[819] | 1 | // |
---|
| 2 | // ******************************************************************** |
---|
| 3 | // * License and Disclaimer * |
---|
| 4 | // * * |
---|
| 5 | // * The Geant4 software is copyright of the Copyright Holders of * |
---|
| 6 | // * the Geant4 Collaboration. It is provided under the terms and * |
---|
| 7 | // * conditions of the Geant4 Software License, included in the file * |
---|
| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
---|
| 9 | // * include a list of copyright holders. * |
---|
| 10 | // * * |
---|
| 11 | // * Neither the authors of this software system, nor their employing * |
---|
| 12 | // * institutes,nor the agencies providing financial support for this * |
---|
| 13 | // * work make any representation or warranty, express or implied, * |
---|
| 14 | // * regarding this software system or assume any liability for its * |
---|
| 15 | // * use. Please see the license in the file LICENSE and URL above * |
---|
| 16 | // * for the full disclaimer and the limitation of liability. * |
---|
| 17 | // * * |
---|
| 18 | // * This code implementation is the result of the scientific and * |
---|
| 19 | // * technical work of the GEANT4 collaboration. * |
---|
| 20 | // * By using, copying, modifying or distributing the software (or * |
---|
| 21 | // * any work based on the software) you agree to acknowledge its * |
---|
| 22 | // * use in resulting scientific publications, and indicate your * |
---|
| 23 | // * acceptance of all terms of the Geant4 Software license. * |
---|
| 24 | // ******************************************************************** |
---|
| 25 | // |
---|
| 26 | // |
---|
| 27 | // $Id: G4LESigmaPlusInelastic.cc,v 1.11 2006/06/29 20:45:19 gunter Exp $ |
---|
[1228] | 28 | // GEANT4 tag $Name: geant4-09-03 $ |
---|
[819] | 29 | // |
---|
| 30 | // Hadronic Process: SigmaPlus Inelastic Process |
---|
| 31 | // J.L. Chuma, TRIUMF, 19-Feb-1997 |
---|
| 32 | // Last modified: 27-Mar-1997 |
---|
| 33 | // Modified by J.L.Chuma 30-Apr-97: added originalTarget for CalculateMomenta |
---|
| 34 | |
---|
| 35 | #include "G4LESigmaPlusInelastic.hh" |
---|
| 36 | #include "Randomize.hh" |
---|
| 37 | |
---|
| 38 | G4HadFinalState * |
---|
| 39 | G4LESigmaPlusInelastic::ApplyYourself( const G4HadProjectile &aTrack, |
---|
| 40 | G4Nucleus &targetNucleus ) |
---|
| 41 | { |
---|
| 42 | const G4HadProjectile *originalIncident = &aTrack; |
---|
| 43 | if (originalIncident->GetKineticEnergy()<= 0.1*MeV) |
---|
| 44 | { |
---|
| 45 | theParticleChange.SetStatusChange(isAlive); |
---|
| 46 | theParticleChange.SetEnergyChange(aTrack.GetKineticEnergy()); |
---|
| 47 | theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit()); |
---|
| 48 | return &theParticleChange; |
---|
| 49 | } |
---|
| 50 | // |
---|
| 51 | // create the target particle |
---|
| 52 | // |
---|
| 53 | G4DynamicParticle *originalTarget = targetNucleus.ReturnTargetParticle(); |
---|
| 54 | |
---|
| 55 | if( verboseLevel > 1 ) |
---|
| 56 | { |
---|
| 57 | const G4Material *targetMaterial = aTrack.GetMaterial(); |
---|
| 58 | G4cout << "G4LESigmaPlusInelastic::ApplyYourself called" << G4endl; |
---|
| 59 | G4cout << "kinetic energy = " << originalIncident->GetKineticEnergy()/MeV << "MeV, "; |
---|
