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00029 #include "G4RPGSigmaMinusInelastic.hh"
00030 #include "G4PhysicalConstants.hh"
00031 #include "G4SystemOfUnits.hh"
00032 #include "Randomize.hh"
00033
00034 G4HadFinalState*
00035 G4RPGSigmaMinusInelastic::ApplyYourself( const G4HadProjectile &aTrack,
00036 G4Nucleus &targetNucleus )
00037 {
00038 const G4HadProjectile *originalIncident = &aTrack;
00039 if (originalIncident->GetKineticEnergy()<= 0.1*MeV)
00040 {
00041 theParticleChange.SetStatusChange(isAlive);
00042 theParticleChange.SetEnergyChange(aTrack.GetKineticEnergy());
00043 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
00044 return &theParticleChange;
00045 }
00046
00047
00048
00049 G4DynamicParticle *originalTarget = targetNucleus.ReturnTargetParticle();
00050
00051 if( verboseLevel > 1 )
00052 {
00053 const G4Material *targetMaterial = aTrack.GetMaterial();
00054 G4cout << "G4RPGSigmaMinusInelastic::ApplyYourself called" << G4endl;
00055 G4cout << "kinetic energy = " << originalIncident->GetKineticEnergy()/MeV << "MeV, ";
00056 G4cout << "target material = " << targetMaterial->GetName() << ", ";
00057 G4cout << "target particle = " << originalTarget->GetDefinition()->GetParticleName()
00058 << G4endl;
00059 }
00060
00061
00062
00063
00064 G4double ek = originalIncident->GetKineticEnergy()/MeV;
00065 G4double amas = originalIncident->GetDefinition()->GetPDGMass()/MeV;
00066 G4ReactionProduct modifiedOriginal;
00067 modifiedOriginal = *originalIncident;
00068
00069 G4double tkin = targetNucleus.Cinema( ek );
00070 ek += tkin;
00071 modifiedOriginal.SetKineticEnergy( ek*MeV );
00072 G4double et = ek + amas;
00073 G4double p = std::sqrt( std::abs((et-amas)*(et+amas)) );
00074 G4double pp = modifiedOriginal.GetMomentum().mag()/MeV;
00075 if( pp > 0.0 )
00076 {
00077 G4ThreeVector momentum = modifiedOriginal.GetMomentum();
00078 modifiedOriginal.SetMomentum( momentum * (p/pp) );
00079 }
00080
00081
00082
00083 tkin = targetNucleus.EvaporationEffects( ek );
00084 ek -= tkin;
00085 modifiedOriginal.SetKineticEnergy( ek*MeV );
00086 et = ek + amas;
00087 p = std::sqrt( std::abs((et-amas)*(et+amas)) );
00088 pp = modifiedOriginal.GetMomentum().mag()/MeV;
00089 if( pp > 0.0 )
00090 {
00091 G4ThreeVector momentum = modifiedOriginal.GetMomentum();
00092 modifiedOriginal.SetMomentum( momentum * (p/pp) );
00093 }
00094 G4ReactionProduct currentParticle = modifiedOriginal;
00095 G4ReactionProduct targetParticle;
00096 targetParticle = *originalTarget;
00097 currentParticle.SetSide( 1 );
00098 targetParticle.SetSide( -1 );
00099 G4bool incidentHasChanged = false;
00100 G4bool targetHasChanged = false;
00101 G4bool quasiElastic = false;
00102 G4FastVector<G4ReactionProduct,GHADLISTSIZE> vec;
00103 G4int vecLen = 0;
00104 vec.Initialize( 0 );
00105
00106 const G4double cutOff = 0.1;
00107 if( originalIncident->GetKineticEnergy()/MeV > cutOff )
00108 Cascade( vec, vecLen,
00109 originalIncident, currentParticle, targetParticle,
00110 incidentHasChanged, targetHasChanged, quasiElastic );
00111
00112 CalculateMomenta( vec, vecLen,
00113 originalIncident, originalTarget, modifiedOriginal,
00114 targetNucleus, currentParticle, targetParticle,
00115 incidentHasChanged, targetHasChanged, quasiElastic );
