#include <G4UrbanMscModel96.hh>
Inheritance diagram for G4UrbanMscModel96:
Public Member Functions | |
G4UrbanMscModel96 (const G4String &nam="UrbanMsc96") | |
virtual | ~G4UrbanMscModel96 () |
void | Initialise (const G4ParticleDefinition *, const G4DataVector &) |
void | StartTracking (G4Track *) |
G4double | ComputeCrossSectionPerAtom (const G4ParticleDefinition *particle, G4double KineticEnergy, G4double AtomicNumber, G4double AtomicWeight=0., G4double cut=0., G4double emax=DBL_MAX) |
G4ThreeVector & | SampleScattering (const G4ThreeVector &, G4double safety) |
G4double | ComputeTruePathLengthLimit (const G4Track &track, G4double ¤tMinimalStep) |
G4double | ComputeGeomPathLength (G4double truePathLength) |
G4double | ComputeTrueStepLength (G4double geomStepLength) |
G4double | ComputeTheta0 (G4double truePathLength, G4double KineticEnergy) |
Definition at line 70 of file G4UrbanMscModel96.hh.
G4UrbanMscModel96::G4UrbanMscModel96 | ( | const G4String & | nam = "UrbanMsc96" |
) |
Definition at line 75 of file G4UrbanMscModel96.cc.
References G4LossTableManager::Instance(), G4INCL::Math::pi, G4VMscModel::SetSampleZ(), and G4VMscModel::skin.
00076 : G4VMscModel(nam) 00077 { 00078 masslimite = 0.6*MeV; 00079 lambdalimit = 1.*mm; 00080 fr = 0.02; 00081 taubig = 8.0; 00082 tausmall = 1.e-16; 00083 taulim = 1.e-6; 00084 currentTau = taulim; 00085 tlimitminfix = 1.e-6*mm; 00086 stepmin = tlimitminfix; 00087 smallstep = 1.e10; 00088 currentRange = 0. ; 00089 rangeinit = 0.; 00090 tlimit = 1.e10*mm; 00091 tlimitmin = 10.*tlimitminfix; 00092 tgeom = 1.e50*mm; 00093 geombig = 1.e50*mm; 00094 geommin = 1.e-3*mm; 00095 geomlimit = geombig; 00096 presafety = 0.*mm; 00097 //facsafety = 0.50 ; 00098 00099 y = 0.; 00100 00101 Zold = 0.; 00102 Zeff = 1.; 00103 Z2 = 1.; 00104 Z23 = 1.; 00105 lnZ = 0.; 00106 coeffth1 = 0.; 00107 coeffth2 = 0.; 00108 coeffc1 = 0.; 00109 coeffc2 = 0.; 00110 coeffc3 = 0.; 00111 coeffc4 = 0.; 00112 00113 theta0max = pi/6.; 00114 rellossmax = 0.50; 00115 third = 1./3.; 00116 particle = 0; 00117 theManager = G4LossTableManager::Instance(); 00118 firstStep = true; 00119 inside = false; 00120 insideskin = false; 00121 00122 skindepth = skin*stepmin; 00123 00124 mass = proton_mass_c2; 00125 charge = ChargeSquare = 1.0; 00126 currentKinEnergy = currentRadLength = lambda0 = lambdaeff = tPathLength 00127 = zPathLength = par1 = par2 = par3 = 0; 00128 00129 currentMaterialIndex = -1; 00130 fParticleChange = 0; 00131 couple = 0; 00132 SetSampleZ(false); 00133 }
G4UrbanMscModel96::~G4UrbanMscModel96 | ( | ) | [virtual] |
G4double G4UrbanMscModel96::ComputeCrossSectionPerAtom | ( | const G4ParticleDefinition * | particle, | |
G4double | KineticEnergy, | |||
G4double | AtomicNumber, | |||
G4double | AtomicWeight = 0. , |
|||
G4double | cut = 0. , |
|||
G4double | emax = DBL_MAX | |||
) | [virtual] |
Reimplemented from G4VEmModel.
Definition at line 166 of file G4UrbanMscModel96.cc.
References G4lrint(), G4Pow::GetInstance(), and G4Pow::Z23().