| 60 | G4cout << "target material = " << targetMaterial->GetName() << ", "; |
---|
| 61 | G4cout << "target particle = " << originalTarget->GetDefinition()->GetParticleName() |
---|
| 62 | << G4endl; |
---|
| 63 | } |
---|
| 64 | // |
---|
| 65 | // Fermi motion and evaporation |
---|
| 66 | // As of Geant3, the Fermi energy calculation had not been Done |
---|
| 67 | // |
---|
| 68 | G4double ek = originalIncident->GetKineticEnergy()/MeV; |
---|
| 69 | G4double amas = originalIncident->GetDefinition()->GetPDGMass()/MeV; |
---|
| 70 | G4ReactionProduct modifiedOriginal; |
---|
| 71 | modifiedOriginal = *originalIncident; |
---|
| 72 | |
---|
| 73 | G4double tkin = targetNucleus.Cinema( ek ); |
---|
| 74 | ek += tkin; |
---|
| 75 | modifiedOriginal.SetKineticEnergy( ek*MeV ); |
---|
| 76 | G4double et = ek + amas; |
---|
| 77 | G4double p = std::sqrt( std::abs((et-amas)*(et+amas)) ); |
---|
| 78 | G4double pp = modifiedOriginal.GetMomentum().mag()/MeV; |
---|
| 79 | if( pp > 0.0 ) |
---|
| 80 | { |
---|
| 81 | G4ThreeVector momentum = modifiedOriginal.GetMomentum(); |
---|
| 82 | modifiedOriginal.SetMomentum( momentum * (p/pp) ); |
---|
| 83 | } |
---|
| 84 | // |
---|
| 85 | // calculate black track energies |
---|
| 86 | // |
---|
| 87 | tkin = targetNucleus.EvaporationEffects( ek ); |
---|
| 88 | ek -= tkin; |
---|
| 89 | modifiedOriginal.SetKineticEnergy( ek*MeV ); |
---|
| 90 | et = ek + amas; |
---|
| 91 | p = std::sqrt( std::abs((et-amas)*(et+amas)) ); |
---|
| 92 | pp = modifiedOriginal.GetMomentum().mag()/MeV; |
---|
| 93 | if( pp > 0.0 ) |
---|
| 94 | { |
---|
| 95 | G4ThreeVector momentum = modifiedOriginal.GetMomentum(); |
---|
| 96 | modifiedOriginal.SetMomentum( momentum * (p/pp) ); |
---|
| 97 | } |
---|
| 98 | G4ReactionProduct currentParticle = modifiedOriginal; |
---|
| 99 | G4ReactionProduct targetParticle; |
---|
| 100 | targetParticle = *originalTarget; |
---|
| 101 | currentParticle.SetSide( 1 ); // incident always goes in forward hemisphere |
---|
| 102 | targetParticle.SetSide( -1 ); // target always goes in backward hemisphere |
---|
| 103 | G4bool incidentHasChanged = false; |
---|
| 104 | G4bool targetHasChanged = false; |
---|
| 105 | G4bool quasiElastic = false; |
---|
| 106 | G4FastVector<G4ReactionProduct,GHADLISTSIZE> vec; // vec will contain the secondary particles |
---|
| 107 | G4int vecLen = 0; |
---|
| 108 | vec.Initialize( 0 ); |
---|
| 109 | |
---|
| 110 | const G4double cutOff = 0.1; |
---|
| 111 | if( currentParticle.GetKineticEnergy()/MeV > cutOff ) |
---|
| 112 | Cascade( vec, vecLen, |
---|
| 113 | originalIncident, currentParticle, targetParticle, |
---|
| 114 | incidentHasChanged, targetHasChanged, quasiElastic ); |
---|
| 115 | |
---|
| 116 | CalculateMomenta( vec, vecLen, |
---|
| 117 | originalIncident, originalTarget, modifiedOriginal, |
---|
| 118 | targetNucleus, currentParticle, targetParticle, |
---|
| 119 | incidentHasChanged, targetHasChanged, quasiElastic ); |
---|
| 120 | |
---|
| 121 | SetUpChange( vec, vecLen, |
---|
| 122 | currentParticle, targetParticle, |
---|
| 123 | incidentHasChanged ); |
---|
| 124 | |
---|
| 125 | delete originalTarget; |
---|
| 126 | return &theParticleChange; |
---|
| 127 | } |
---|
| 128 | |
---|
| 129 | void |
---|
| 130 | G4LESigmaPlusInelastic::Cascade( |
