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6399a014b611a4aa09ecba225418222dac261ca1
geant4/source/processes/electromagnetic/lowenergy/src/G4LivermoreGammaConversionModelRC.cc
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Gabriele Cosmo 6399a014b6 Import Geant4 11.0.0.beta source tree
2021-06-25 16:12:29 +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. *
// * 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. *
// ********************************************************************
//
// Author: Sebastien Incerti
// 22 January 2012
// on base of G4LivermoreGammaConversionModelRC (original version)
// and G4LivermoreRayleighModel (MT version)
#include "G4LivermoreGammaConversionModelRC.hh"
#include "G4PhysicalConstants.hh"
#include "G4SystemOfUnits.hh"
#include "G4Log.hh"
#include "G4Electron.hh"
#include "G4Positron.hh"
#include "G4Gamma.hh"
#include "G4ParticleChangeForGamma.hh"
#include "G4Exp.hh"
#include "G4AutoLock.hh"
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
using namespace std;
namespace { G4Mutex LivermoreGammaConversionModelRCMutex = G4MUTEX_INITIALIZER; }
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
G4PhysicsFreeVector* G4LivermoreGammaConversionModelRC::data[] = {nullptr};
G4LivermoreGammaConversionModelRC::G4LivermoreGammaConversionModelRC
(const G4ParticleDefinition*, const G4String& nam)
:G4VEmModel(nam),smallEnergy(2.*MeV),isInitialised(false)
{
fParticleChange = nullptr;
lowEnergyLimit = 2.0*electron_mass_c2;
verboseLevel= 0;
// Verbosity scale for debugging purposes:
// 0 = nothing
// 1 = calculation of cross sections, file openings...
// 2 = entering in methods
if(verboseLevel > 0)
{
G4cout << "G4LivermoreGammaConversionModelRC is constructed " << G4endl;
}
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
G4LivermoreGammaConversionModelRC::~G4LivermoreGammaConversionModelRC()
{
if(IsMaster()) {
for(G4int i=0; i<maxZ; ++i) {
if(data[i]) {
delete data[i];
data[i] = nullptr;
}
}
}
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
void G4LivermoreGammaConversionModelRC::Initialise(
const G4ParticleDefinition* particle,
const G4DataVector& cuts)
{
if (verboseLevel > 1)
{
G4cout << "Calling Initialise() of G4LivermoreGammaConversionModelRC."
<< G4endl
<< "Energy range: "
<< LowEnergyLimit() / MeV << " MeV - "
<< HighEnergyLimit() / GeV << " GeV"
<< G4endl;
}
if(IsMaster())
{
// Initialise element selector
InitialiseElementSelectors(particle, cuts);
// Access to elements
char* path = std::getenv("G4LEDATA");
G4ProductionCutsTable* theCoupleTable =
G4ProductionCutsTable::GetProductionCutsTable();
G4int numOfCouples = theCoupleTable->GetTableSize();
for(G4int i=0; i<numOfCouples; ++i)
{
const G4Material* material =
theCoupleTable->GetMaterialCutsCouple(i)->GetMaterial();
const G4ElementVector* theElementVector = material->GetElementVector();
G4int nelm = material->GetNumberOfElements();
for (G4int j=0; j<nelm; ++j)
{
G4int Z = (G4int)(*theElementVector)[j]->GetZ();
if(Z < 1) { Z = 1; }
else if(Z > maxZ) { Z = maxZ; }
if(!data[Z]) { ReadData(Z, path); }
}
}
}
if(isInitialised) { return; }
fParticleChange = GetParticleChangeForGamma();
isInitialised = true;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
void G4LivermoreGammaConversionModelRC::InitialiseLocal(
const G4ParticleDefinition*, G4VEmModel* masterModel)
{
SetElementSelectors(masterModel->GetElementSelectors());