00171 { 00172 static const G4double sigmafactor = 00173 twopi*classic_electr_radius*classic_electr_radius; 00174 static const G4double epsfactor = 2.*electron_mass_c2*electron_mass_c2* 00175 Bohr_radius*Bohr_radius/(hbarc*hbarc); 00176 static const G4double epsmin = 1.e-4 , epsmax = 1.e10; 00177 00178 static const G4double Zdat[15] = { 4., 6., 13., 20., 26., 29., 32., 38., 47., 00179 50., 56., 64., 74., 79., 82. }; 00180 00181 static const G4double Tdat[22] = { 100*eV, 200*eV, 400*eV, 700*eV, 00182 1*keV, 2*keV, 4*keV, 7*keV, 00183 10*keV, 20*keV, 40*keV, 70*keV, 00184 100*keV, 200*keV, 400*keV, 700*keV, 00185 1*MeV, 2*MeV, 4*MeV, 7*MeV, 00186 10*MeV, 20*MeV}; 00187 00188 // corr. factors for e-/e+ lambda for T <= Tlim 00189 static const G4double celectron[15][22] = 00190 {{1.125,1.072,1.051,1.047,1.047,1.050,1.052,1.054, 00191 1.054,1.057,1.062,1.069,1.075,1.090,1.105,1.111, 00192 1.112,1.108,1.100,1.093,1.089,1.087 }, 00193 {1.408,1.246,1.143,1.096,1.077,1.059,1.053,1.051, 00194 1.052,1.053,1.058,1.065,1.072,1.087,1.101,1.108, 00195 1.109,1.105,1.097,1.090,1.086,1.082 }, 00196 {2.833,2.268,1.861,1.612,1.486,1.309,1.204,1.156, 00197 1.136,1.114,1.106,1.106,1.109,1.119,1.129,1.132, 00198 1.131,1.124,1.113,1.104,1.099,1.098 }, 00199 {3.879,3.016,2.380,2.007,1.818,1.535,1.340,1.236, 00200 1.190,1.133,1.107,1.099,1.098,1.103,1.110,1.113, 00201 1.112,1.105,1.096,1.089,1.085,1.098 }, 00202 {6.937,4.330,2.886,2.256,1.987,1.628,1.395,1.265, 00203 1.203,1.122,1.080,1.065,1.061,1.063,1.070,1.073, 00204 1.073,1.070,1.064,1.059,1.056,1.056 }, 00205 {9.616,5.708,3.424,2.551,2.204,1.762,1.485,1.330, 00206 1.256,1.155,1.099,1.077,1.070,1.068,1.072,1.074, 00207 1.074,1.070,1.063,1.059,1.056,1.052 }, 00208 {11.72,6.364,3.811,2.806,2.401,1.884,1.564,1.386, 00209 1.300,1.180,1.112,1.082,1.073,1.066,1.068,1.069, 00210 1.068,1.064,1.059,1.054,1.051,1.050 }, 00211 {18.08,8.601,4.569,3.183,2.662,2.025,1.646,1.439, 00212 1.339,1.195,1.108,1.068,1.053,1.040,1.039,1.039, 00213 1.039,1.037,1.034,1.031,1.030,1.036 }, 00214 {18.22,10.48,5.333,3.713,3.115,2.367,1.898,1.631, 00215 1.498,1.301,1.171,1.105,1.077,1.048,1.036,1.033, 00216 1.031,1.028,1.024,1.022,1.021,1.024 }, 00217 {14.14,10.65,5.710,3.929,3.266,2.453,1.951,1.669, 00218 1.528,1.319,1.178,1.106,1.075,1.040,1.027,1.022, 00219 1.020,1.017,1.015,1.013,1.013,1.020 }, 00220 {14.11,11.73,6.312,4.240,3.478,2.566,2.022,1.720, 00221 1.569,1.342,1.186,1.102,1.065,1.022,1.003,0.997, 00222 0.995,0.993,0.993,0.993,0.993,1.011 }, 00223 {22.76,20.01,8.835,5.287,4.144,2.901,2.219,1.855, 00224 1.677,1.410,1.224,1.121,1.073,1.014,0.986,0.976, 00225 0.974,0.972,0.973,0.974,0.975,0.987 }, 00226 {50.77,40.85,14.13,7.184,5.284,3.435,2.520,2.059, 00227 1.837,1.512,1.283,1.153,1.091,1.010,0.969,0.954, 00228 0.950,0.947,0.949,0.952,0.954,0.963 }, 00229 {65.87,59.06,15.87,7.570,5.567,3.650,2.682,2.182, 00230 1.939,1.579,1.325,1.178,1.108,1.014,0.965,0.947, 00231 0.941,0.938,0.940,0.944,0.946,0.954 }, 00232 {55.60,47.34,15.92,7.810,5.755,3.767,2.760,2.239, 00233 1.985,1.609,1.343,1.188,1.113,1.013,0.960,0.939, 00234 0.933,0.930,0.933,0.936,0.939,0.949 }}; 00235 00236 static const G4double cpositron[15][22] = { 00237 {2.589,2.044,1.658,1.446,1.347,1.217,1.144,1.110, 