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216a75eeb1c9d83bd2f8d612fe761690fa561bba
geant4/source/processes/hadronic/models/abrasion/src/G4WilsonAbrasionModel.cc
T
Gabriele Cosmo 216a75eeb1 Import Geant4 8.1.0 source tree
2016-06-09 14:44:26 +02:00

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//
// ********************************************************************
// * License and Disclaimer *
// * *
// * The Geant4 software is copyright of the Copyright Holders of *
// * the Geant4 Collaboration. It is provided under the terms and *
// * conditions of the Geant4 Software License, included in the file *
// * LICENSE and available at http://cern.ch/geant4/license . These *
// * include a list of copyright holders. *
// * *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work make any representation or warranty, express or implied, *
// * regarding this software system or assume any liability for its *
// * use. Please see the license in the file LICENSE and URL above *
// * for the full disclaimer and the limitation of liability. *
// * *
// * This code implementation is the result of the scientific and *
// * technical work of the GEANT4 collaboration. *
// * *
// * Parts of this code which have been developed by QinetiQ Ltd *
// * under contract to the European Space Agency (ESA) are the *
// * intellectual property of ESA. Rights to use, copy, modify and *
// * redistribute this software for general public use are granted *
// * in compliance with any licensing, distribution and development *
// * policy adopted by the Geant4 Collaboration. This code has been *
// * written by QinetiQ Ltd for the European Space Agency, under ESA *
// * contract 17191/03/NL/LvH (Aurora Programme). *
// * *
// * By using, copying, modifying or distributing the software (or *
// * any work based on the software) you agree to acknowledge its *
// * use in resulting scientific publications, and indicate your *
// * acceptance of all terms of the Geant4 Software license. *
// ********************************************************************
//
// %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//
// MODULE: G4WilsonAbrasionModel.cc
//
// Version: B.2
// Date: 18/01/05
// Author: P R Truscott
// Organisation: QinetiQ Ltd, UK
// Customer: ESA/ESTEC, NOORDWIJK
// Contract: 17191/03/NL/LvH
//
// %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//
// CHANGE HISTORY
// --------------
//
// 6 October 2003, P R Truscott, QinetiQ Ltd, UK
// Created.
//
// 15 March 2004, P R Truscott, QinetiQ Ltd, UK
// Beta release
//
// 18 January 2005, M H Mendenhall, Vanderbilt University, US
// Pointers to theAbrasionGeometry and products generated by the deexcitation
// handler deleted to prevent memory leaks. Also particle change of projectile
// fragment previously not properly defined.
//
// %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
////////////////////////////////////////////////////////////////////////////////
//
#include "G4WilsonAbrasionModel.hh"
#include "G4WilsonRadius.hh"
#include "G4NuclearAbrasionGeometry.hh"
#include "G4WilsonAblationModel.hh"
#include "G4ExcitationHandler.hh"
#include "G4Evaporation.hh"
#include "G4FermiBreakUp.hh"
#include "G4StatMF.hh"
#include "G4ParticleDefinition.hh"
#include "G4DynamicParticle.hh"
#include "Randomize.hh"
#include "G4Fragment.hh"
#include "G4VNuclearDensity.hh"
#include "G4NuclearShellModelDensity.hh"
#include "G4NuclearFermiDensity.hh"
#include "G4FermiMomentum.hh"
#include "G4ReactionProductVector.hh"
#include "G4LorentzVector.hh"
#include "G4ParticleMomentum.hh"
#include "G4Poisson.hh"
#include "G4ParticleTable.hh"
#include "G4IonTable.hh"
#include "globals.hh"
////////////////////////////////////////////////////////////////////////////////
//
G4WilsonAbrasionModel::G4WilsonAbrasionModel (G4bool useAblation1)
{
//
//
// Send message to stdout to advise that the G4Abrasion model is being used.
//
PrintWelcomeMessage();
//
//
// Set the default verbose level to 0 - no output.