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
G4double
G4LivermoreGammaConversionModelRC::MinPrimaryEnergy(const G4Material*,
const G4ParticleDefinition*,
G4double)
{
return lowEnergyLimit;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
void G4LivermoreGammaConversionModelRC::ReadData(size_t Z, const char* path)
{
if (verboseLevel > 1)
{
G4cout << "Calling ReadData() of G4LivermoreGammaConversionModelRC"
<< G4endl;
}
if(data[Z]) { return; }
const char* datadir = path;
if(!datadir)
{
datadir = std::getenv("G4LEDATA");
if(!datadir)
{
G4Exception("G4LivermoreGammaConversionModelRC::ReadData()",
"em0006",FatalException,
"Environment variable G4LEDATA not defined");
return;
}
}
//
data[Z] = new G4PhysicsFreeVector(0,/*spline=*/true);
//
std::ostringstream ost;
ost << datadir << "/livermore/pair/pp-cs-" << Z <<".dat";
std::ifstream fin(ost.str().c_str());
if( !fin.is_open())
{
G4ExceptionDescription ed;
ed << "G4LivermoreGammaConversionModelRC data file <" << ost.str().c_str()
<< "> is not opened!" << G4endl;
G4Exception("G4LivermoreGammaConversionModelRC::ReadData()",
"em0003",FatalException,
ed,"G4LEDATA version should be G4EMLOW6.27 or later.");
return;
}
else
{
if(verboseLevel > 3) { G4cout << "File " << ost.str()
<< " is opened by G4LivermoreGammaConversionModelRC" << G4endl;}
data[Z]->Retrieve(fin, true);
}
// Activation of spline interpolation
data[Z] ->FillSecondDerivatives();
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
G4double
G4LivermoreGammaConversionModelRC::ComputeCrossSectionPerAtom(const G4ParticleDefinition*,
G4double GammaEnergy,
G4double Z, G4double,
G4double, G4double)
{
if (verboseLevel > 1)
{
G4cout << "Calling ComputeCrossSectionPerAtom() of G4LivermoreGammaConversionModelRC"
<< G4endl;
}
if (GammaEnergy < lowEnergyLimit) { return 0.0; }
G4double xs = 0.0;
G4int intZ=G4int(Z);
if(intZ < 1 || intZ > maxZ) { return xs; }
G4PhysicsFreeVector* pv = data[intZ];
// if element was not initialised
// do initialisation safely for MT mode
if(!pv)
{
InitialiseForElement(0, intZ);
pv = data[intZ];
if(!pv) { return xs; }
}
// x-section is taken from the table
xs = pv->Value(GammaEnergy);
if(verboseLevel > 0)
{
G4int n = pv->GetVectorLength() - 1;
G4cout << "****** DEBUG: tcs value for Z=" << Z << " at energy (MeV)="
<< GammaEnergy/MeV << G4endl;
G4cout << " cs (Geant4 internal unit)=" << xs << G4endl;
G4cout << " -> first cs value in EADL data file (iu) =" << (*pv)[0] << G4endl;
G4cout << " -> last cs value in EADL data file (iu) =" << (*pv)[n] << G4endl;
G4cout << "*********************************************************" << G4endl;
}
return xs;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
void G4LivermoreGammaConversionModelRC::SampleSecondaries(
std::vector<G4DynamicParticle*>* fvect,
const G4MaterialCutsCouple* couple,
const G4DynamicParticle* aDynamicGamma,
G4double, G4double)
{
// The energies of the e+ e- secondaries are sampled using the Bethe - Heitler
// cross sections with Coulomb correction. A modified version of the random
// number techniques of Butcher & Messel is used (Nuc Phys 20(1960),15).
// Note 1 : Effects due to the breakdown of the Born approximation at low
// energy are ignored.
// Note 2 : The differential cross section implicitly takes account of
// pair creation in both nuclear and atomic electron fields. However triplet
// prodution is not generated.
