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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: G4RDPhotoElectricAngularGene 33 // 34 // Author: A. C. Farinha, L. Peralta, P. Rodri 35 // 36 // Creation date: 37 // 38 // Modifications: 39 // 10 January 2006 40 // 41 // Class Description: 42 // 43 // Concrete class for PhotoElectric Electron A 44 // 45 // Class Description: 46 // PhotoElectric Electron Angular Generator ba 47 // Includes polarization effects for K and L1 48 // For higher shells the L1 cross-section is u 49 // 50 // The Gavrila photoelectron angular distribut 51 // the inverse-transform method (James 1980). 52 // used to sample bremsstrahlung 2BN cross sec 53 // 54 // M. Gavrila, "Relativistic K-Shell Photoeffe 55 // M. Gavrila, "Relativistic L-Shell Photoeffe 56 // F. James, Rept. on Prog. in Phys. 43, 1145 57 // L. Peralta et al., "A new low-energy bremss 58 // 59 // 60 // ------------------------------------------- 61 // 62 // 63 64 #include "G4RDPhotoElectricAngularGeneratorPol 65 #include "G4RotationMatrix.hh" 66 #include "Randomize.hh" 67 #include "G4PhysicalConstants.hh" 68 69 // 70 71 G4RDPhotoElectricAngularGeneratorPolarized::G4 72 { 73 const G4int arrayDim = 980; 74 75 //minimum electron beta parameter allowed 76 betaArray[0] = 0.02; 77 //beta step 78 betaArray[1] = 0.001; 79 //maximum index array for a and c tables 80 betaArray[2] = arrayDim - 1; 81 82 // read Majorant Surface Parameters. This ar 83 for(G4int level = 0; level < 2; level++){ 84 85 char nameChar0[100] = "ftab0.dat"; // K-sh 86 char nameChar1[100] = "ftab1.dat"; // L-sh 87 88 G4String filename; 89 if(level == 0) filename = nameChar0; 90 if(level == 1) filename = nameChar1; 91 92 const char* path = G4FindDataDir("G4LEDATA 93 if (!path) 94 { 95 G4String excep = "G4LEDATA environment 96 G4Exception("G4RDPhotoElectricAngularG 97 "InvalidSetup", FatalExcep 98 } 99 100 G4String pathString(path); 101 G4String dirFile = pathString + "/photoele 102 FILE *infile; 103 infile = fopen(dirFile,"r"); 104 if (infile == 0) 105 { 106 G4String excep = "Data file: " + dirFile + " 107 G4Exception("G4RDPhotoElectricAngularGenerat 108 "DataNotFound", FatalExcep 109 } 110 111 // Read parameters into tables. The parame 112 G4float aRead,cRead, beta; 113 for(G4int i=0 ; i<arrayDim ;i++){ 114 fscanf(infile,"%f\t %e\t %e",&beta,&aRea 115 aMajorantSurfaceParameterTable[i][level] 116 cMajorantSurfaceParameterTable[i][level] 117 } 118 fclose(infile); 119 120 } 121 } 122 123 // 124 125 G4RDPhotoElectricAngularGeneratorPolarized::~G 126 {;} 127 128 // 129 130 G4ThreeVector G4RDPhotoElectricAngularGenerato 131 const G4ThreeVector& pol 132 { 133 // Calculate Lorentz term (gamma) and beta p 134 G4double gamma = 1. + eKineticEnergy/elect 135 G4double beta = std::sqrt(gamma*gamma-1.)/g 136 137 G4double theta, phi = 0; 138 G4double aBeta = 0; // Majorant surface para 139 G4double cBeta = 0; // Majorant surface para 140 141 G4int shellLevel = 0; 142 if(shellId < 2) shellLevel = 0; // K-shell 143 if(shellId >= 2) shellLevel = 1; // L1-shell 144 145 // For the outgoing kinetic energy find the 146 PhotoElectronGetMajorantSurfaceAandCParamete 147 148 // Generate pho and theta according to the s 149 PhotoElectronGeneratePhiAndTheta(shellLevel, 150 151 // Determine the rotation matrix 152 G4RotationMatrix rotation = PhotoElectronRot 153 154 // Compute final direction of the outgoing e 155 