//
verboseLevel = 0;
useAblation = useAblation1;
//
//
// No de-excitation handler has been supplied - define the default handler.
//
theExcitationHandler = new G4ExcitationHandler;
theExcitationHandlerx = new G4ExcitationHandler;
if (useAblation)
{
theAblation = new G4WilsonAblationModel;
theAblation->SetVerboseLevel(verboseLevel);
theExcitationHandler->SetEvaporation(theAblation);
theExcitationHandlerx->SetEvaporation(theAblation);
}
else
{
theAblation = NULL;
G4Evaporation * theEvaporation = new G4Evaporation;
G4FermiBreakUp * theFermiBreakUp = new G4FermiBreakUp;
G4StatMF * theMF = new G4StatMF;
theExcitationHandler->SetEvaporation(theEvaporation);
theExcitationHandler->SetFermiModel(theFermiBreakUp);
theExcitationHandler->SetMultiFragmentation(theMF);
theExcitationHandler->SetMaxAandZForFermiBreakUp(12, 6);
theExcitationHandler->SetMinEForMultiFrag(5.0*MeV);
theEvaporation = new G4Evaporation;
theFermiBreakUp = new G4FermiBreakUp;
theExcitationHandlerx->SetEvaporation(theEvaporation);
theExcitationHandlerx->SetFermiModel(theFermiBreakUp);
theExcitationHandlerx->SetMaxAandZForFermiBreakUp(12, 6);
}
//
//
// Set the minimum and maximum range for the model (despite nomanclature, this
// is in energy per nucleon number).
//
SetMinEnergy(70.0*MeV);
SetMaxEnergy(10.1*GeV);
isBlocked = false;
//
//
// npK, when mutiplied by the nuclear Fermi momentum, determines the range of
// momentum over which the secondary nucleon momentum is sampled.
//
npK = 5.0;
B = 10.0 * MeV;
third = 1.0 / 3.0;
conserveEnergy = false;
conserveMomentum = true;
}
////////////////////////////////////////////////////////////////////////////////
//
G4WilsonAbrasionModel::G4WilsonAbrasionModel (G4ExcitationHandler *aExcitationHandler)
{
//
//
// Send message to stdout to advise that the G4Abrasion model is being used.
//
PrintWelcomeMessage();
//
//
// Set the default verbose level to 0 - no output.
//
verboseLevel = 0;
//
//
// The user is able to provide the excitation handler as well as an argument
// which is provided in this instantiation is used to determine
// whether the spectators of the interaction are free following the abrasion.
//
theExcitationHandler = aExcitationHandler;
theExcitationHandlerx = new G4ExcitationHandler;
G4Evaporation * theEvaporation = new G4Evaporation;
G4FermiBreakUp * theFermiBreakUp = new G4FermiBreakUp;
theExcitationHandlerx->SetEvaporation(theEvaporation);
theExcitationHandlerx->SetFermiModel(theFermiBreakUp);
theExcitationHandlerx->SetMaxAandZForFermiBreakUp(12, 6);
//
//
// Set the minimum and maximum range for the model (despite nomanclature, this
// is in energy per nucleon number).
//
SetMinEnergy(70.0*MeV);
SetMaxEnergy(10.1*GeV);
isBlocked = false;
//
//
// npK, when mutiplied by the nuclear Fermi momentum, determines the range of
// momentum over which the secondary nucleon momentum is sampled.
//
npK = 5.0;
B = 10.0 * MeV;
third = 1.0 / 3.0;
conserveEnergy = false;
conserveMomentum = true;
}
////////////////////////////////////////////////////////////////////////////////
//
G4WilsonAbrasionModel::~G4WilsonAbrasionModel ()
{
//
//
// The destructor doesn't have to do a great deal!
//
delete theExcitationHandler;
delete theExcitationHandlerx;
}
////////////////////////////////////////////////////////////////////////////////
//
G4HadFinalState *G4WilsonAbrasionModel::ApplyYourself (
const G4HadProjectile &theTrack, G4Nucleus &theTarget)
{
//
//
// The secondaries will be returned in G4HadFinalState &theParticleChange -
// initialise this. The original track will always be discontinued and
// secondaries followed.
