458 << " Alg: " << steppingAlgorithm <<G4endl;
459 */
460 // far from geometry boundary
461 if(currentRange < presafety)
462 {
463 inside = true;
465 }
466
467 // standard version
468 //
470 {
471 //compute geomlimit and presafety
472 geomlimit = ComputeGeomLimit(track, presafety, currentRange);
473
474 // is it far from boundary ?
475 if(currentRange < presafety)
476 {
477 inside = true;
479 }
480
481 smallstep += 1.;
482 insideskin = false;
483
485 {
486 rangeinit = currentRange;
487 if(firstStep) smallstep = 1.e10;
488 else smallstep = 1.;
489
490 //define stepmin here (it depends on lambda!)
491 //rough estimation of lambda_elastic/lambda_transport
492 G4double rat = currentKinEnergy/MeV ;
493 rat = 1.e-3/(rat*(10.+rat)) ;
494 //stepmin ~ lambda_elastic
495 stepmin = rat*lambda0;
496 skindepth = skin*stepmin;
497 //define tlimitmin
498 tlimitmin = 10.*stepmin;
499 if(tlimitmin < tlimitminfix) tlimitmin = tlimitminfix;
500 //G4cout << "rangeinit= " << rangeinit << " stepmin= " << stepmin
501 // << " tlimitmin= " << tlimitmin << " geomlimit= " << geomlimit <<G4endl;
502 // constraint from the geometry
503 if((geomlimit < geombig) && (geomlimit > geommin))
504 {
505 // geomlimit is a geometrical step length
506 // transform it to true path length (estimation)
507 if((1.-geomlimit/lambda0) > 0.)
508 geomlimit = -lambda0*log(1.-geomlimit/lambda0)+tlimitmin ;
509
511 tgeom = geomlimit/facgeom;
512 else
513 tgeom = 2.*geomlimit/facgeom;
514 }
515 else
516 tgeom = geombig;
517 }
518
519
520 //step limit
521 tlimit = facrange*rangeinit;
522
523 //lower limit for tlimit
524 if(tlimit < tlimitmin) tlimit = tlimitmin;
525
526 if(tlimit > tgeom) tlimit = tgeom;
527
528 //G4cout << "tgeom= " << tgeom << " geomlimit= " << geomlimit
529 // << " tlimit= " << tlimit << " presafety= " << presafety << G4endl;
530
531 // shortcut
532 if((tPathLength < tlimit) && (tPathLength < presafety) &&
533 (smallstep >= skin) && (tPathLength < geomlimit-0.999*skindepth))
535
536 // step reduction near to boundary
538 {
539 tlimit = stepmin;
540 insideskin = true;
541 }
542 else if(geomlimit < geombig)
543 {
544 if(geomlimit > skindepth)
545 {
546 if(tlimit > geomlimit-0.999*skindepth)
547 tlimit = geomlimit-0.999*skindepth;
548 }
549 else
550 {
551 insideskin = true;
552 if(tlimit > stepmin) tlimit = stepmin;
553 }
554 }
555
556 if(tlimit < stepmin) tlimit = stepmin;
557
558 // randomize 1st step or 1st 'normal' step in volume
560 {
561 G4double temptlimit = tlimit;
562 if(temptlimit > tlimitmin)
563 {
564 do {
565 temptlimit = G4RandGauss::shoot(tlimit,0.3*tlimit);
566 } while ((temptlimit < tlimitmin) ||
567 (temptlimit > 2.*tlimit-tlimitmin));
568 }
569 else
570 temptlimit = tlimitmin;
571 if(tPathLength > temptlimit) tPathLength = temptlimit;
572 }
573 else
574 {
575 if(tPathLength > tlimit) tPathLength = tlimit ;
576 }
577
578 }
579 // for 'normal' simulation with or without magnetic field
580 // there no small step/single scattering at boundaries
582 {
583 // compute presafety again if presafety <= 0 and no boundary
584 // i.e. when it is needed for optimization purposes
587 /*
588 G4cout << "presafety= " << presafety
589 << " firstStep= " << firstStep
590 << " stepStatus= " << stepStatus
591 << G4endl;
592 */
593 // is far from boundary
594 if(currentRange < presafety)
595 {
596 inside = true;
598 }
599
601 {
602 rangeinit = currentRange;
603 fr = facrange;
604 // 9.1 like stepping for e+/e- only (not for muons,hadrons)
605 if(mass < masslimite)
606 {
607 if(lambda0 > currentRange)
608 rangeinit = lambda0;
609 if(lambda0 > lambdalimit)
610 fr *= 0.75+0.25*lambda0/lambdalimit;
611 }
612
613 //lower limit for tlimit
614 G4double rat = currentKinEnergy/MeV ;
615 rat = 1.e-3/(rat*(10.+rat)) ;
616 tlimitmin = 10.*lambda0*rat;
617 if(tlimitmin < tlimitminfix) tlimitmin = tlimitminfix;
618 }
619 //step limit
620 tlimit = fr*rangeinit;
621
623 tlimit = facsafety*presafety;
624
625 //lower limit for tlimit
626 if(tlimit < tlimitmin) tlimit = tlimitmin;
627
628 if(tPathLength > tlimit) tPathLength = tlimit;
629
630 }
631
632 // version similar to 7.1 (needed for some experiments)
633 else
634 {
636 {
639
640 if(tlimit < tlimitmin) tlimit = tlimitmin;
641 if(tPathLength > tlimit) tPathLength = tlimit;
642 }
643 }
644 //G4cout << "tPathLength= " << tPathLength
645 // << " currentMinimalStep= " << currentMinimalStep << G4endl;
647}
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 744 of file G4UrbanMscModel95.cc.