---|
| 131 | G4FastVector<G4ReactionProduct,GHADLISTSIZE> &vec, |
---|
| 132 | G4int& vecLen, |
---|
| 133 | const G4HadProjectile *originalIncident, |
---|
| 134 | G4ReactionProduct ¤tParticle, |
---|
| 135 | G4ReactionProduct &targetParticle, |
---|
| 136 | G4bool &incidentHasChanged, |
---|
| 137 | G4bool &targetHasChanged, |
---|
| 138 | G4bool &quasiElastic ) |
---|
| 139 | { |
---|
| 140 | // derived from original FORTRAN code CASSP by H. Fesefeldt (30-Nov-1987) |
---|
| 141 | // |
---|
| 142 | // SigmaPlus undergoes interaction with nucleon within a nucleus. Check if it is |
---|
| 143 | // energetically possible to produce pions/kaons. In not, assume nuclear excitation |
---|
| 144 | // occurs and input particle is degraded in energy. No other particles are produced. |
---|
| 145 | // If reaction is possible, find the correct number of pions/protons/neutrons |
---|
| 146 | // produced using an interpolation to multiplicity data. Replace some pions or |
---|
| 147 | // protons/neutrons by kaons or strange baryons according to the average |
---|
| 148 | // multiplicity per inelastic reaction. |
---|
| 149 | // |
---|
| 150 | const G4double mOriginal = originalIncident->GetDefinition()->GetPDGMass()/MeV; |
---|
| 151 | const G4double etOriginal = originalIncident->GetTotalEnergy()/MeV; |
---|
| 152 | const G4double targetMass = targetParticle.GetMass()/MeV; |
---|
| 153 | G4double centerofmassEnergy = std::sqrt( mOriginal*mOriginal + |
---|
| 154 | targetMass*targetMass + |
---|
| 155 | 2.0*targetMass*etOriginal ); |
---|
| 156 | G4double availableEnergy = centerofmassEnergy-(targetMass+mOriginal); |
---|
| 157 | if( availableEnergy <= G4PionPlus::PionPlus()->GetPDGMass()/MeV ) |
---|
| 158 | { |
---|
| 159 | quasiElastic = true; |
---|
| 160 | return; |
---|
| 161 | } |
---|
| 162 | static G4bool first = true; |
---|
| 163 | const G4int numMul = 1200; |
---|
| 164 | const G4int numSec = 60; |
---|
| 165 | static G4double protmul[numMul], protnorm[numSec]; // proton constants |
---|
| 166 | static G4double neutmul[numMul], neutnorm[numSec]; // neutron constants |
---|
| 167 | // np = number of pi+, nm = number of pi-, nz = number of pi0 |
---|
| 168 | G4int counter, nt=0, np=0, nm=0, nz=0; |
---|
| 169 | G4double test; |
---|
| 170 | const G4double c = 1.25; |
---|
| 171 | const G4double b[] = { 0.7, 0.7 }; |
---|
| 172 | if( first ) // compute normalization constants, this will only be Done once |
---|
| 173 | { |
---|
| 174 | first = false; |
---|
| 175 | G4int i; |
---|
| 176 | for( i=0; i<numMul; ++i )protmul[i] = 0.0; |
---|
| 177 | for( i=0; i<numSec; ++i )protnorm[i] = 0.0; |
---|
| 178 | counter = -1; |
---|
| 179 | for( np=0; np<(numSec/3); ++np ) |
---|
| 180 | { |
---|
| 181 | for( nm=np; nm<=(np+2); ++nm ) |
---|
| 182 | { |
---|
| 183 | for( nz=0; nz<numSec/3; ++nz ) |
---|
| 184 | { |
---|
| 185 | if( ++counter < numMul ) |
---|
| 186 | { |
---|
| 187 | nt = np+nm+nz; |
---|
| 188 | if( nt>0 && nt<=numSec ) |
---|
| 189 | { |
---|
| 190 | protmul[counter] = Pmltpc(np,nm,nz,nt,b[0],c); |
---|
| 191 | protnorm[nt-1] += protmul[counter]; |
---|
| 192 | } |
---|
| 193 | } |
---|
| 194 | } |
---|
| 195 | } |
---|
| 196 | } |
---|
| 197 | for( i=0; i<numMul; ++i )neutmul[i] = 0.0; |
---|