00116
00117 SetUpChange( vec, vecLen,
00118 currentParticle, targetParticle,
00119 incidentHasChanged );
00120
00121 delete originalTarget;
00122 return &theParticleChange;
00123 }
00124
00125
00126 void G4RPGSigmaMinusInelastic::Cascade(
00127 G4FastVector<G4ReactionProduct,GHADLISTSIZE> &vec,
00128 G4int& vecLen,
00129 const G4HadProjectile *originalIncident,
00130 G4ReactionProduct ¤tParticle,
00131 G4ReactionProduct &targetParticle,
00132 G4bool &incidentHasChanged,
00133 G4bool &targetHasChanged,
00134 G4bool &quasiElastic )
00135 {
00136
00137
00138
00139
00140
00141
00142
00143
00144
00145
00146 const G4double mOriginal = originalIncident->GetDefinition()->GetPDGMass()/MeV;
00147 const G4double etOriginal = originalIncident->GetTotalEnergy()/MeV;
00148 const G4double targetMass = targetParticle.GetMass()/MeV;
00149 G4double centerofmassEnergy = std::sqrt( mOriginal*mOriginal +
00150 targetMass*targetMass +
00151 2.0*targetMass*etOriginal );
00152 G4double availableEnergy = centerofmassEnergy-(targetMass+mOriginal);
00153 if( availableEnergy <= G4PionPlus::PionPlus()->GetPDGMass()/MeV )
00154 {
00155 quasiElastic = true;
00156 return;
00157 }
00158 static G4bool first = true;
00159 const G4int numMul = 1200;
00160 const G4int numSec = 60;
00161 static G4double protmul[numMul], protnorm[numSec];
00162 static G4double neutmul[numMul], neutnorm[numSec];
00163
00164 G4int counter, nt=0, np=0, nneg=0, nz=0;
00165 G4double test;
00166 const G4double c = 1.25;
00167 const G4double b[] = { 0.70, 0.70 };
00168 if( first )
00169 {
00170 first = false;
00171 G4int i;
00172 for( i=0; i<numMul; ++i )protmul[i] = 0.0;
00173 for( i=0; i<numSec; ++i )protnorm[i] = 0.0;
00174 counter = -1;
00175 for( np=0; np<(numSec/3); ++np )
00176 {
00177 for( nneg=std::max(0,np-1); nneg<=(np+1); ++nneg )
00178 {
00179 for( nz=0; nz<numSec/3; ++nz )
00180 {
00181 if( ++counter < numMul )
00182 {
00183 nt = np+nneg+nz;
00184 if( nt>0 && nt<=numSec )
00185 {
00186 protmul[counter] = Pmltpc(np,nneg,nz,nt,b[0],c);
00187 protnorm[nt-1] += protmul[counter];
00188 }
00189 }
00190 }
00191 }
00192 }
00193 for( i=0; i<numMul; ++i )neutmul[i] = 0.0;
00194 for( i=0; i<numSec; ++i )neutnorm[i] = 0.0;
00195 counter = -1;
00196 for( np=0; np<numSec/3; ++np )
00197 {
00198 for( nneg=np; nneg<=(np+2); ++nneg )
00199 {
00200 for( nz=0; nz<numSec/3; ++nz )
00201 {
00202 if( ++counter < numMul )
00203 {
00204 nt = np+nneg+nz;
00205 if( nt>0 && nt<=numSec )
00206 {
00207 neutmul[counter] = Pmltpc(np,nneg,nz,nt,b[1],c);
00208 neutnorm[nt-1] += neutmul[counter];
00209 }
00210 }
00211 }
00212 }
00213 }
00214 for( i=0; i<numSec; ++i )
00215 {
00216 if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
00217 if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
00218 }
00219 }
00220
00221 const G4double expxu = 82.;
00222 const G4double expxl = -expxu;
00223 G4ParticleDefinition *aNeutron = G4Neutron::Neutron();
00224 G4ParticleDefinition *aProton = G4Proton::Proton();
00225 G4ParticleDefinition *aLambda = G4Lambda::Lambda();
00226 G4ParticleDefinition *aSigmaZero = G4SigmaZero::SigmaZero();
00227
00228
00229
00230 G4double n, anpn;
00231 GetNormalizationConstant( availableEnergy, n, anpn );
00232 G4double ran = G4UniformRand();