if (verboseLevel > 1) {
G4cout << "Calling SampleSecondaries() of G4LivermoreGammaConversionModelRC"
<< G4endl;
}
G4double photonEnergy = aDynamicGamma->GetKineticEnergy();
G4ParticleMomentum photonDirection = aDynamicGamma->GetMomentumDirection();
G4double epsilon ;
G4double epsilon0Local = electron_mass_c2 / photonEnergy ;
G4double electronTotEnergy = 0.0;
G4double positronTotEnergy = 0.0;
G4double HardPhotonEnergy = 0.0;
// Do it fast if photon energy < 2. MeV
if (photonEnergy < smallEnergy )
{
epsilon = epsilon0Local + (0.5 - epsilon0Local) * G4UniformRand();
if (G4UniformRand() > 0.5)
{
electronTotEnergy = (1. - epsilon) * photonEnergy;
positronTotEnergy = epsilon * photonEnergy;
}
else
{
positronTotEnergy = (1. - epsilon) * photonEnergy;
electronTotEnergy = epsilon * photonEnergy;
}
}
else
{
// Select randomly one element in the current material
const G4ParticleDefinition* particle = aDynamicGamma->GetDefinition();
const G4Element* element = SelectRandomAtom(couple,particle,photonEnergy);
if (element == 0)
{
G4cout << "G4LivermoreGammaConversionModelRC::SampleSecondaries - element = 0"
<< G4endl;
return;
}
G4IonisParamElm* ionisation = element->GetIonisation();
if (ionisation == 0)
{
G4cout << "G4LivermoreGammaConversionModelRC::SampleSecondaries - ionisation = 0"
<< G4endl;
return;
}
// Extract Coulomb factor for this Element
G4double fZ = 8. * (ionisation->GetlogZ3());
if (photonEnergy > 50. * MeV) fZ += 8. * (element->GetfCoulomb());
// Limits of the screening variable
G4double screenFactor = 136. * epsilon0Local / (element->GetIonisation()->GetZ3()) ;
G4double screenMax = G4Exp ((42.24 - fZ)/8.368) - 0.952 ;
G4double screenMin = std::min(4.*screenFactor,screenMax) ;
// Limits of the energy sampling
G4double epsilon1 = 0.5 - 0.5 * std::sqrt(1. - screenMin / screenMax) ;
G4double epsilonMin = std::max(epsilon0Local,epsilon1);
G4double epsilonRange = 0.5 - epsilonMin ;
// Sample the energy rate of the created electron (or positron)
G4double screen;
G4double gReject ;
G4double f10 = ScreenFunction1(screenMin) - fZ;
G4double f20 = ScreenFunction2(screenMin) - fZ;
G4double normF1 = std::max(f10 * epsilonRange * epsilonRange,0.);
G4double normF2 = std::max(1.5 * f20,0.);
// Method for Radiative corrections
G4double a=393.3750918, b=115.3070201, c=810.6428451, d=19.96497475, e=1016.874592, f=1.936685510,
gLocal=751.2140962, h=0.099751048, i=299.9466339, j=0.002057250, k=49.81034926;
G4double aa=-18.6371131, bb=-1729.95248, cc=9450.971186, dd=106336.0145, ee=55143.09287, ff=-117602.840,
gg=-721455.467, hh=693957.8635, ii=156266.1085, jj=533209.9347;
G4double Rechazo = 0.;
G4double logepsMin = log(epsilonMin);
G4double NormaRC = a + b*logepsMin + c/logepsMin + d*pow(logepsMin,2.) + e/pow(logepsMin,2.) + f*pow(logepsMin,3.) +
gLocal/pow(logepsMin,3.) + h*pow(logepsMin,4.) + i/pow(logepsMin,4.) + j*pow(logepsMin,5.) +
k/pow(logepsMin,5.);
G4double HardPhotonThreshold = 0.08;
G4double r1, r2, r3, beta=0, gbeta, sigt = 582.068, sigh, rejet;
G4double cg = (11./2.)/(G4Exp(-11.*HardPhotonThreshold/2.)-G4Exp(-11./2.));
r1 = G4UniformRand();
sigh = 1028.58*G4Exp(-HardPhotonThreshold/0.09033) + 136.63; // sigma hard
if (r1 > 1.- sigh/sigt) {
r2 = G4UniformRand();
rejet = 0.;
while (r2 > rejet) {
r3 = G4UniformRand();
beta = (-2./11.)*log(G4Exp(-0.08*11./2.)-r3*11./(2.*cg));
gbeta = G4Exp(-11.*beta/2.);
rejet = fbeta(beta)/(8000.*gbeta);
}
HardPhotonEnergy = beta * photonEnergy;
}
else{
HardPhotonEnergy = 0.;
}
photonEnergy -= HardPhotonEnergy;
do
{
do
{
if (normF1 / (normF1 + normF2) > G4UniformRand() )
{
epsilon = 0.5 - epsilonRange * std::pow(G4UniformRand(), 0.333333) ;
screen = screenFactor / (epsilon * (1. - epsilon));
gReject = (ScreenFunction1(screen) - fZ) / f10 ;
}
else
{
epsilon = epsilonMin + epsilonRange * G4UniformRand();
screen = screenFactor / (epsilon * (1 - epsilon));
gReject = (ScreenFunction2(screen) - fZ) / f20 ;
}
} while ( gReject < G4UniformRand() );
if (G4UniformRand()>0.5) epsilon = (1. - epsilon); // Extención de Epsilon hasta 1.