00238 1.097,1.083,1.080,1.086,1.092,1.108,1.123,1.131, 00239 1.131,1.126,1.117,1.108,1.103,1.100 }, 00240 {3.904,2.794,2.079,1.710,1.543,1.325,1.202,1.145, 00241 1.122,1.096,1.089,1.092,1.098,1.114,1.130,1.137, 00242 1.138,1.132,1.122,1.113,1.108,1.102 }, 00243 {7.970,6.080,4.442,3.398,2.872,2.127,1.672,1.451, 00244 1.357,1.246,1.194,1.179,1.178,1.188,1.201,1.205, 00245 1.203,1.190,1.173,1.159,1.151,1.145 }, 00246 {9.714,7.607,5.747,4.493,3.815,2.777,2.079,1.715, 00247 1.553,1.353,1.253,1.219,1.211,1.214,1.225,1.228, 00248 1.225,1.210,1.191,1.175,1.166,1.174 }, 00249 {17.97,12.95,8.628,6.065,4.849,3.222,2.275,1.820, 00250 1.624,1.382,1.259,1.214,1.202,1.202,1.214,1.219, 00251 1.217,1.203,1.184,1.169,1.160,1.151 }, 00252 {24.83,17.06,10.84,7.355,5.767,3.707,2.546,1.996, 00253 1.759,1.465,1.311,1.252,1.234,1.228,1.238,1.241, 00254 1.237,1.222,1.201,1.184,1.174,1.159 }, 00255 {23.26,17.15,11.52,8.049,6.375,4.114,2.792,2.155, 00256 1.880,1.535,1.353,1.281,1.258,1.247,1.254,1.256, 00257 1.252,1.234,1.212,1.194,1.183,1.170 }, 00258 {22.33,18.01,12.86,9.212,7.336,4.702,3.117,2.348, 00259 2.015,1.602,1.385,1.297,1.268,1.251,1.256,1.258, 00260 1.254,1.237,1.214,1.195,1.185,1.179 }, 00261 {33.91,24.13,15.71,10.80,8.507,5.467,3.692,2.808, 00262 2.407,1.873,1.564,1.425,1.374,1.330,1.324,1.320, 00263 1.312,1.288,1.258,1.235,1.221,1.205 }, 00264 {32.14,24.11,16.30,11.40,9.015,5.782,3.868,2.917, 00265 2.490,1.925,1.596,1.447,1.391,1.342,1.332,1.327, 00266 1.320,1.294,1.264,1.240,1.226,1.214 }, 00267 {29.51,24.07,17.19,12.28,9.766,6.238,4.112,3.066, 00268 2.602,1.995,1.641,1.477,1.414,1.356,1.342,1.336, 00269 1.328,1.302,1.270,1.245,1.231,1.233 }, 00270 {38.19,30.85,21.76,15.35,12.07,7.521,4.812,3.498, 00271 2.926,2.188,1.763,1.563,1.484,1.405,1.382,1.371, 00272 1.361,1.330,1.294,1.267,1.251,1.239 }, 00273 {49.71,39.80,27.96,19.63,15.36,9.407,5.863,4.155, 00274 3.417,2.478,1.944,1.692,1.589,1.480,1.441,1.423, 00275 1.409,1.372,1.330,1.298,1.280,1.258 }, 00276 {59.25,45.08,30.36,20.83,16.15,9.834,6.166,4.407, 00277 3.641,2.648,2.064,1.779,1.661,1.531,1.482,1.459, 00278 1.442,1.400,1.354,1.319,1.299,1.272 }, 00279 {56.38,44.29,30.50,21.18,16.51,10.11,6.354,4.542, 00280 3.752,2.724,2.116,1.817,1.692,1.554,1.499,1.474, 00281 1.456,1.412,1.364,1.328,1.307,1.282 }}; 00282 00283 //data/corrections for T > Tlim 00284 static const G4double Tlim = 10.*MeV; 00285 static const G4double beta2lim = Tlim*(Tlim+2.*electron_mass_c2)/ 00286 ((Tlim+electron_mass_c2)*(Tlim+electron_mass_c2)); 00287 static const G4double bg2lim = Tlim*(Tlim+2.*electron_mass_c2)/ 00288 (electron_mass_c2*electron_mass_c2); 00289 00290 static const G4double sig0[15] = { 00291 0.2672*barn, 0.5922*barn, 2.653*barn, 6.235*barn, 00292 11.69*barn , 13.24*barn , 16.12*barn, 23.00*barn , 00293 35.13*barn , 39.95*barn , 50.85*barn, 67.19*barn , 00294 91.15*barn , 104.4*barn , 113.1*barn}; 00295 00296 static const G4double hecorr[15] = { 00297 120.70, 117.50, 105.00, 92.92, 79.23, 74.510, 68.29, 00298 57.39, 41.97, 36.14, 24.53, 10.21, -7.855, -16.84, 00299 -22.30}; 00300 00301 G4double sigma; 00302 SetParticle(part); 00303 00304 Z23 = G4Pow::GetInstance()->Z23(G4lrint(AtomicNumber)); 00305 00306 // correction if particle .ne. e-/e+ 00307 // compute equivalent kinetic energy 00308 // lambda depends on p*beta .... 00309 00310 G4double eKineticEnergy = KineticEnergy; 00311 00312 if(mass > electron_mass_c2) 00313 { 00314 G4double TAU = KineticEnergy/mass ; 00315 G4double c = mass*TAU*(TAU+2.)/(electron_mass_c2*(TAU+1.)) ; 00316 G4double w = c-2. ; 00317 G4double tau = 0.5*(w+sqrt(w*w+4.*c)) ; 00318 eKineticEnergy = electron_mass_c2*tau ; 00319 } 00320 00321 G4double eTotalEnergy = eKineticEnergy + electron_mass_c2 ; 00322 G4double beta2 = eKineticEnergy*(eTotalEnergy+electron_mass_c2) 00323 /(eTotalEnergy*eTotalEnergy); 00324 G4double bg2 = eKineticEnergy*(eTotalEnergy+electron_mass_c2) 00325 /(electron_mass_c2*electron_mass_c2); 00326 00327 G4double eps = epsfactor*bg2/Z23; 00328 00329 if (eps<epsmin) sigma = 2.*eps*eps; 00330 else if(eps<epsmax) sigma = log(1.+2.*eps)-2.*eps/(1.+2.*eps); 00331 else sigma = log(2.*eps)-1.+1./eps; 00332 00333 sigma *= ChargeSquare*AtomicNumber*AtomicNumber/(beta2*bg2); 00334 00335 // interpolate in AtomicNumber and beta2 00336 G4double c1,c2,cc1,cc2,corr; 00337 00338 // get bin number in Z 00339 G4int iZ = 14; 00340 while ((iZ>=0)&&(Zdat[iZ]>=AtomicNumber)) iZ -= 1; 00341 if (iZ==14) iZ = 13; 00342 if (iZ==-1) iZ = 0 ; 00343 00344 G4double ZZ1 = Zdat[iZ]; 00345 G4double ZZ2 = Zdat[iZ+1]; 00346 G4double ratZ = (AtomicNumber-ZZ1)*(AtomicNumber+ZZ1)/ 00347 ((ZZ2-ZZ1)*(ZZ2+ZZ1)); 00348 00349 if(eKineticEnergy <= Tlim) 00350 { 00351 // get bin number in T (beta2) 00352 G4int iT = 21; 00353 while ((iT>=0)&&(Tdat[iT]>=eKineticEnergy)) iT -= 1; 00354 if(iT==21) iT = 20; 00355 if(iT==-1) iT = 0 ; 00356 00357 // calculate betasquare values 00358 G4double T = Tdat[iT], E = T + electron_mass_c2; 00359 G4double b2small = T*(E+electron_mass_c2)/(E*E); 00360 00361 T = Tdat[iT+1]; E = T + electron_mass_c2; 00362 G4double b2big = T*(E+electron_mass_c2)/(E*E); 00363 G4double ratb2 = (beta2-b2small)/(b2big-b2small); 00364 00365 if (charge < 0.) 00366 { 00367 c1 = celectron[iZ][iT]; 00368 c2 = celectron[iZ+1][iT]; 00369 cc1 = c1+ratZ*(c2-c1); 00370 00371 c1 = celectron[iZ][iT+1]; 00372 c2 = celectron[iZ+1][iT+1]; 00373 cc2 = c1+ratZ*(c2-c1); 00374 00375 corr = cc1+ratb2*(cc2-cc1); 00376 00377 sigma *= sigmafactor/corr; 00378 } 00379 else 00380 { 00381 c1 = cpositron[iZ][iT]; 00382 c2 = cpositron[iZ+1][iT]; 00383 cc1 = c1+ratZ*(c2-c1); 00384 00385 c1 = cpositron[iZ][iT+1]; 00386 c2 = cpositron[iZ+1][iT+1]; 00387 cc2 = c1+ratZ*(c2-c1); 00388 00389 corr = cc1+ratb2*(cc2-cc1); 00390 00391 sigma *= sigmafactor/corr; 00392 } 00393 } 00394 else 00395 { 00396 c1 = bg2lim*sig0[iZ]*(1.+hecorr[iZ]*(beta2-beta2lim))/bg2; 00397 c2 = bg2lim*sig0[iZ+1]*(1.+hecorr[iZ+1]*(beta2-beta2lim))/bg2; 00398 if((AtomicNumber >= ZZ1) && (AtomicNumber <= ZZ2)) 00399 sigma = c1+ratZ*(c2-c1) ; 00400 else if(AtomicNumber < ZZ1) 00401 sigma = AtomicNumber*AtomicNumber*c1/(ZZ1*ZZ1); 00402 else if(AtomicNumber > ZZ2) 00403 sigma = AtomicNumber*AtomicNumber*c2/(ZZ2*ZZ2); 00404 } 00405 return sigma; 00406 00407 }
Reimplemented from G4VMscModel.
Definition at line 660 of file G4UrbanMscModel96.cc.
References G4VMscModel::dtrl, G4UniformRand, G4VMscModel::GetEnergy(), G4VMscModel::GetTransportMeanFreePath(), and G4VMscModel::samplez.