G4ThreeVector final_direction = PhotoElectro 156 157 return final_direction; 158 } 159 160 // 161 162 void G4RDPhotoElectricAngularGeneratorPolarize 163 const G4double aBeta 164 G4double *pphi, G4do 165 { 166 G4double rand1, rand2, rand3 = 0; 167 G4double phi = 0; 168 G4double theta = 0; 169 G4double crossSectionValue = 0; 170 G4double crossSectionMajorantFunctionValue = 171 G4double maxBeta = 0; 172 173 do { 174 175 rand1 = G4UniformRand(); 176 rand2 = G4UniformRand(); 177 rand3 = G4UniformRand(); 178 179 phi=2*pi*rand1; 180 181 if(shellLevel == 0){ 182 183 // Polarized Gavrila Cross-Section for K 184 theta=std::sqrt(((std::exp(rand2*std::lo 185 crossSectionMajorantFunctionValue = Cros 186 crossSectionValue = DSigmaKshellGavrila1 187 188 } else { 189 190 // Polarized Gavrila Cross-Section for 191 theta = std::sqrt(((std::exp(rand2*std:: 192 crossSectionMajorantFunctionValue = Cros 193 crossSectionValue = DSigmaL1shellGavrila 194 195 } 196 197 maxBeta=rand3*aBeta*crossSectionMajorantFu 198 199 }while(maxBeta > crossSectionValue); 200 201 *pphi = phi; 202 *ptheta = theta; 203 } 204 205 // 206 207 G4double G4RDPhotoElectricAngularGeneratorPola 208 { 209 // Compute Majorant Function 210 G4double crossSectionMajorantFunctionValue = 211 crossSectionMajorantFunctionValue = theta/(1 212 return crossSectionMajorantFunctionValue; 213 } 214 215 // 216 217 G4double G4RDPhotoElectricAngularGeneratorPola 218 { 219 220 //Double differential K shell cross-section 221 222 G4double beta2 = beta*beta; 223 G4double oneBeta2 = 1 - beta2; 224 G4double sqrtOneBeta2 = std::sqrt(oneBeta2); 225 G4double oneBeta2_to_3_2 = std::pow(oneBeta2 226 G4double cosTheta = std::cos(theta); 227 G4double sinTheta2 = std::sin(theta)*std::si 228 G4double cosPhi2 = std::cos(phi)*std::cos(ph 229 G4double oneBetaCosTheta = 1-beta*cosTheta; 230 G4double dsigma = 0; 231 G4double firstTerm = 0; 232 G4double secondTerm = 0; 233 234 firstTerm = sinTheta2*cosPhi2/std::pow(oneBe 235 (sinTheta2 * cosPhi2)/std::pow(o 236 (1-sqrtOneBeta2)/(4*oneBeta2_to_ 237 238 secondTerm = std::sqrt(1 - sqrtOneBeta2)/(st 239 (4*beta2/sqrtOneBeta2 * sinThet 240 - 4*(1-sqrtOneBeta2)/oneBeta2 * 241 + 4*beta2*(1-sqrtOneBeta2)/oneB 242 + (1-sqrtOneBeta2)/(4*beta2*one 243 (1-sqrtOneBeta2)/oneBeta2_to_3_ 244 245 dsigma = ( firstTerm*(1-pi*fine_structure_co 246 247 return dsigma; 248 } 249 250 // 251 252 G4double G4RDPhotoElectricAngularGeneratorPola 253 { 254 255 //Double differential L1 shell cross-section 256 257 G4double beta2 = beta*beta; 258 G4double oneBeta2 = 1-beta2; 259 G4double sqrtOneBeta2 = std::sqrt(oneBeta2); 260 G4double oneBeta2_to_3_2=std::pow(oneBeta2,1 261 G4double cosTheta = std::cos(theta); 262 G4double sinTheta2 =std::sin(theta)*std::sin 263 G4double cosPhi2 = std::cos(phi)*std::cos(ph 264 G4double oneBetaCosTheta = 1-beta*cosTheta; 265 266 G4double dsigma = 0; 267 G4double firstTerm = 0; 268 G4double secondTerm = 0; 269 270 firstTerm = sinTheta2*cosPhi2/std::pow(oneBe 271 * (sinTheta2 * cosPhi2)/std::po 272 (1-sqrtOneBeta2)/(4*oneBeta2_to_ 273 274 secondTerm = std::sqrt(1 - sqrtOneBeta2)/(st 275 (4*beta2/sqrtOneBeta2 * sinThet 276 - 4*(1-sqrtOneBeta2)/oneBeta2 * 277 + 4*beta2*(1-sqrtOneBeta2)/oneB 278 + (1-sqrtOneBeta2)/(4*beta2*one 279 (1-sqrtOneBeta2)/oneBeta2_to_3_ 280 281 dsigma = ( firstTerm*(1-pi*fine_structure_co 282 283 return dsigma; 284 } 285 286 G4double G4RDPhotoElectricAngularGeneratorPola 287 { 288 if (arg1 > arg2) 289 return arg1; 290 else 291 return arg2; 292 } 293 294 // 295 296 G4RotationMatrix G4RDPhotoElectricAngularGener 297 const G4ThreeVector 298 { 299 G4double mK = direction.mag(); 300 G4double mS = polarization.mag(); 301 G4ThreeVector polarization2 = polarization; 302 const G4double kTolerance = 1e-6; 303 304 if(!