| 198 | for( i=0; i<numSec; ++i )neutnorm[i] = 0.0; |
---|
| 199 | counter = -1; |
---|
| 200 | for( np=0; np<numSec/3; ++np ) |
---|
| 201 | { |
---|
| 202 | for( nm=std::max(0,np-1); nm<=(np+1); ++nm ) |
---|
| 203 | { |
---|
| 204 | for( nz=0; nz<numSec/3; ++nz ) |
---|
| 205 | { |
---|
| 206 | if( ++counter < numMul ) |
---|
| 207 | { |
---|
| 208 | nt = np+nm+nz; |
---|
| 209 | if( nt>0 && nt<=numSec ) |
---|
| 210 | { |
---|
| 211 | neutmul[counter] = Pmltpc(np,nm,nz,nt,b[1],c); |
---|
| 212 | neutnorm[nt-1] += neutmul[counter]; |
---|
| 213 | } |
---|
| 214 | } |
---|
| 215 | } |
---|
| 216 | } |
---|
| 217 | } |
---|
| 218 | for( i=0; i<numSec; ++i ) |
---|
| 219 | { |
---|
| 220 | if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i]; |
---|
| 221 | if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i]; |
---|
| 222 | } |
---|
| 223 | } // end of initialization |
---|
| 224 | |
---|
| 225 | const G4double expxu = 82.; // upper bound for arg. of exp |
---|
| 226 | const G4double expxl = -expxu; // lower bound for arg. of exp |
---|
| 227 | G4ParticleDefinition *aNeutron = G4Neutron::Neutron(); |
---|
| 228 | G4ParticleDefinition *aProton = G4Proton::Proton(); |
---|
| 229 | G4ParticleDefinition *aLambda = G4Lambda::Lambda(); |
---|
| 230 | G4ParticleDefinition *aSigmaZero = G4SigmaZero::SigmaZero(); |
---|
| 231 | // |
---|
| 232 | // energetically possible to produce pion(s) --> inelastic scattering |
---|
| 233 | // |
---|
| 234 | G4double n, anpn; |
---|
| 235 | GetNormalizationConstant( availableEnergy, n, anpn ); |
---|
| 236 | G4double ran = G4UniformRand(); |
---|
| 237 | G4double dum, excs = 0.0; |
---|
| 238 | if( targetParticle.GetDefinition() == aProton ) |
---|
| 239 | { |
---|
| 240 | counter = -1; |
---|
| 241 | for( np=0; np<numSec/3 && ran>=excs; ++np ) |
---|
| 242 | { |
---|
| 243 | for( nm=np; nm<=(np+2) && ran>=excs; ++nm ) |
---|
| 244 | { |
---|
| 245 | for( nz=0; nz<numSec/3 && ran>=excs; ++nz ) |
---|
| 246 | { |
---|
| 247 | if( ++counter < numMul ) |
---|
| 248 | { |
---|
| 249 | nt = np+nm+nz; |
---|
| 250 | if( nt>0 && nt<=numSec ) |
---|
| 251 | { |
---|
| 252 | test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) ); |
---|
| 253 | dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n); |
---|
| 254 | if( std::fabs(dum) < 1.0 ) |
---|
| 255 | { |
---|
| 256 | if( test >= 1.0e-10 )excs += dum*test; |
---|
| 257 | } |
---|
| 258 | else |
---|
| 259 | excs += dum*test; |
---|
| 260 | } |
---|
| 261 | } |
---|
| 262 | } |
---|
| 263 | } |
---|
| 264 | } |
---|
| 265 | if( ran >= excs ) // 3 previous loops continued to the end |
---|
| 266 | { |
---|
| 267 | quasiElastic = true; |
---|
| 268 | return; |
---|
| 269 | } |
---|
| 270 | np--; nm--; nz--; |
---|
| 271 | switch( std::min( 3, std::max( 1, np-nm+3 ) ) ) |
---|
| 272 | { |
---|
| 273 | case 1: |
---|
| 274 | if( G4UniformRand() < 0.5 ) |
---|
| 275 | currentParticle.SetDefinitionAndUpdateE( aLambda ); |
---|
| 276 | else |
---|
| 277 | currentParticle.SetDefinitionAndUpdateE( aSigmaZero ); |
---|
| 278 | incidentHasChanged = true; |
---|
| 279 | targetParticle.SetDefinitionAndUpdateE( aNeutron ); |
---|
| 280 | targetHasChanged = true; |
---|
| 281 | break; |
---|
| 282 | case 2: |
---|
| 283 | if( G4UniformRand() < 0.5 ) |