//
theParticleChange.Clear();
theParticleChange.SetStatusChange(stopAndKill);
//
//
// Get relevant information about the projectile and target (A, Z, energy/nuc,
// momentum, etc).
//
const G4ParticleDefinition *definitionP = theTrack.GetDefinition();
const G4double AP = definitionP->GetBaryonNumber();
const G4double ZP = definitionP->GetPDGCharge();
G4LorentzVector pP = theTrack.Get4Momentum();
G4double E = theTrack.GetKineticEnergy()/AP;
G4double AT = theTarget.GetN();
G4double ZT = theTarget.GetZ();
G4double TotalEPre = theTrack.GetTotalEnergy() +
theTarget.AtomicMass(AT, ZT) + theTarget.GetEnergyDeposit();
G4double TotalEPost = 0.0;
//
//
// Determine the radii of the projectile and target nuclei.
//
G4WilsonRadius aR;
G4double rP = aR.GetWilsonRadius(AP);
G4double rT = aR.GetWilsonRadius(AT);
G4double rPsq = rP * rP;
G4double rTsq = rT * rT;
if (verboseLevel >= 2)
{
G4cout <<"########################################"
<<"########################################"
<<G4endl;
G4cout.precision(6);
G4cout <<"IN G4WilsonAbrasionModel" <<G4endl;
G4cout <<"Initial projectile A=" <<AP
<<", Z=" <<ZP
<<", radius = " <<rP/fermi <<" fm"
<<G4endl;
G4cout <<"Initial target A=" <<AT
<<", Z=" <<ZT
<<", radius = " <<rT/fermi <<" fm"
<<G4endl;
G4cout <<"Projectile momentum and Energy/nuc = " <<pP <<" ," <<E <<G4endl;
}
//
//
// The following variables are used to determine the impact parameter in the
// near-field (i.e. taking into consideration the electrostatic repulsion).
//
G4double rm = ZP * ZT * elm_coupling / (E * AP);
G4double r = 0.0;
G4double rsq = 0.0;
//
//
// Initialise some of the variables which wll be used to calculate the chord-
// length for nucleons in the projectile and target, and hence calculate the
// number of abraded nucleons and the excitation energy.
//
G4NuclearAbrasionGeometry *theAbrasionGeometry = NULL;
G4double CT = 0.0;
G4double F = 0.0;
G4int Dabr = 0;
//
//
// The following loop is performed until the number of nucleons which are
// abraded by the process is >1, i.e. an interaction MUST occur.
//
while (Dabr == 0)
{
// Added by MHM 20050119 to fix leaking memory on second pass through this loop
if (theAbrasionGeometry)
{
delete theAbrasionGeometry;
theAbrasionGeometry = NULL;
}
//
//
// Sample the impact parameter. For the moment, this class takes account of
// electrostatic effects on the impact parameter, but (like HZETRN AND NUCFRG2)
// does not make any correction for the effects of nuclear-nuclear repulsion.
//
G4double rPT = rP + rT;
G4double rPTsq = rPT * rPT;
r = 1.1 * rPT;
while (r > rPT)
{
G4double bsq = rPTsq * G4UniformRand();
r = (rm + std::sqrt(rm*rm + 4.0*bsq)) / 2.0;
}
rsq = r * r;
//
//
// Now determine the chord-length through the target nucleus.
//
if (rT > rP)
{
G4double x = (rPsq + rsq - rTsq) / 2.0 / r;
if (x > 0.0) CT = 2.0 * std::sqrt(rTsq - x*x);
else CT = 2.0 * std::sqrt(rTsq - rsq);
}
else
{
G4double x = (rTsq + rsq - rPsq) / 2.0 / r;
if (x > 0.0) CT = 2.0 * std::sqrt(rTsq - x*x);
else CT = 2.0 * rT;
}
//
//
// Determine the number of abraded nucleons. Note that the mean number of
// abraded nucleons is used to sample the Poisson distribution. The Poisson
// distribution is sampled only ten times with the current impact parameter,
// and if it fails after this to find a case for which the number of abraded
// nucleons >1, the impact parameter is re-sampled.