745{
746 // step defined other than transportation
747 if(geomStepLength == zPathLength)
748 { return tPathLength; }
749
750 zPathLength = geomStepLength;
751
752 // t = z for very small step
753 if(geomStepLength < tlimitminfix) {
754 tPathLength = geomStepLength;
755
756 // recalculation
757 } else {
758
759 G4double tlength = geomStepLength;
760 if((geomStepLength > lambda0*tausmall) && !insideskin) {
761
762 if(par1 < 0.) {
763 tlength = -lambda0*log(1.-geomStepLength/lambda0) ;
764 } else {
765 if(par1*par3*geomStepLength < 1.) {
766 tlength = (1.-exp(log(1.-par1*par3*geomStepLength)/par3))/par1 ;
767 } else {
768 tlength = currentRange;
769 }
770 }
771 if(tlength < geomStepLength) { tlength = geomStepLength; }
772 else if(tlength > tPathLength) { tlength = tPathLength; }
773 }
774 tPathLength = tlength;
775 }
776 //G4cout << "Urban95::ComputeTrueLength: tPathLength= " << tPathLength
777 // << " step= " << geomStepLength << G4endl;
778
779 return tPathLength;
780}
◆ Initialise()
|
virtual |
Implements G4VEmModel.
Definition at line 154 of file G4UrbanMscModel95.cc.
156{
157 skindepth = skin*stepmin;
158 // trackID = -1;
159
160 // set values of some data members
161 SetParticle(p);
162 /*
163 if(p->GetPDGMass() > MeV) {
164 G4cout << "### WARNING: G4UrbanMscModel95 model is used for "
165 << p->GetParticleName() << " !!! " << G4endl;
166 G4cout << "### This model should be used only for e+-"
167 << G4endl;
168 }
169 */
170 fParticleChange = GetParticleChangeForMSC(p);
171
172 //samplez = true;
173 //G4cout << "### G4UrbanMscModel95::Initialise done!" << G4endl;
174}
G4ParticleChangeForMSC * GetParticleChangeForMSC(const G4ParticleDefinition *p=0)
Definition: G4VMscModel.cc:89
◆ SampleScattering()
|
virtual |
Reimplemented from G4VMscModel.
Definition at line 808 of file G4UrbanMscModel95.cc.
810{
812 G4double kineticEnergy = currentKinEnergy;
814 kineticEnergy = GetEnergy(particle,currentRange-tPathLength,couple);
815 } else {
816 kineticEnergy -= tPathLength*GetDEDX(particle,currentKinEnergy,couple);
817 }
818
819 if((kineticEnergy <= eV) || (tPathLength <= tlimitminfix) ||
821
822 G4double cth = SampleCosineTheta(tPathLength,kineticEnergy);
823
824 // protection against 'bad' cth values
826
827 // extra protection agaist high energy particles backscattered
828 if(cth < 1.0 - 1000*tPathLength/lambda0 && kineticEnergy > 20*MeV) {
829 //G4cout << "Warning: large scattering E(MeV)= " << kineticEnergy
830 // << " s(mm)= " << tPathLength/mm
831 // << " 1-cosTheta= " << 1.0 - cth << G4endl;
832 // do Gaussian central scattering
833 if(kineticEnergy > GeV && cth < 0.0) {
834 G4ExceptionDescription ed;
836 << " E(MeV)= " << kineticEnergy/MeV
837 << " Step(mm)= " << tPathLength/mm
839 << " CosTheta= " << cth
843 }
844 do {
845 cth = 1.0 + 2*log(G4UniformRand())*tPathLength/lambda0;
846 } while(cth < -1.0);
847 }
848
849 G4double sth = sqrt((1.0 - cth)*(1.0 + cth));
851 G4double dirx = sth*cos(phi);
852 G4double diry = sth*sin(phi);
853
855 G4ThreeVector newDirection(dirx,diry,cth);
856 newDirection.rotateUz(oldDirection);
857 fParticleChange->ProposeMomentumDirection(newDirection);
858 /*
859 G4cout << "G4UrbanMscModel95::SampleSecondaries: e(MeV)= " << kineticEnergy
860 << " sinTheta= " << sth << " safety(mm)= " << safety
861 << " trueStep(mm)= " << tPathLength
862 << " geomStep(mm)= " << zPathLength
863 << G4endl;
864 */
866
867 G4double r = SampleDisplacement();
868 /*
869 G4cout << "G4UrbanMscModel95::SampleSecondaries: e(MeV)= " << kineticEnergy
870 << " sinTheta= " << sth << " r(mm)= " << r
871 << " trueStep(mm)= " << tPathLength
872 << " geomStep(mm)= " << zPathLength
873 << G4endl;
874 */
875 if(r > 0.)
876 {
877 G4double latcorr = LatCorrelation();
878 if(latcorr > r) latcorr = r;
879
880 // sample direction of lateral displacement
881 // compute it from the lateral correlation
882 G4double Phi = 0.;
883 if(std::abs(r*sth) < latcorr)
884 Phi = twopi*G4UniformRand();
885 else
886 {
887 G4double psi = std::acos(latcorr/(r*sth));
889 Phi = phi+psi;
890 else
891 Phi = phi-psi;
892 }
893
894 dirx = std::cos(Phi);
895 diry = std::sin(Phi);
896
899 }
900 }
902}
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 G4String & GetParticleName() const
Definition: G4ParticleDefinition.hh:115
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 420 of file G4UrbanMscModel95.cc.
421{
423 firstStep = true;
424 inside = false;
425 insideskin = false;
426 tlimit = geombig;
427}
The documentation for this class was generated from the following files:
