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1 // 1 2 // ******************************************* 3 // * License and Disclaimer 4 // * 5 // * The Geant4 software is copyright of th 6 // * the Geant4 Collaboration. It is provided 7 // * conditions of the Geant4 Software License 8 // * LICENSE and available at http://cern.ch/ 9 // * include a list of copyright holders. 10 // * 11 // * Neither the authors of this software syst 12 // * institutes,nor the agencies providing fin 13 // * work make any representation or warran 14 // * regarding this software system or assum 15 // * use. Please see the license in the file 16 // * for the full disclaimer and the limitatio 17 // * 18 // * This code implementation is the result 19 // * technical work of the GEANT4 collaboratio 20 // * By using, copying, modifying or distri 21 // * any work based on the software) you ag 22 // * use in resulting scientific publicati 23 // * acceptance of all terms of the Geant4 Sof 24 // ******************************************* 25 // 26 // 27 // ------------------------------------------- 28 // 29 // GEANT4 Class file 30 // 31 // 32 // File name: G4IonFluctuation 33 // 34 // Author: Vladimir Ivanchenko 35 // 36 // Creation date: 03.01.2002 37 // 38 // Modifications: 39 // 40 // 28-12-02 add method Dispersion (V.Ivanchenk 41 // 07-02-03 change signature (V.Ivanchenko) 42 // 13-02-03 Add name (V.Ivanchenko) 43 // 23-05-03 Add control on parthalogical cases 44 // 16-10-03 Changed interface to Initialisatio 45 // 27-09-07 Use FermiEnergy from material, add 46 // 01-02-08 Add protection for small energies 47 // 01-06-08 Added initialisation of effective 48 // 49 // Class Description: 50 // 51 // ------------------------------------------- 52 // 53 54 //....oooOO0OOooo........oooOO0OOooo........oo 55 //....oooOO0OOooo........oooOO0OOooo........oo 56 57 #include "G4IonFluctuations.hh" 58 #include "G4UniversalFluctuation.hh" 59 #include "G4PhysicalConstants.hh" 60 #include "G4SystemOfUnits.hh" 61 #include "Randomize.hh" 62 #include "G4Poisson.hh" 63 #include "G4MaterialCutsCouple.hh" 64 #include "G4Material.hh" 65 #include "G4DynamicParticle.hh" 66 #include "G4Pow.hh" 67 #include "G4Log.hh" 68 69 //....oooOO0OOooo........oooOO0OOooo........oo 70 71 using namespace std; 72 73 G4IonFluctuations::G4IonFluctuations(const G4S 74 : G4VEmFluctuationModel(nam), 75 particleMass(CLHEP::proton_mass_c2), 76 parameter(10.0*CLHEP::MeV/CLHEP::proton_ma 77 theBohrBeta2(50.0*keV/CLHEP::proton_mass_c 78 minLoss(0.001*CLHEP::eV) 79 { 80 uniFluct = new G4UniversalFluctuation(); 81 g4calc = G4Pow::GetInstance(); 82 } 83 84 //....oooOO0OOooo........oooOO0OOooo........oo 85 86 G4IonFluctuations::~G4IonFluctuations() = defa 87 88 //....oooOO0OOooo........oooOO0OOooo........oo 89 90 void G4IonFluctuations::InitialiseMe(const G4P 91 { 92 particle = part; 93 particleMass = part->GetPDGMass(); 94 charge = part->GetPDGCharge()/eplus; 95 effChargeSquare = chargeSquare = charge*char 96 uniFluct->InitialiseMe(part); 97 } 98 99 //....oooOO0OOooo........oooOO0OOooo........oo 100 101 G4double 102 G4IonFluctuations::SampleFluctuations(const G4 103 const G4 104 const G4 105 const G4 106 const G4 107 const G4 108 { 109 // G4cout << "### meanLoss= " << meanLoss < 110 if(meanLoss <= minLoss) return meanLoss; 111 112 //G4cout << "G4IonFluctuations::SampleFluctu 113 // << dp->GetKineticEnergy() 114 // << " Elim(MeV)= " << parameter*c 115 116 // Vavilov fluctuations above energy thresho 117 if(dp->GetKineticEnergy() > parameter*charge 118 return uniFluct->SampleFluctuations(couple 119 } 120 121 const G4Material* material = couple->GetMate 122 G4double siga = Dispersion(material,dp,tcut, 123 G4double loss = meanLoss; 124 125 //G4cout << "### siga= " << sqrt(siga) << " 126 127 // Gaussian fluctuation 128 129 // Increase fluctuations for big fractional 130 //G4cout << "siga= " << siga << G4endl; 131 if ( meanLoss > minFraction*kineticEnergy ) 132 G4double gam = (kineticEnergy - meanLoss)/ 133 G4double b2 = 1.0 - 1.0/(gam*gam); 134 if(b2 < xmin*beta2) b2 = xmin*beta2; 135 G4double x = b2/beta2; 136 G4double x3 = 1.0/(x*x*x); 137 siga *= 0.25*(1.0 + x)*(x3 + (1.0/b2 - 0.5 138 } 139 siga = std::sqrt(siga); 140 G4double sn = meanLoss/siga; 141 G4double twomeanLoss = meanLoss + meanLoss; 142 // G4cout << "siga= " << siga << " sn= " < 143 144 CLHEP::HepRandomEngine* rndmEngine = G4Rando 145 // thick target case 146 if (sn >= 2.0) { 147 148 do { 149 loss = G4RandGauss::shoot(rndmEngine,mea 150 // Loop checking, 03-Aug-2015, Vladimir 151 } while (0.0 > loss || twomeanLoss < loss) 152 153 // Gamma distribution 154 } else if(sn > 0.1) { 155 156 G4double neff = sn*sn; 157 loss = meanLoss*G4RandGamma::shoot(rndmEng 158 159 // uniform distribution for very small ste 160 } else { 161 loss = twomeanLoss*rndmEngine->flat(); 162 } 163 164 //G4cout << "meanLoss= " << meanLoss << " lo 165 return loss; 166 } 167 168 //....oooOO0OOooo........oooOO0OOooo........oo 169 170 G4double G4IonFluctuations::Dispersion(const G 171 const G 172 const G 173 const G 174 const G 175 { 176 if(dp->GetDefinition() != particle) { Initia 177 178 const G4double beta = dp->GetBeta(); 179 kineticEnergy = dp->GetKineticEnergy(); 180 beta2 = beta*beta; 181 182 G4double siga = (tmax/beta2 - 0.5*tcut)*CLHE 183 material->GetElectronDensity()*effChargeSq 184 185 // Low velocity - additional ion charge fluc 186 // Q.Yang et al., NIM B61(1991)149-155. 187 //G4cout << "sigE= " << sqrt(siga) << " char 188 189 G4double Z = material->GetIonisation()->GetZ 190 G4double fac = Factor(material, Z); 191 192 // heavy ion correction 193 // G4double f1 = 1.065e-4*chargeSquare; 194 // if(beta2 > theBohrBeta2) f1/= beta2; 195 // else f1/= theBohrBe 196 // if(f1 > 2.5) f1 = 2.5; 197 // fac *= (1.0 + f1); 198 199 // taking into account the cutg 200 G4double fac_cut = 1.0 + (fac - 1.0)*2.0*CLH 201 /(tmax*(1.0 - beta2)); 202 if(fac_cut > 0.01 && fac > 0.01) { 203 siga *= fac_cut; 204 } 205 /* 206 G4cout << "siga(keV)= " << sqrt(siga)/keV << 207 << " f1= " << fac_cut << G4endl; 208 */ 209 return siga; 210 } 211 212 //....oooOO0OOooo........oooOO0OOooo........oo 213 214 G4double G4IonFluctuations::Factor(const G4Mat 215 { 216 // The aproximation of energy loss fluctuati 217 // Q.Yang et al., NIM B61(1991)149-155. 218 219 // Reduced energy in MeV/AMU 220 G4double energy = kineticEnergy*CLHEP::amu_c 221 222 // simple approximation for higher beta2 223 G4double s1 = RelativisticFactor(material, Z 224 225 // tabulation for lower beta2 226 if( beta2 < 3.0*theBohrBeta2*Z ) { 227 228 static const G4double a[96][4] = { 229 {-0.3291, -0.8312, 0.2460, -1.0220}, 230 {-0.5615, -0.5898, 0.5205, -0.7258}, 231 {-0.5280, -0.4981, 0.5519, -0.5865}, 232 {-0.5125, -0.4625, 0.5660, -0.5190}, 233 {-0.5127, -0.8595, 0.5626, -0.8721}, 234 {-0.5174, -1.1930, 0.5565, -1.1980}, 235 {-0.5179, -1.1850, 0.5560, -1.2070}, 236 {-0.5209, -0.9355, 0.5590, -1.0250}, 237 {-0.5255, -0.7766, 0.5720, -0.9412}, 238 239 {-0.5776, -0.6665, 0.6598, -0.8484}, 240 {-0.6013, -0.6045, 0.7321, -0.7671}, 241 {-0.5781, -0.5518, 0.7605, -0.6919}, 242 {-0.5587, -0.4981, 0.7835, -0.6195}, 243 {-0.5466, -0.4656, 0.7978, -0.5771}, 244 {-0.5406, -0.4690, 0.8031, -0.5718}, 245 {-0.5391, -0.5061, 0.8024, -0.5974}, 246 {-0.5380, -0.6483, 0.7962, -0.6970}, 247 {-0.5355, -0.7722, 0.7962, -0.7839}, 248 {-0.5329, -0.7720, 0.7988, -0.7846}, 249 250 {-0.5335, -0.7671, 0.7984, -0.7933}, 251 {-0.5324, -0.7612, 0.7998, -0.8031}, 252 {-0.5305, -0.7300, 0.8031, -0.7990}, 253 {-0.5307, -0.7178, 0.8049, -0.8216}, 254 {-0.5248, -0.6621, 0.8165, -0.7919}, 255 {-0.5180, -0.6502, 0.8266, -0.7986}, 256 {-0.5084, -0.6408, 0.8396, -0.8048}, 257 {-0.4967, -0.6331, 0.8549, -0.8093}, 258 {-0.4861, -0.6508, 0.8712, -0.8432}, 259 {-0.4700, -0.6186, 0.8961, -0.8132}, 260 261 {-0.4545, -0.5720, 0.9227, -0.7710}, 262 {-0.4404, -0.5226, 0.9481, -0.7254}, 263 {-0.4288, -0.4778, 0.9701, -0.6850}, 264 {-0.4199, -0.4425, 0.9874, -0.6539}, 265 {-0.4131, -0.4188, 0.9998, -0.6332}, 266 {-0.4089, -0.4057, 1.0070, -0.6218}, 267 {-0.4039, -0.3913, 1.0150, -0.6107}, 268 {-0.3987, -0.3698, 1.0240, -0.5938}, 269 {-0.3977, -0.3608, 1.0260, -0.5852}, 270 {-0.3972, -0.3600, 1.0260, -0.5842}, 271 272 {-0.3985, -0.3803, 1.0200, -0.6013}, 273 {-0.3985, -0.3979, 1.0150, -0.6168}, 274 {-0.3968, -0.3990, 1.0160, -0.6195}, 275 {-0.3971, -0.4432, 1.0050, -0.6591}, 276 {-0.3944, -0.4665, 1.0010, -0.6825}, 277 {-0.3924, -0.5109, 0.9921, -0.7235}, 278 {-0.3882, -0.5158, 0.9947, -0.7343}, 279 {-0.3838, -0.5125, 0.9999, -0.7370}, 280 {-0.3786, -0.4976, 1.0090, -0.7310}, 281 {-0.3741, -0.4738, 1.0200, -0.7155}, 282 283 {-0.3969, -0.4496, 1.0320, -0.6982}, 284 {-0.3663, -0.4297, 1.0430, -0.6828}, 285 {-0.3630, -0.4120, 1.0530, -0.6689}, 286 {-0.3597, -0.3964, 1.0620, -0.6564}, 287 {-0.3555, -0.3809, 1.0720, -0.6454}, 288 {-0.3525, -0.3607, 1.0820, -0.6289}, 289 {-0.3505, -0.3465, 1.0900, -0.6171}, 290 {-0.3397, -0.3570, 1.1020, -0.6384}, 291 {-0.3314, -0.3552, 1.1130, -0.6441}, 292 {-0.3235, -0.3531, 1.1230, -0.6498}, 293 294 {-0.3150, -0.3483, 1.1360, -0.6539}, 295 {-0.3060, -0.3441, 1.1490, -0.6593}, 296 {-0.2968, -0.3396, 1.1630, -0.6649}, 297 {-0.2935, -0.3225, 1.1760, -0.6527}, 298 {-0.2797, -0.3262, 1.1940, -0.6722}, 299 {-0.2704, -0.3202, 1.2100, -0.6770}, 300 {-0.2815, -0.3227, 1.2480, -0.6775}, 301 {-0.2880, -0.3245, 1.2810, -0.6801}, 302 {-0.3034, -0.3263, 1.3270, -0.6778}, 303 {-0.2936, -0.3215, 1.3430, -0.6835}, 304 305 {-0.3282, -0.3200, 1.3980, -0.6650}, 306 {-0.3260, -0.3070, 1.4090, -0.6552}, 307 {-0.3511, -0.3074, 1.4470, -0.6442}, 308 {-0.3501, -0.3064, 1.4500, -0.6442}, 309 {-0.3490, -0.3027, 1.4550, -0.6418}, 310 {-0.3487, -0.3048, 1.4570, -0.6447}, 311 {-0.3478, -0.3074, 1.4600, -0.6483}, 312 {-0.3501, -0.3283, 1.4540, -0.6669}, 313 {-0.3494, -0.3373, 1.4550, -0.6765}, 314 {-0.3485, -0.3373, 1.4570, -0.6774}, 315 316 {-0.3462, -0.3300, 