G4double logepsilon = log(epsilon);
G4double deltaP_R1 = 1. + (a + b*logepsilon + c/logepsilon + d*pow(logepsilon,2.) + e/pow(logepsilon,2.) +
f*pow(logepsilon,3.) + gLocal/pow(logepsilon,3.) + h*pow(logepsilon,4.) + i/pow(logepsilon,4.) +
j*pow(logepsilon,5.) + k/pow(logepsilon,5.))/100.;
G4double deltaP_R2 = 1.+((aa + cc*logepsilon + ee*pow(logepsilon,2.) + gg*pow(logepsilon,3.) + ii*pow(logepsilon,4.))
/ (1. + bb*logepsilon + dd*pow(logepsilon,2.) + ff*pow(logepsilon,3.) + hh*pow(logepsilon,4.)
+ jj*pow(logepsilon,5.) ))/100.;
if (epsilon <= 0.5)
{
Rechazo = deltaP_R1/NormaRC;
}
else
{
Rechazo = deltaP_R2/NormaRC;
}
} while (Rechazo < G4UniformRand() );
electronTotEnergy = (1. - epsilon) * photonEnergy;
positronTotEnergy = epsilon * photonEnergy;
} // End of epsilon sampling
// Fix charges randomly
// Scattered electron (positron) angles. ( Z - axis along the parent photon)
// Universal distribution suggested by L. Urban (Geant3 manual (1993) Phys211),
// derived from Tsai distribution (Rev. Mod. Phys. 49, 421 (1977)
G4double u;
const G4double a1 = 0.625;
G4double a2 = 3. * a1;
if (0.25 > G4UniformRand())
{
u = - G4Log(G4UniformRand() * G4UniformRand()) / a1 ;
}
else
{
u = - G4Log(G4UniformRand() * G4UniformRand()) / a2 ;
}
G4double thetaEle = u*electron_mass_c2/electronTotEnergy;
G4double thetaPos = u*electron_mass_c2/positronTotEnergy;
G4double phi = twopi * G4UniformRand();
G4double dxEle= std::sin(thetaEle)*std::cos(phi),dyEle= std::sin(thetaEle)*std::sin(phi),dzEle=std::cos(thetaEle);
G4double dxPos=-std::sin(thetaPos)*std::cos(phi),dyPos=-std::sin(thetaPos)*std::sin(phi),dzPos=std::cos(thetaPos);
// Kinematics of the created pair:
// the electron and positron are assumed to have a symetric angular
// distribution with respect to the Z axis along the parent photon
G4double electronKineEnergy = std::max(0.,electronTotEnergy - electron_mass_c2) ;
G4ThreeVector electronDirection (dxEle, dyEle, dzEle);
electronDirection.rotateUz(photonDirection);
G4DynamicParticle* particle1 = new G4DynamicParticle (G4Electron::Electron(),
electronDirection,
electronKineEnergy);
// The e+ is always created
G4double positronKineEnergy = std::max(0.,positronTotEnergy - electron_mass_c2) ;
G4ThreeVector positronDirection (dxPos, dyPos, dzPos);
positronDirection.rotateUz(photonDirection);
// Create G4DynamicParticle object for the particle2
G4DynamicParticle* particle2 = new G4DynamicParticle(G4Positron::Positron(),
positronDirection,
positronKineEnergy);
// Fill output vector
fvect->push_back(particle1);
fvect->push_back(particle2);
if (HardPhotonEnergy > 0.)