00661 { 00662 firstStep = false; 00663 lambdaeff = lambda0; 00664 par1 = -1. ; 00665 par2 = par3 = 0. ; 00666 00667 // do the true -> geom transformation 00668 zPathLength = tPathLength; 00669 00670 // z = t for very small tPathLength 00671 if(tPathLength < tlimitminfix) return zPathLength; 00672 00673 // this correction needed to run MSC with eIoni and eBrem inactivated 00674 // and makes no harm for a normal run 00675 // It is already checked 00676 // if(tPathLength > currentRange) 00677 // tPathLength = currentRange ; 00678 00679 G4double tau = tPathLength/lambda0 ; 00680 00681 if ((tau <= tausmall) || insideskin) { 00682 zPathLength = tPathLength; 00683 if(zPathLength > lambda0) zPathLength = lambda0; 00684 return zPathLength; 00685 } 00686 00687 G4double zmean = tPathLength; 00688 if (tPathLength < currentRange*dtrl) { 00689 if(tau < taulim) zmean = tPathLength*(1.-0.5*tau) ; 00690 else zmean = lambda0*(1.-exp(-tau)); 00691 zPathLength = zmean ; 00692 return zPathLength; 00693 00694 } else if(currentKinEnergy < mass || tPathLength == currentRange) { 00695 par1 = 1./currentRange ; 00696 par2 = 1./(par1*lambda0) ; 00697 par3 = 1.+par2 ; 00698 if(tPathLength < currentRange) 00699 zmean = (1.-exp(par3*log(1.-tPathLength/currentRange)))/(par1*par3) ; 00700 else { 00701 zmean = 1./(par1*par3) ; 00702 } 00703 zPathLength = zmean ; 00704 return zPathLength; 00705 00706 } else { 00707 G4double T1 = GetEnergy(particle,currentRange-tPathLength,couple); 00708 G4double lambda1 = GetTransportMeanFreePath(particle,T1); 00709 00710 par1 = (lambda0-lambda1)/(lambda0*tPathLength); 00711 par2 = 1./(par1*lambda0); 00712 par3 = 1.+par2 ; 00713 zmean = (1.-exp(par3*log(lambda1/lambda0)))/(par1*par3); 00714 } 00715 00716 zPathLength = zmean; 00717 00718 // sample z 00719 if(samplez) 00720 { 00721 const G4double ztmax = 0.999 ; 00722 G4double zt = zmean/tPathLength ; 00723 00724 if (tPathLength > stepmin && zt < ztmax) 00725 { 00726 G4double u,cz1; 00727 if(zt >= third) 00728 { 00729 G4double cz = 0.5*(3.*zt-1.)/(1.-zt) ; 00730 cz1 = 1.+cz ; 00731 G4double u0 = cz/cz1 ; 00732 G4double grej ; 00733 do { 00734 u = exp(log(G4UniformRand())/cz1) ; 00735 grej = exp(cz*log(u/u0))*(1.-u)/(1.-u0) ; 00736 } while (grej < G4UniformRand()) ; 00737 } 00738 else 00739 { 00740 u = 2.*zt*G4UniformRand(); 00741 } 00742 zPathLength = tPathLength*u ; 00743 } 00744 } 00745 00746 if(zPathLength > lambda0) { zPathLength = lambda0; } 00747 //G4cout<< "zPathLength= "<< zPathLength<< " lambda1= " << lambda0 << G4endl; 00748 return zPathLength; 00749 }
Definition at line 793 of file G4UrbanMscModel96.cc.
00795 { 00796 // for all particles take the width of the central part 00797 // from a parametrization similar to the Highland formula 00798 // ( Highland formula: Particle Physics Booklet, July 2002, eq. 26.10) 00799 static const G4double c_highland = 13.6*MeV ; 00800 G4double betacp = sqrt(currentKinEnergy*(currentKinEnergy+2.*mass)* 00801 KineticEnergy*(KineticEnergy+2.*mass)/ 00802 ((currentKinEnergy+mass)*(KineticEnergy+mass))); 00803 y = trueStepLength/currentRadLength; 00804 G4double theta0 = c_highland*std::abs(charge)*sqrt(y)/betacp; 00805 y = log(y); 00806 // correction factor from e- scattering data 00807 G4double corr = coeffth1+coeffth2*y; 00808 00809 theta0 *= corr ; 00810 00811 return theta0; 00812 }
G4double G4UrbanMscModel96::ComputeTruePathLengthLimit | ( | const G4Track & | track, | |
G4double & | currentMinimalStep | |||
) | [virtual] |
Reimplemented from G4VMscModel.
Definition at line 424 of file G4UrbanMscModel96.cc.
References G4VMscModel::ComputeGeomLimit(), G4VMscModel::ComputeSafety(), G4VMscModel::ConvertTrueToGeom(), G4VMscModel::facgeom, G4VMscModel::facrange, G4VMscModel::facsafety, fGeomBoundary, fUseDistanceToBoundary, fUseSafety, G4Track::GetDynamicParticle(), G4MaterialCutsCouple::GetIndex(), G4DynamicParticle::GetKineticEnergy(), G4Track::GetMaterialCutsCouple(), G4Step::GetPreStepPoint(), G4VMscModel::GetRange(), G4Track::GetStep(), G4VMscModel::GetTransportMeanFreePath(), G4VEmModel::SetCurrentCouple(), G4VMscModel::skin, G4InuclParticleNames::sp, and G4VMscModel::steppingAlgorithm.