//
theAbrasionGeometry = new G4NuclearAbrasionGeometry(AP,AT,r);
F = theAbrasionGeometry->F();
G4double lambda = 16.6*fermi / std::pow(E/MeV,0.26);
G4double Mabr = F * AP * (1.0 - std::exp(-CT/lambda));
G4long n = 0;
for (G4int i = 0; i<10; i++)
{
n = G4Poisson(Mabr);
if (n > 0)
{
if (n>AP) Dabr = (G4int) AP;
else Dabr = (G4int) n;
break;
}
}
}
if (verboseLevel >= 2)
{
G4cout <<G4endl;
G4cout <<"Impact parameter = " <<r/fermi <<" fm" <<G4endl;
G4cout <<"# Abraded nucleons = " <<Dabr <<G4endl;
}
//
//
// The number of abraded nucleons must be no greater than the number of
// nucleons in either the projectile or the target. If AP - Dabr < 2 or
// AT - Dabr < 2 then either we have only a nucleon left behind in the
// projectile/target or we've tried to abrade too many nucleons - and Dabr
// should be limited.
//
if (AP - (G4double) Dabr < 2.0) Dabr = (G4int) AP;
if (AT - (G4double) Dabr < 2.0) Dabr = (G4int) AT;
//
//
// Determine the abraded secondary nucleons from the projectile. *fragmentP
// is a pointer to the prefragment from the projectile and nSecP is the number
// of nucleons in theParticleChange which have been abraded. The total energy
// from these is determined.
//
G4ThreeVector boost = pP.findBoostToCM();
G4Fragment *fragmentP = GetAbradedNucleons (Dabr, AP, ZP, rP);
G4int nSecP = theParticleChange.GetNumberOfSecondaries();
G4int i = 0;
for (i=0; i<nSecP; i++)
{
TotalEPost += theParticleChange.GetSecondary(i)->
GetParticle()->GetTotalEnergy();
}
//
//
// Determine the number of spectators in the interaction region for the
// projectile.
//
G4int DspcP = (G4int) (AP*F) - Dabr;
if (DspcP <= 0) DspcP = 0;
else if (DspcP > AP-Dabr) DspcP = ((G4int) AP) - Dabr;
//
//
// Determine excitation energy associated with excess surface area of the
// projectile (EsP) and the excitation due to scattering of nucleons which are
// retained within the projectile (ExP). Add the total energy from the excited
// nucleus to the total energy of the secondaries.
//
G4bool excitationAbsorbedByProjectile = false;
if (fragmentP != NULL)
{
G4double EsP = theAbrasionGeometry->GetExcitationEnergyOfProjectile();
G4double ExP = 0.0;
if (Dabr < AT)
excitationAbsorbedByProjectile = G4UniformRand() < 0.5;
if (excitationAbsorbedByProjectile)
ExP = GetNucleonInducedExcitation(rP, rT, r);
G4double xP = EsP + ExP;
if (xP > B*(AP-Dabr)) xP = B*(AP-Dabr);
G4LorentzVector lorentzVector = fragmentP->GetMomentum();
lorentzVector.setE(lorentzVector.e()+xP);
fragmentP->SetMomentum(lorentzVector);
TotalEPost += lorentzVector.e();
}
G4double EMassP = TotalEPost;
//
//
// Determine the abraded secondary nucleons from the target. Note that it's
// assumed that the same number of nucleons are abraded from the target as for
// the projectile, and obviously no boost is applied to the products. *fragmentT
// is a pointer to the prefragment from the target and nSec is the total number
// of nucleons in theParticleChange which have been abraded. The total energy
// from these is determined.