1.4630, -0.6728}, 317 {-0.3462, -0.3225, 1.4690, -0.6662}, 318 {-0.3453, -0.3094, 1.4790, -0.6553}, 319 {-0.3844, -0.3134, 1.5240, -0.6412}, 320 {-0.3848, -0.3018, 1.5310, -0.6303}, 321 {-0.3862, -0.2955, 1.5360, -0.6237}, 322 {-0.4262, -0.2991, 1.5860, -0.6115}, 323 {-0.4278, -0.2910, 1.5900, -0.6029}, 324 {-0.4303, -0.2817, 1.5940, -0.5927}, 325 {-0.4315, -0.2719, 1.6010, -0.5829}, 326 327 {-0.4359, -0.2914, 1.6050, -0.6010}, 328 {-0.4365, -0.2982, 1.6080, -0.6080}, 329 {-0.4253, -0.3037, 1.6120, -0.6150}, 330 {-0.4335, -0.3245, 1.6160, -0.6377}, 331 {-0.4307, -0.3292, 1.6210, -0.6447}, 332 {-0.4284, -0.3204, 1.6290, -0.6380}, 333 {-0.4227, -0.3217, 1.6360, -0.6438} 334 } ; 335 336 G4int iz = G4lrint(Z) - 2; 337 if( 0 > iz ) { iz = 0; } 338 else if(95 < iz ) { iz = 95; } 339 340 const G4double ss = 1.0 + a[iz][0]*g4calc- 341 + a[iz][2]*g4calc->powA(energy,a[iz][3]) 342 343 // protection for the validity range for l 344 static const G4double slim = 0.001; 345 if(ss < slim) { s1 = 1.0/slim; } 346 // for high value of beta 347 else if(s1*ss < 1.0) { s1 = 1.0/ss; } 348 } 349 G4int i = 0 ; 350 G4double factor = 1.0 ; 351 352 // The index of set of parameters i = 0 for 353 // 1 for 354 // 2 for 355 // 3 for 356 // 4 for 357 static const G4double b[5][4] = { 358 {0.1014, 0.3700, 0.9642, 3.987}, 359 {0.1955, 0.6941, 2.522, 1.040}, 360 {0.05058, 0.08975, 0.1419, 10.80}, 361 {0.05009, 0.08660, 0.2751, 3.787}, 362 {0.01273, 0.03458, 0.3951, 3.812} 363 } ; 364 365 // protons (hadrons) 366 if(1.5 > charge) { 367 if( kStateGas != material->GetState() ) { 368 369 // ions 370 } else { 371 372 factor = charge * g4calc->A13(charge/Z); 373 374 if( kStateGas == material->GetState() ) { 375 energy /= (charge * std::sqrt(charge)) ; 376 377 if(1 == (material->GetNumberOfElements() 378 i = 2 ; 379 } else { 380 i = 3 ; 381 } 382 383 } else { 384 energy /= (charge * std::sqrt(charge*Z)) 385 i = 4 ; 386 } 387 } 388 389 G4double x = b[i][2]; 390 G4double y = energy * b[i][3]; 391 if(y <= 0.2) x *= (y*(1.0 - 0.5*y)); 392 else x *= (1.0 - g4calc->expA(-y)); 393 394 y = energy - b[i][1]; 395 396 const G4double s2 = factor * x * b[i][0] / ( 397 /* 398 G4cout << "s1= " << s1 << " s2= " << s2 << " 399 << " e= " << energy << G4endl; 400 */ 401 return s1*effChargeSquare/chargeSquare + s2; 402 } 403 404 //....oooOO0OOooo........oooOO0OOooo........oo 405 406 G4double G4IonFluctuations::RelativisticFactor 407 408 { 409 G4double eF = mat->GetIonisation()->GetFermi 410 G4double I = mat->GetIonisation()->GetMeanE 411 412 // H.Geissel et al. NIM B, 195 (2002) 3. 413 G4double bF2= 2.0*eF/CLHEP::electron_mass_c2 414 G4double f = 0.4*(1.0 - beta2)/((1.0 - 0.5* 415 if(beta2 > bF2) f *= G4Log(2.0*CLHEP::electr 416 else f *= G4Log(4.0*eF/I); 417 418 // G4cout << "f= " << f << " beta2= " << be 419 // << " bf2= " << bF2 << " q^2= " << 420 421 return 1.0 + f; 422 } 423 424 //....oooOO0OOooo........oooOO0OOooo........oo 425 426 void G4IonFluctuations::SetParticleAndCharge(c 427 G 428 { 429 if(part != particle) { 430 particle = part; 431 particleMass = part->GetPDGMass(); 432 charge = part->GetPDGCharge()/eplu 433 chargeSquare = charge*charge; 434 } 435 effChargeSquare = q2; 436 uniFluct->SetParticleAndCharge(part, q2); 437 } 438 439 //....oooOO0OOooo........oooOO0OOooo........oo 440