00427 { 00428 tPathLength = currentMinimalStep; 00429 const G4DynamicParticle* dp = track.GetDynamicParticle(); 00430 00431 G4StepPoint* sp = track.GetStep()->GetPreStepPoint(); 00432 G4StepStatus stepStatus = sp->GetStepStatus(); 00433 couple = track.GetMaterialCutsCouple(); 00434 SetCurrentCouple(couple); 00435 currentMaterialIndex = couple->GetIndex(); 00436 currentKinEnergy = dp->GetKineticEnergy(); 00437 currentRange = GetRange(particle,currentKinEnergy,couple); 00438 lambda0 = GetTransportMeanFreePath(particle,currentKinEnergy); 00439 if(tPathLength > currentRange) { tPathLength = currentRange; } 00440 00441 // stop here if small range particle 00442 if(inside || tPathLength < tlimitminfix) { 00443 return ConvertTrueToGeom(tPathLength, currentMinimalStep); 00444 } 00445 00446 presafety = sp->GetSafety(); 00447 /* 00448 G4cout << "G4Urban96::StepLimit tPathLength= " 00449 <<tPathLength<<" safety= " << presafety 00450 << " range= " <<currentRange<< " lambda= "<<lambda0 00451 << " Alg: " << steppingAlgorithm <<G4endl; 00452 */ 00453 // far from geometry boundary 00454 if(currentRange < presafety) 00455 { 00456 inside = true; 00457 return ConvertTrueToGeom(tPathLength, currentMinimalStep); 00458 } 00459 00460 // standard version 00461 // 00462 if (steppingAlgorithm == fUseDistanceToBoundary) 00463 { 00464 //compute geomlimit and presafety 00465 geomlimit = ComputeGeomLimit(track, presafety, currentRange); 00466 00467 // is it far from boundary ? 00468 if(currentRange < presafety) 00469 { 00470 inside = true; 00471 return ConvertTrueToGeom(tPathLength, currentMinimalStep); 00472 } 00473 00474 smallstep += 1.; 00475 insideskin = false; 00476 00477 if(firstStep || (stepStatus == fGeomBoundary)) 00478 { 00479 rangeinit = currentRange; 00480 if(firstStep) smallstep = 1.e10; 00481 else smallstep = 1.; 00482 00483 //define stepmin here (it depends on lambda!) 00484 //rough estimation of lambda_elastic/lambda_transport 00485 G4double rat = currentKinEnergy/MeV ; 00486 rat = 1.e-3/(rat*(10.+rat)) ; 00487 //stepmin ~ lambda_elastic 00488 stepmin = rat*lambda0; 00489 skindepth = skin*stepmin; 00490 //define tlimitmin 00491 tlimitmin = 10.*stepmin; 00492 if(tlimitmin < tlimitminfix) tlimitmin = tlimitminfix; 00493 //G4cout << "rangeinit= " << rangeinit << " stepmin= " << stepmin 00494 // << " tlimitmin= " << tlimitmin << " geomlimit= " << geomlimit <<G4endl; 00495 // constraint from the geometry 00496 if((geomlimit < geombig) && (geomlimit > geommin)) 00497 { 00498 // geomlimit is a geometrical step length 00499 // transform it to true path length (estimation) 00500 if((1.-geomlimit/lambda0) > 0.) 00501 geomlimit = -lambda0*log(1.-geomlimit/lambda0)+tlimitmin ; 00502 00503 if(stepStatus == fGeomBoundary) 00504 tgeom = geomlimit/facgeom; 00505 else 00506 tgeom = 2.*geomlimit/facgeom; 00507 } 00508 else 00509 tgeom = geombig; 00510 } 00511 00512 00513 //step limit 00514 tlimit = facrange*rangeinit; 00515 00516 //lower limit for tlimit 00517 if(tlimit < tlimitmin) tlimit = tlimitmin; 00518 00519 if(tlimit > tgeom) tlimit = tgeom; 00520 00521 //G4cout << "tgeom= " << tgeom << " geomlimit= " << geomlimit 00522 // << " tlimit= " << tlimit << " presafety= " << presafety << G4endl; 00523 00524 // shortcut 00525 if((tPathLength < tlimit) && (tPathLength < presafety) && 00526 (smallstep > skin) && (tPathLength < geomlimit-0.999*skindepth)) 00527 return ConvertTrueToGeom(tPathLength, currentMinimalStep); 00528 00529 // step reduction near to boundary 00530 if(smallstep <= skin) 00531 { 00532 tlimit = stepmin; 00533 insideskin = true; 00534 } 00535 else if(geomlimit < geombig) 00536 { 00537 if(geomlimit > skindepth) 00538 { 00539 if(tlimit > geomlimit-0.999*skindepth) 00540 tlimit = geomlimit-0.999*skindepth; 00541 } 00542 else 00543 { 00544 insideskin = true; 00545 if(tlimit > stepmin) tlimit = stepmin; 00546 } 00547 } 00548 00549 if(tlimit < stepmin) tlimit = stepmin; 00550 00551 // randomize 1st step or 1st 'normal' step in volume 00552 if(firstStep || ((smallstep == skin) && !insideskin)) 00553 { 00554 G4double temptlimit = tlimit; 00555 if(temptlimit > tlimitmin) 00556 { 00557 do { 00558 temptlimit = G4RandGauss::shoot(tlimit,0.3*tlimit); 00559 } while ((temptlimit < tlimitmin) || 00560 (temptlimit > 2.