//
G4Fragment *fragmentT = GetAbradedNucleons (Dabr, AT, ZT, rT);
G4int nSec = theParticleChange.GetNumberOfSecondaries();
for (i=nSecP; i<nSec; i++)
{
TotalEPost += theParticleChange.GetSecondary(i)->
GetParticle()->GetTotalEnergy();
}
//
//
// Determine the number of spectators in the interaction region for the
// target.
//
G4int DspcT = (G4int) (AT*F) - Dabr;
if (DspcT <= 0) DspcT = 0;
else if (DspcT > AP-Dabr) DspcT = ((G4int) AT) - Dabr;
//
//
// Determine excitation energy associated with excess surface area of the
// target (EsT) and the excitation due to scattering of nucleons which are
// retained within the target (ExT). Add the total energy from the excited
// nucleus to the total energy of the secondaries.
//
if (fragmentT != NULL)
{
G4double EsT = theAbrasionGeometry->GetExcitationEnergyOfTarget();
G4double ExT = 0.0;
if (!excitationAbsorbedByProjectile)
ExT = GetNucleonInducedExcitation(rT, rP, r);
G4double xT = EsT + ExT;
if (xT > B*(AT-Dabr)) xT = B*(AT-Dabr);
G4LorentzVector lorentzVector = fragmentT->GetMomentum();
lorentzVector.setE(lorentzVector.e()+xT);
fragmentT->SetMomentum(lorentzVector);
TotalEPost += lorentzVector.e();
}
//
//
// Now determine the difference between the pre and post interaction
// energy - this will be used to determine the Lorentz boost if conservation
// of energy is to be imposed/attempted.
//
G4double deltaE = TotalEPre - TotalEPost;
if (deltaE > 0.0 && conserveEnergy)
{
G4double beta = std::sqrt(1.0 - EMassP*EMassP/std::pow(deltaE+EMassP,2.0));
boost = boost / boost.mag() * beta;
}
//
//
// Now boost the secondaries from the projectile.
//
G4ThreeVector pBalance = pP.vect();
for (i=0; i<nSecP; i++)
{
G4DynamicParticle *dynamicP = theParticleChange.GetSecondary(i)->
GetParticle();
G4LorentzVector lorentzVector = dynamicP->Get4Momentum();
lorentzVector.boost(-boost);
dynamicP->Set4Momentum(lorentzVector);
pBalance -= lorentzVector.vect();
}
//
//
// Set the boost for the projectile prefragment. This is now based on the
// conservation of momentum. However, if the user selected momentum of the
// prefragment is not to be conserved this simply boosted to the velocity of the
// original projectile times the ratio of the unexcited to the excited mass
// of the prefragment (the excitation increases the effective mass of the
// prefragment, and therefore modifying the boost is an attempt to prevent
// the momentum of the prefragment being excessive).
//
if (fragmentP != NULL)
{
G4LorentzVector lorentzVector = fragmentP->GetMomentum();
G4double m = lorentzVector.m();
if (conserveMomentum)
fragmentP->SetMomentum
(G4LorentzVector(pBalance,std::sqrt(pBalance.mag2()+m*m+1.0*eV*eV)));
else
{
G4double mg = fragmentP->GetGroundStateMass();
fragmentP->SetMomentum(lorentzVector.boost(-boost * mg/m));
}
}
//
//
// Output information to user if verbose information requested.