(polarization.isOrthogonal(direction,kTo 305 G4ThreeVector d0 = direction.unit(); 306 G4ThreeVector a1 = SetPerpendicularVector( 307 G4ThreeVector a0 = a1.unit(); 308 G4double rand1 = G4UniformRand(); 309 G4double angle = twopi*rand1; 310 G4ThreeVector b0 = d0.cross(a0); 311 G4ThreeVector c; 312 c.setX(std::cos(angle)*(a0.x())+std::sin(a 313 c.setY(std::cos(angle)*(a0.y())+std::sin(a 314 c.setZ(std::cos(angle)*(a0.z())+std::sin(a 315 polarization2 = c.unit(); 316 mS = polarization2.mag(); 317 }else 318 { 319 if ( polarization.howOrthogonal(directio 320 { 321 polarization2 = polarization - polarizatio 322 } 323 } 324 325 G4ThreeVector direction2 = direction/mK; 326 polarization2 = polarization2/mS; 327 328 G4ThreeVector y = direction2.cross(polarizat 329 330 G4RotationMatrix R(polarization2,y,direction 331 return R; 332 } 333 334 void G4RDPhotoElectricAngularGeneratorPolarize 335 { 336 // This member function finds for a given sh 337 338 G4double aBeta,cBeta; 339 G4double bMin,bStep; 340 G4int indexMax; 341 G4int level = shellLevel; 342 if(shellLevel > 1) level = 1; // protection 343 344 bMin = betaArray[0]; 345 bStep = betaArray[1]; 346 indexMax = (G4int)betaArray[2]; 347 const G4double kBias = 1e-9; 348 349 G4int k = (G4int)((beta-bMin+kBias)/bStep); 350 351 if(k < 0) 352 k = 0; 353 if(k > indexMax) 354 k = indexMax; 355 356 if(k == 0) 357 aBeta = GetMax(aMajorantSurfaceParameterTa 358 else if(k==indexMax) 359 aBeta = GetMax(aMajorantSurfaceParameterTa 360 else{ 361 aBeta = GetMax(aMajorantSurfaceParameterTa 362 aBeta = GetMax(aBeta,aMajorantSurfaceParam 363 } 364 365 if(k == 0) 366 cBeta = GetMax(cMajorantSurfaceParameterTa 367 else if(k == indexMax) 368 cBeta = GetMax(cMajorantSurfaceParameterTa 369 else{ 370 cBeta = GetMax(cMajorantSurfaceParameterTa 371 cBeta = GetMax(cBeta,cMajorantSurfaceParam 372 } 373 374 *majorantSurfaceParameterA = aBeta; 375 *majorantSurfaceParameterC = cBeta; 376 377 } 378 379 380 // 381 G4ThreeVector G4RDPhotoElectricAngularGenerato 382 { 383 384 //computes the photoelectron momentum unitar 385 G4double px = std::cos(phi)*std::sin(theta); 386 G4double py = std::sin(phi)*std::sin(theta); 387 G4double pz = std::cos(theta); 388 389 G4ThreeVector samplingDirection(px,py,pz); 390 391 G4ThreeVector outgoingDirection = rotation*s 392 return outgoingDirection; 393 } 394 395 // 396 397 void G4RDPhotoElectricAngularGeneratorPolarize 398 { 399 G4cout << "\n" << G4endl; 400 G4cout << "Polarized Photoelectric Angular G 401 G4cout << "PhotoElectric Electron Angular Ge 402 G4cout << "Includes polarization effects for 403 G4cout << "For higher shells the L1 cross-se 404 G4cout << "(see Physics Reference Manual) \n 405 } 406 407 G4ThreeVector G4RDPhotoElectricAngularGenerato 408 { 409 G4double dx = a.x(); 410 G4double dy = a.y(); 411 G4double dz = a.z(); 412 G4double x = dx < 0.0 ? -dx : dx; 413 G4double y = dy < 0.0 ? -dy : dy; 414 G4double z = dz < 0.0 ? -dz : dz; 415 if (x < y) { 416 return x < z ? G4ThreeVector(-dy,dx,0) : G 417 }else{ 418 return y < z ? G4ThreeVector(dz,0,-dx) : G 419 } 420 } 421