*tlimit-tlimitmin)); 00561 } 00562 else 00563 temptlimit = tlimitmin; 00564 if(tPathLength > temptlimit) tPathLength = temptlimit; 00565 } 00566 else 00567 { 00568 if(tPathLength > tlimit) tPathLength = tlimit ; 00569 } 00570 00571 } 00572 // for 'normal' simulation with or without magnetic field 00573 // there no small step/single scattering at boundaries 00574 else if(steppingAlgorithm == fUseSafety) 00575 { 00576 // compute presafety again if presafety <= 0 and no boundary 00577 // i.e. when it is needed for optimization purposes 00578 if((stepStatus != fGeomBoundary) && (presafety < tlimitminfix)) 00579 presafety = ComputeSafety(sp->GetPosition(),tPathLength); 00580 /* 00581 G4cout << "presafety= " << presafety 00582 << " firstStep= " << firstStep 00583 << " stepStatus= " << stepStatus 00584 << G4endl; 00585 */ 00586 // is far from boundary 00587 if(currentRange < presafety) 00588 { 00589 inside = true; 00590 return ConvertTrueToGeom(tPathLength, currentMinimalStep); 00591 } 00592 00593 if(firstStep || stepStatus == fGeomBoundary) 00594 { 00595 rangeinit = currentRange; 00596 fr = facrange; 00597 // 9.1 like stepping for e+/e- only (not for muons,hadrons) 00598 if(mass < masslimite) 00599 { 00600 if(lambda0 > currentRange) 00601 rangeinit = lambda0; 00602 if(lambda0 > lambdalimit) 00603 fr *= 0.75+0.25*lambda0/lambdalimit; 00604 } 00605 00606 //lower limit for tlimit 00607 G4double rat = currentKinEnergy/MeV ; 00608 rat = 1.e-3/(rat*(10.+rat)) ; 00609 stepmin = lambda0*rat; 00610 tlimitmin = 10.*stepmin; 00611 if(tlimitmin < tlimitminfix) tlimitmin = tlimitminfix; 00612 } 00613 //step limit 00614 tlimit = fr*rangeinit; 00615 00616 if(tlimit < facsafety*presafety) 00617 tlimit = facsafety*presafety; 00618 00619 //lower limit for tlimit 00620 if(tlimit < tlimitmin) tlimit = tlimitmin; 00621 00622 if(firstStep || stepStatus == fGeomBoundary) 00623 { 00624 G4double temptlimit = tlimit; 00625 if(temptlimit > tlimitmin) 00626 { 00627 do { 00628 temptlimit = G4RandGauss::shoot(tlimit,0.3*tlimit); 00629 } while ((temptlimit < tlimitmin) || 00630 (temptlimit > 2.*tlimit-tlimitmin)); 00631 } 00632 else 00633 temptlimit = tlimitmin; 00634 00635 if(tPathLength > temptlimit) tPathLength = temptlimit; 00636 } 00637 else 00638 if(tPathLength > tlimit) tPathLength = tlimit; 00639 } 00640 00641 // version similar to 7.1 (needed for some experiments) 00642 else 00643 { 00644 if (stepStatus == fGeomBoundary) 00645 { 00646 if (currentRange > lambda0) tlimit = facrange*currentRange; 00647 else tlimit = facrange*lambda0; 00648 00649 if(tlimit < tlimitmin) tlimit = tlimitmin; 00650 if(tPathLength > tlimit) tPathLength = tlimit; 00651 } 00652 } 00653 //G4cout << "tPathLength= " << tPathLength 00654 // << " currentMinimalStep= " << currentMinimalStep << G4endl; 00655 return ConvertTrueToGeom(tPathLength, currentMinimalStep); 00656 }
Reimplemented from G4VMscModel.
Definition at line 753 of file G4UrbanMscModel96.cc.
00754 { 00755 // step defined other than transportation 00756 if(geomStepLength == zPathLength) 00757 { return tPathLength; } 00758 00759 zPathLength = geomStepLength; 00760 00761 // t = z for very small step 00762 if(geomStepLength < tlimitminfix) { 00763 tPathLength = geomStepLength; 00764 00765 // recalculation 00766 } else { 00767 00768 G4double tlength = geomStepLength; 00769 if((geomStepLength > lambda0*tausmall) && !insideskin) { 00770 00771 if(par1 < 0.) { 00772 tlength = -lambda0*log(1.-geomStepLength/lambda0) ; 00773 } else { 00774 if(par1*par3*geomStepLength < 1.) { 00775 tlength = (1.-exp(log(1.-par1*par3*geomStepLength)/par3))/par1 ; 00776 } else { 00777 tlength = currentRange; 00778 } 00779 } 00780 if(tlength < geomStepLength) { tlength = geomStepLength; } 00781 else if(tlength > tPathLength) { tlength = tPathLength; } 00782 } 00783 tPathLength = tlength; 00784 } 00785 //G4cout << "Urban96::ComputeTrueLength: tPathLength= " << tPathLength 00786 // << " step= " << geomStepLength << G4endl; 00787 00788 return tPathLength; 00789 }
void G4UrbanMscModel96::Initialise | ( | const G4ParticleDefinition * | , | |
const G4DataVector & | ||||
) | [virtual] |
Implements G4VEmModel.
Definition at line 142 of file G4UrbanMscModel96.cc.
References G4VMscModel::GetParticleChangeForMSC(), and G4VMscModel::skin.
00144 { 00145 skindepth = skin*stepmin; 00146 // trackID = -1; 00147 00148 // set values of some data members 00149 SetParticle(p); 00150 /* 00151 if(p->GetPDGMass() > MeV) { 00152 G4cout << "### WARNING: G4UrbanMscModel96 model is used for " 00153 << p->GetParticleName() << " !!! " << G4endl; 00154 G4cout << "### This model should be used only for e+-" 00155 << G4endl; 00156 } 00157 */ 00158 fParticleChange = GetParticleChangeForMSC(p); 00159 00160 //samplez = true; 00161 //G4cout << "### G4UrbanMscModel96::Initialise done!" << G4endl; 00162 }
G4ThreeVector & G4UrbanMscModel96::SampleScattering | ( | const G4ThreeVector & | , | |
G4double | safety | |||
) | [virtual] |
Reimplemented from G4VMscModel.