//
if (verboseLevel >= 2)
{
G4cout <<G4endl;
G4cout <<"-----------------------------------" <<G4endl;
G4cout <<"Secondary nucleons from projectile:" <<G4endl;
G4cout <<"-----------------------------------" <<G4endl;
G4cout.precision(7);
for (i=0; i<nSecP; i++)
{
G4cout <<"Particle # " <<i <<G4endl;
theParticleChange.GetSecondary(i)->GetParticle()->DumpInfo();
G4DynamicParticle *dyn = theParticleChange.GetSecondary(i)->GetParticle();
G4cout <<"New nucleon (P) " <<dyn->GetDefinition()->GetParticleName()
<<" : " <<dyn->Get4Momentum()
<<G4endl;
}
G4cout <<"---------------------------" <<G4endl;
G4cout <<"The projectile prefragment:" <<G4endl;
G4cout <<"---------------------------" <<G4endl;
if (fragmentP != NULL)
G4cout <<*fragmentP <<G4endl;
else
G4cout <<"(No residual prefragment)" <<G4endl;
G4cout <<G4endl;
G4cout <<"-------------------------------" <<G4endl;
G4cout <<"Secondary nucleons from target:" <<G4endl;
G4cout <<"-------------------------------" <<G4endl;
G4cout.precision(7);
for (i=nSecP; i<nSec; i++)
{
G4cout <<"Particle # " <<i <<G4endl;
theParticleChange.GetSecondary(i)->GetParticle()->DumpInfo();
G4DynamicParticle *dyn = theParticleChange.GetSecondary(i)->GetParticle();
G4cout <<"New nucleon (T) " <<dyn->GetDefinition()->GetParticleName()
<<" : " <<dyn->Get4Momentum()
<<G4endl;
}
G4cout <<"-----------------------" <<G4endl;
G4cout <<"The target prefragment:" <<G4endl;
G4cout <<"-----------------------" <<G4endl;
if (fragmentT != NULL)
G4cout <<*fragmentT <<G4endl;
else
G4cout <<"(No residual prefragment)" <<G4endl;
}
//
//
// Now we can decay the nuclear fragments if present. The secondaries are
// collected and boosted as well. This is performed first for the projectile...
//
if (fragmentP !=NULL)
{
G4ReactionProductVector *products = NULL;
if (fragmentP->GetZ() != fragmentP->GetA())
products = theExcitationHandler->BreakItUp(*fragmentP);
else
products = theExcitationHandlerx->BreakItUp(*fragmentP);
delete fragmentP;
fragmentP = NULL;
G4ReactionProductVector::iterator iter;
for (iter = products->begin(); iter != products->end(); ++iter)
{
G4DynamicParticle *secondary =
new G4DynamicParticle((*iter)->GetDefinition(),
(*iter)->GetTotalEnergy(), (*iter)->GetMomentum());
theParticleChange.AddSecondary (secondary); // Added MHM 20050118
G4String particleName = (*iter)->GetDefinition()->GetParticleName();
delete (*iter); // get rid of leftover particle def! // Added MHM 20050118
if (verboseLevel >= 2 && particleName.find("[",0) < particleName.size())
{
G4cout <<"------------------------" <<G4endl;
G4cout <<"The projectile fragment:" <<G4endl;
G4cout <<"------------------------" <<G4endl;
G4cout <<" fragmentP = " <<particleName
<<" Energy = " <<secondary->GetKineticEnergy()
<<G4endl;
}
}
delete products; // Added MHM 20050118
}
//
//
// Now decay the target nucleus - no boost is applied since in this
// approximation it is assumed that there is negligible momentum transfer from
// the projectile.