{
G4double thetaHardPhoton = u*electron_mass_c2/HardPhotonEnergy;
phi = twopi * G4UniformRand();
G4double dxHardP= std::sin(thetaHardPhoton)*std::cos(phi);
G4double dyHardP= std::sin(thetaHardPhoton)*std::sin(phi);
G4double dzHardP =std::cos(thetaHardPhoton);
G4ThreeVector hardPhotonDirection (dxHardP, dyHardP, dzHardP);
hardPhotonDirection.rotateUz(photonDirection);
G4DynamicParticle* particle3 = new G4DynamicParticle (G4Gamma::Gamma(),
hardPhotonDirection,
HardPhotonEnergy);
fvect->push_back(particle3);
}
// kill incident photon
fParticleChange->SetProposedKineticEnergy(0.);
fParticleChange->ProposeTrackStatus(fStopAndKill);
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
G4double G4LivermoreGammaConversionModelRC::ScreenFunction1(G4double screenVariable)
{
// Compute the value of the screening function 3*phi1 - phi2
G4double value;
if (screenVariable > 1.)
value = 42.24 - 8.368 * G4Log(screenVariable + 0.952);
else
value = 42.392 - screenVariable * (7.796 - 1.961 * screenVariable);
return value;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
G4double G4LivermoreGammaConversionModelRC::ScreenFunction2(G4double screenVariable)
{
// Compute the value of the screening function 1.5*phi1 - 0.5*phi2
G4double value;
if (screenVariable > 1.)
value = 42.24 - 8.368 * G4Log(screenVariable + 0.952);
else
value = 41.405 - screenVariable * (5.828 - 0.8945 * screenVariable);
return value;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
G4double G4LivermoreGammaConversionModelRC::fbeta(G4double x)
{
// compute the probabililty distribution for hard photon
G4double gamma, eta, d, p1, p2, p3, p4, p5, p6, p7, ffbeta;
gamma = (1.-x)*(1.-x)/x;
eta = (1.-x)/(1.+x);
d = Dilog(1./x)-Dilog(x);
p1 = -1.*(25528.*pow(gamma,2) + 116044.* gamma +151556.)/105.;
p2 = 256.* pow(gamma,3) + 1092.* pow(gamma,2) +1260.*gamma + 420.;
p3 = (676.*pow(gamma,3) + 9877.*pow(gamma,2) + 58415.*gamma + 62160.)/105.;
p4 = 64.*pow(gamma,3) + 305.*pow(gamma,2) + 475.*gamma + 269. - 276./gamma;
p5 = (676.*pow(gamma,3) + 38109.*pow(gamma,2) + 211637.*gamma + 266660. - 53632./gamma)/105.;
p6 = 32.*pow(gamma,2) + 416.*gamma + 1310. +1184./gamma;
p7 = 128.*pow(gamma,3) + 802.*pow(gamma,2) + 1028.*gamma - 470. - 1184./gamma;
ffbeta = (1.-x) * (p1 + p2*pi*pi/6. + p3*log(gamma) +
p4*pow(log(x),2) + (p5 + p6*log(gamma))*eta*log(x) + p7*d*eta);
return ffbeta;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
G4double G4LivermoreGammaConversionModelRC::Dilog(G4double y)
{
G4double fdilog = 0.0;
if (y <= 0.5) {
fdilog = pow(pi,2)/6. + (1.-y)*(log(1-y)-1.)+pow((1.-y),2)*((1./2.)*log(1.-y)-1./4.)
+pow((1.-y),3)*((1./3.)*log(1.-y)-1./9.)+pow((1.-y),4)*((1./4.)*log(1.-y)-1./16.);
}
if (0.5 < y && y < 2.) {
fdilog = 1.-y+pow((1.-y),2)/4.+pow((1.-y),3)/9.+pow((1.-y),4)/16.+
pow((1.-y),5)/25.+pow((1.-y),6)/36.+pow((1.-y),7)/49.;
}
if (y >= 2.) {
fdilog = -pow(log(y),2)/2. - pow(pi,2)/6. + (log(y)+1.)/y +
(log(y)/2.+1./4.)/pow(y,2) + (log(y)/3.+1./9.)/pow(y,3);
}
return fdilog;
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
void G4LivermoreGammaConversionModelRC::InitialiseForElement(
const G4ParticleDefinition*,
G4int Z)
{
G4AutoLock l(&LivermoreGammaConversionModelRCMutex);
if(!data[Z]) { ReadData(Z); }
l.unlock();
}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
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