---|
| 284 | { |
---|
| 285 | targetParticle.SetDefinitionAndUpdateE( aNeutron ); |
---|
| 286 | targetHasChanged = true; |
---|
| 287 | } |
---|
| 288 | else |
---|
| 289 | { |
---|
| 290 | if( G4UniformRand() < 0.5 ) |
---|
| 291 | currentParticle.SetDefinitionAndUpdateE( aLambda ); |
---|
| 292 | else |
---|
| 293 | currentParticle.SetDefinitionAndUpdateE( aSigmaZero ); |
---|
| 294 | incidentHasChanged = true; |
---|
| 295 | } |
---|
| 296 | break; |
---|
| 297 | case 3: |
---|
| 298 | break; |
---|
| 299 | } |
---|
| 300 | } |
---|
| 301 | else // target must be a neutron |
---|
| 302 | { |
---|
| 303 | counter = -1; |
---|
| 304 | for( np=0; np<numSec/3 && ran>=excs; ++np ) |
---|
| 305 | { |
---|
| 306 | for( nm=std::max(0,np-1); nm<=(np+1) && ran>=excs; ++nm ) |
---|
| 307 | { |
---|
| 308 | for( nz=0; nz<numSec/3 && ran>=excs; ++nz ) |
---|
| 309 | { |
---|
| 310 | if( ++counter < numMul ) |
---|
| 311 | { |
---|
| 312 | nt = np+nm+nz; |
---|
| 313 | if( nt>0 && nt<=numSec ) |
---|
| 314 | { |
---|
| 315 | test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) ); |
---|
| 316 | dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n); |
---|
| 317 | if( std::fabs(dum) < 1.0 ) |
---|
| 318 | { |
---|
| 319 | if( test >= 1.0e-10 )excs += dum*test; |
---|
| 320 | } |
---|
| 321 | else |
---|
| 322 | excs += dum*test; |
---|
| 323 | } |
---|
| 324 | } |
---|
| 325 | } |
---|
| 326 | } |
---|
| 327 | } |
---|
| 328 | if( ran >= excs ) // 3 previous loops continued to the end |
---|
| 329 | { |
---|
| 330 | quasiElastic = true; |
---|
| 331 | return; |
---|
| 332 | } |
---|
| 333 | np--; nm--; nz--; |
---|
| 334 | switch( std::min( 3, std::max( 1, np-nm+2 ) ) ) |
---|
| 335 | { |
---|
| 336 | case 1: |
---|
| 337 | targetParticle.SetDefinitionAndUpdateE( aProton ); |
---|
| 338 | targetHasChanged = true; |
---|
| 339 | break; |
---|
| 340 | case 2: |
---|
| 341 | if( G4UniformRand() < 0.5 ) |
---|
| 342 | { |
---|
| 343 | if( G4UniformRand() < 0.5 ) |
---|
| 344 | { |
---|
| 345 | currentParticle.SetDefinitionAndUpdateE( aLambda ); |
---|
| 346 | incidentHasChanged = true; |
---|
| 347 | targetParticle.SetDefinitionAndUpdateE( aProton ); |
---|
| 348 | targetHasChanged = true; |
---|
| 349 | } |
---|
| 350 | else |
---|
| 351 | { |
---|
| 352 | targetParticle.SetDefinitionAndUpdateE( aNeutron ); |
---|
| 353 | targetHasChanged = true; |
---|
| 354 | } |
---|
| 355 | } |
---|
| 356 | else |
---|
| 357 | { |
---|
| 358 | if( G4UniformRand() < 0.5 ) |
---|
| 359 | { |
---|
| 360 | currentParticle.SetDefinitionAndUpdateE( aSigmaZero ); |
---|
| 361 | incidentHasChanged = true; |
---|
| 362 | targetParticle.SetDefinitionAndUpdateE( aProton ); |
---|
| 363 | targetHasChanged = true; |
---|
| 364 | } |
---|
| 365 | } |
---|
| 366 | break; |
---|
| 367 | case 3: |
---|
| 368 | if( G4UniformRand() < 0.5 ) |
---|
| 369 | currentParticle.SetDefinitionAndUpdateE( aLambda ); |
---|
| 370 | else |
---|
| 371 | currentParticle.SetDefinitionAndUpdateE( aSigmaZero ); |
---|
| 372 | incidentHasChanged = true; |
---|
| 373 | break; |
---|
| 374 | } |
---|
| 375 | } |
---|
| 376 | SetUpPions( np, nm, nz, vec, vecLen ); |
---|
| 377 | return; |
---|
| 378 | } |
---|
| 379 | |
---|
| 380 | /* end of file */ |
---|
| 381 | |
---|