//
if (fragmentT != NULL)
{
G4ReactionProductVector *products = NULL;
if (fragmentT->GetZ() != fragmentT->GetA())
products = theExcitationHandler->BreakItUp(*fragmentT);
else
products = theExcitationHandlerx->BreakItUp(*fragmentT);
delete fragmentT;
fragmentT = NULL;
G4ReactionProductVector::iterator iter;
for (iter = products->begin(); iter != products->end(); ++iter)
{
G4DynamicParticle *secondary =
new G4DynamicParticle((*iter)->GetDefinition(),
(*iter)->GetTotalEnergy(), (*iter)->GetMomentum());
theParticleChange.AddSecondary (secondary);
G4String particleName = (*iter)->GetDefinition()->GetParticleName();
delete (*iter); // get rid of leftover particle def! // Added MHM 20050118
if (verboseLevel >= 2 && particleName.find("[",0) < particleName.size())
{
G4cout <<"--------------------" <<G4endl;
G4cout <<"The target fragment:" <<G4endl;
G4cout <<"--------------------" <<G4endl;
G4cout <<" fragmentT = " <<particleName
<<" Energy = " <<secondary->GetKineticEnergy()
<<G4endl;
}
}
delete products; // Added MHM 20050118
}
if (verboseLevel >= 2)
G4cout <<"########################################"
<<"########################################"
<<G4endl;
delete theAbrasionGeometry;
return &theParticleChange;
}
////////////////////////////////////////////////////////////////////////////////
//
G4Fragment *G4WilsonAbrasionModel::GetAbradedNucleons (G4int Dabr, G4double A,
G4double Z, G4double r)
{
//
//
// Initialise variables. tau is the Fermi radius of the nucleus. The variables
// p..., C... and g(amma) are used to help sample the secondary nucleon
// spectrum.
//
G4double pK = hbarc * std::pow(9.0 * pi / 4.0 * A, third) / (1.29 * r);
if (A <= 24.0) pK *= -0.229*std::pow(A,third) + 1.62;
G4double pKsq = pK * pK;
G4double p1sq = 2.0/5.0 * pKsq;
G4double p2sq = 6.0/5.0 * pKsq;
G4double p3sq = 500.0 * 500.0;
G4double C1 = 1.0;
G4double C2 = 0.03;
G4double C3 = 0.0002;
G4double g = 90.0 * MeV;
G4double maxn = C1 + C2 + C3;
//
//
// initialise the number of secondary nucleons abraded to zero, and initially set
// the type of nucleon abraded to proton ... just for now.
//
G4double Aabr = 0.0;
G4double Zabr = 0.0;
G4ParticleDefinition *typeNucleon = G4Proton::ProtonDefinition();
G4DynamicParticle *dynamicNucleon = NULL;
G4ParticleMomentum pabr(0.0, 0.0, 0.0);
//
//
// Now go through each abraded nucleon and sample type, spectrum and angle.
//
for (G4int i=0; i<Dabr; i++)
{
//
//
// Sample the nucleon momentum distribution by simple rejection techniques. We
// reject values of p == 0.0 since this causes bad behaviour in the sinh term.
//
G4double p = 0.0;
G4bool found = false;
while (!found)
{
while (p <= 0.0) p = npK * pK * G4UniformRand();
G4double psq = p * p;
found = maxn * G4UniformRand() < C1*std::exp(-psq/p1sq/2.0) +
C2*std::exp(-psq/p2sq/2.0) + C3*std::exp(-psq/p3sq/2.0) + p/g/std::sinh(p/g);
}
//
//
// Determine the type of particle abraded. Can only be proton or neutron,
// and the probability is determine to be proportional to the ratio as found
// in the nucleus at each stage.
//
G4double prob = (Z-Zabr)/(A-Aabr);
if (G4UniformRand()<prob)
{
Zabr++;
typeNucleon = G4Proton::ProtonDefinition();
}
else
typeNucleon = G4Neutron::NeutronDefinition();
Aabr++;
//
//
// The angular distribution of the secondary nucleons is approximated to an
// isotropic distribution in the rest frame of the nucleus (this will be Lorentz
// boosted later.
//
G4double costheta = 2.*G4UniformRand()-1.0;
G4double sintheta = std::sqrt((1.0 - costheta)*(1.0 + costheta));
G4double phi = 2.0*pi*G4UniformRand()*rad;
G4ThreeVector direction(sintheta*std::cos(phi),sintheta*std::sin(phi),costheta);
G4double nucleonMass = typeNucleon->GetPDGMass();
G4double E = std::sqrt(p*p + nucleonMass*nucleonMass)-nucleonMass;
dynamicNucleon = new G4DynamicParticle(typeNucleon,direction,E);
theParticleChange.AddSecondary (dynamicNucleon);
pabr += p*direction;
}
//
//
// Next determine the details of the nuclear prefragment .. that is if there
// is one or more protons in the residue. (Note that the 1 eV in the total
// energy is a safety factor to avoid any possibility of negative rest mass
// energy.)