Definition at line 817 of file G4UrbanMscModel96.cc.
References G4VMscModel::dtrl, G4VMscModel::fDisplacement, G4UniformRand, G4VMscModel::GetDEDX(), G4VMscModel::GetEnergy(), G4VMscModel::latDisplasment, and G4ParticleChangeForMSC::ProposeMomentumDirection().
00819 { 00820 fDisplacement.set(0.0,0.0,0.0); 00821 G4double kineticEnergy = currentKinEnergy; 00822 if (tPathLength > currentRange*dtrl) { 00823 kineticEnergy = GetEnergy(particle,currentRange-tPathLength,couple); 00824 } else { 00825 kineticEnergy -= tPathLength*GetDEDX(particle,currentKinEnergy,couple); 00826 } 00827 00828 if((kineticEnergy <= eV) || (tPathLength <= tlimitminfix) || 00829 (tPathLength/tausmall < lambda0)) { return fDisplacement; } 00830 00831 G4double cth = SampleCosineTheta(tPathLength,kineticEnergy); 00832 00833 // protection against 'bad' cth values 00834 if(std::fabs(cth) > 1.) { return fDisplacement; } 00835 00836 // extra protection agaist high energy particles backscattered 00837 //G4cout << "Warning: large scattering E(MeV)= " << kineticEnergy 00838 // << " s(mm)= " << tPathLength/mm 00839 // << " 1-cosTheta= " << 1.0 - cth << G4endl; 00840 // do Gaussian central scattering 00841 // if(kineticEnergy > 5*GeV && cth < 0.9) { 00842 /* 00843 if(cth < 1.0 - 1000*tPathLength/lambda0 00844 && cth < 0.8 && kineticEnergy > 20*MeV) { 00845 G4ExceptionDescription ed; 00846 ed << particle->GetParticleName() 00847 << " E(MeV)= " << kineticEnergy/MeV 00848 << " Step(mm)= " << tPathLength/mm 00849 << " in " << CurrentCouple()->GetMaterial()->GetName() 00850 << " CosTheta= " << cth 00851 << " is too big"; 00852 G4Exception("G4UrbanMscModel96::SampleScattering","em0004", 00853 JustWarning, ed,""); 00854 00855 if(kineticEnergy > GeV && cth < 0.0) { 00856 do { 00857 cth = 1.0 + 2*log(G4UniformRand())*tPathLength/lambda0; 00858 } while(cth < -1.0); 00859 } 00860 */ 00861 00862 G4double sth = sqrt((1.0 - cth)*(1.0 + cth)); 00863 G4double phi = twopi*G4UniformRand(); 00864 G4double dirx = sth*cos(phi); 00865 G4double diry = sth*sin(phi); 00866 00867 G4ThreeVector newDirection(dirx,diry,cth); 00868 newDirection.rotateUz(oldDirection); 00869 fParticleChange->ProposeMomentumDirection(newDirection); 00870 /* 00871 G4cout << "G4UrbanMscModel96::SampleSecondaries: e(MeV)= " << kineticEnergy 00872 << " sinTheta= " << sth << " safety(mm)= " << safety 00873 << " trueStep(mm)= " << tPathLength 00874 << " geomStep(mm)= " << zPathLength 00875 << G4endl; 00876 */ 00877 if (latDisplasment && safety > tlimitminfix) { 00878 00879 G4double r = SampleDisplacement(); 00880 /* 00881 G4cout << "G4UrbanMscModel96::SampleSecondaries: e(MeV)= " << kineticEnergy 00882 << " sinTheta= " << sth << " r(mm)= " << r 00883 << " trueStep(mm)= " << tPathLength 00884 << " geomStep(mm)= " << zPathLength 00885 << G4endl; 00886 */ 00887 if(r > 0.) 00888 { 00889 G4double latcorr = LatCorrelation(); 00890 if(latcorr > r) latcorr = r; 00891 00892 // sample direction of lateral displacement 00893 // compute it from the lateral correlation 00894 G4double Phi = 0.; 00895 if(std::abs(r*sth) < latcorr) 00896 Phi = twopi*G4UniformRand(); 00897 else 00898 { 00899 G4double psi = std::acos(latcorr/(r*sth)); 00900 if(G4UniformRand() < 0.5) 00901 Phi = phi+psi; 00902 else 00903 Phi = phi-psi; 00904 } 00905 00906 dirx = std::cos(Phi); 00907 diry = std::sin(Phi); 00908 00909 fDisplacement.set(r*dirx,r*diry,0.0); 00910 fDisplacement.rotateUz(oldDirection); 00911 } 00912 } 00913 return fDisplacement; 00914 }
void G4UrbanMscModel96::StartTracking | ( | G4Track * | ) | [virtual] |
Reimplemented from G4VEmModel.
Definition at line 411 of file G4UrbanMscModel96.cc.
References G4DynamicParticle::GetDefinition(), and G4Track::GetDynamicParticle().
00412 { 00413 SetParticle(track->GetDynamicParticle()->GetDefinition()); 00414 firstStep = true; 00415 inside = false; 00416 insideskin = false; 00417 tlimit = geombig; 00418 stepmin = tlimitminfix ; 00419 tlimitmin = 10.*stepmin ; 00420 }