00233 G4double dum, excs = 0.0;
00234 if( targetParticle.GetDefinition() == aProton )
00235 {
00236 counter = -1;
00237 for( np=0; np<numSec/3 && ran>=excs; ++np )
00238 {
00239 for( nneg=std::max(0,np-1); nneg<=(np+1) && ran>=excs; ++nneg )
00240 {
00241 for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
00242 {
00243 if( ++counter < numMul )
00244 {
00245 nt = np+nneg+nz;
00246 if( nt>0 && nt<=numSec )
00247 {
00248 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
00249 dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
00250 if( std::fabs(dum) < 1.0 )
00251 {
00252 if( test >= 1.0e-10 )excs += dum*test;
00253 }
00254 else
00255 excs += dum*test;
00256 }
00257 }
00258 }
00259 }
00260 }
00261 if( ran >= excs )
00262 {
00263 quasiElastic = true;
00264 return;
00265 }
00266 np--; nneg--; nz--;
00267 G4int ncht = std::max( 1, np-nneg+2 );
00268 switch( ncht )
00269 {
00270 case 1:
00271 if( G4UniformRand() < 0.5 )
00272 currentParticle.SetDefinitionAndUpdateE( aLambda );
00273 else
00274 currentParticle.SetDefinitionAndUpdateE( aSigmaZero );
00275 incidentHasChanged = true;
00276 break;
00277 case 2:
00278 if( G4UniformRand() >= 0.5 )
00279 {
00280 if( G4UniformRand() < 0.5 )
00281 currentParticle.SetDefinitionAndUpdateE( aLambda );
00282 else
00283 currentParticle.SetDefinitionAndUpdateE( aSigmaZero );
00284 incidentHasChanged = true;
00285 targetParticle.SetDefinitionAndUpdateE( aNeutron );
00286 targetHasChanged = true;
00287 }
00288 break;
00289 default:
00290 targetParticle.SetDefinitionAndUpdateE( aNeutron );
00291 targetHasChanged = true;
00292 break;
00293 }
00294 }
00295 else
00296 {
00297 counter = -1;
00298 for( np=0; np<numSec/3 && ran>=excs; ++np )
00299 {
00300 for( nneg=np; nneg<=(np+2) && ran>=excs; ++nneg )
00301 {
00302 for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
00303 {
00304 if( ++counter < numMul )
00305 {
00306 nt = np+nneg+nz;
00307 if( nt>0 && nt<=numSec )
00308 {
00309 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
00310 dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
00311 if( std::fabs(dum) < 1.0 )
00312 {
00313 if( test >= 1.0e-10 )excs += dum*test;
00314 }
00315 else
00316 excs += dum*test;
00317 }
00318 }
00319 }
00320 }
00321 }
00322 if( ran >= excs )
00323 {
00324 quasiElastic = true;
00325 return;
00326 }
00327 np--; nneg--; nz--;
00328 G4int ncht = std::max( 1, np-nneg+3 );
00329 switch( ncht )
00330 {
00331 case 1:
00332 if( G4UniformRand() < 0.5 )
00333 currentParticle.SetDefinitionAndUpdateE( aLambda );
00334 else
00335 currentParticle.SetDefinitionAndUpdateE( aSigmaZero );
00336 incidentHasChanged = true;
00337 targetParticle.SetDefinitionAndUpdateE( aProton );
00338 targetHasChanged = true;
00339 break;
00340 case 2:
00341 if( G4UniformRand() < 0.5 )
00342 {
00343 if( G4UniformRand() < 0.5 )
00344 currentParticle.SetDefinitionAndUpdateE( aLambda );
00345 else
00346 currentParticle.SetDefinitionAndUpdateE( aSigmaZero );
00347 incidentHasChanged = true;
00348 }
00349 else
00350 {
00351 targetParticle.SetDefinitionAndUpdateE( aProton );
00352 targetHasChanged = true;
00353 }
00354 break;
00355 default:
00356 break;
00357 }
00358 }
00359
00360 SetUpPions(np, nneg, nz, vec, vecLen);
00361 return;
00362 }
00363
00364
00365