//
G4Fragment *fragment = NULL;
if (Z-Zabr>=1.0)
{
G4double ionMass = G4ParticleTable::GetParticleTable()->GetIonTable()->
GetIonMass(G4lrint(Z-Zabr),G4lrint(A-Aabr));
G4double E = std::sqrt(pabr.mag2() + ionMass*ionMass);
G4LorentzVector lorentzVector = G4LorentzVector(-pabr, E + 1.0*eV);
fragment =
new G4Fragment((G4int) (A-Aabr), (G4int) (Z-Zabr), lorentzVector);
}
return fragment;
}
////////////////////////////////////////////////////////////////////////////////
//
G4double G4WilsonAbrasionModel::GetNucleonInducedExcitation
(G4double rP, G4double rT, G4double r)
{
//
//
// Initialise variables.
//
G4double Cl = 0.0;
G4double rPsq = rP * rP;
G4double rTsq = rT * rT;
G4double rsq = r * r;
//
//
// Depending upon the impact parameter, a different form of the chord length is
// is used.
//
if (r > rT) Cl = 2.0*std::sqrt(rPsq + 2.0*r*rT - rsq - rTsq);
else Cl = 2.0*rP;
G4double bP = (rPsq+rsq-rTsq)/2.0/r;
G4double Ct = 2.0*std::sqrt(rPsq - bP*bP);
G4double Ex = 13.0 * Cl / fermi;
if (Ct > 1.5*fermi)
Ex += 13.0 * Cl / fermi /3.0 * (Ct/fermi - 1.5);
return Ex;
}
////////////////////////////////////////////////////////////////////////////////
//
void G4WilsonAbrasionModel::SetUseAblation (G4bool useAblation1)
{
if (useAblation != useAblation1)
{
useAblation = useAblation1;
delete theExcitationHandler;
delete theExcitationHandlerx;
theExcitationHandler = new G4ExcitationHandler;
theExcitationHandlerx = new G4ExcitationHandler;
if (useAblation)
{
theAblation = new G4WilsonAblationModel;
theAblation->SetVerboseLevel(verboseLevel);
theExcitationHandler->SetEvaporation(theAblation);
theExcitationHandlerx->SetEvaporation(theAblation);
}
else
{
theAblation = NULL;
G4Evaporation * theEvaporation = new G4Evaporation;
G4FermiBreakUp * theFermiBreakUp = new G4FermiBreakUp;
G4StatMF * theMF = new G4StatMF;
theExcitationHandler->SetEvaporation(theEvaporation);
theExcitationHandler->SetFermiModel(theFermiBreakUp);
theExcitationHandler->SetMultiFragmentation(theMF);
theExcitationHandler->SetMaxAandZForFermiBreakUp(12, 6);
theExcitationHandler->SetMinEForMultiFrag(5.0*MeV);
theEvaporation = new G4Evaporation;
theFermiBreakUp = new G4FermiBreakUp;
theExcitationHandlerx->SetEvaporation(theEvaporation);
theExcitationHandlerx->SetFermiModel(theFermiBreakUp);
theExcitationHandlerx->SetMaxAandZForFermiBreakUp(12, 6);
}
}
return;
}
////////////////////////////////////////////////////////////////////////////////
//
void G4WilsonAbrasionModel::PrintWelcomeMessage ()
{
G4cout <<G4endl;
G4cout <<" *****************************************************************"
<<G4endl;
G4cout <<" Nuclear abrasion model for nuclear-nuclear interactions activated"
<<G4endl;
G4cout <<" (Written by QinetiQ Ltd for the European Space Agency)"
<<G4endl;
G4cout <<" *****************************************************************"
<<G4endl;
G4cout << G4endl;
return;
}
////////////////////////////////////////////////////////////////////////////////
//
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