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geant4/source/processes/hadronic/models/coherent_elastic/include/G4DiffuseElastic.hh
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Gabriele Cosmo 96c8bcd0af Import Geant4 9.1.0 source tree
2016-06-09 15:37:50 +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. *
// ********************************************************************
//
//
// $Id: G4DiffuseElastic.hh,v 1.13 2007/11/06 17:01:20 grichine Exp $
// GEANT4 tag $Name: geant4-09-01 $
//
//
// G4 Model: optical elastic scattering with 4-momentum balance
//
// Class Description
// Final state production model for hadron nuclear elastic scattering;
// Class Description - End
//
//
// 24.05.07 V. Grichine first implementation for hadron (no Coulomb) elastic scattering
// 04.09.07 V. Grichine implementation for Coulomb elastic scattering
#ifndef G4DiffuseElastic_h
#define G4DiffuseElastic_h 1
#include "globals.hh"
#include "G4HadronicInteraction.hh"
#include "G4HadProjectile.hh"
#include "G4Nucleus.hh"
using namespace std;
class G4ParticleDefinition;
class G4PhysicsTable;
class G4PhysicsLogVector;
class G4DiffuseElastic : public G4HadronicInteraction
{
public:
G4DiffuseElastic();
G4DiffuseElastic(const G4ParticleDefinition* aParticle);
virtual ~G4DiffuseElastic();
void Initialise();
void InitialiseOnFly(G4double Z, G4double A);
void BuildAngleTable();
G4HadFinalState * ApplyYourself(const G4HadProjectile & aTrack,
G4Nucleus & targetNucleus);
void SetPlabLowLimit(G4double value);
void SetHEModelLowLimit(G4double value);
void SetQModelLowLimit(G4double value);
void SetLowestEnergyLimit(G4double value);
void SetRecoilKinEnergyLimit(G4double value);
G4double SampleT(const G4ParticleDefinition* aParticle,
G4double p, G4double A);
G4double SampleTableT(const G4ParticleDefinition* aParticle,
G4double p, G4double Z, G4double A);
G4double SampleThetaCMS(const G4ParticleDefinition* aParticle, G4double p, G4double A);
G4double SampleTableThetaCMS(const G4ParticleDefinition* aParticle, G4double p,
G4double Z, G4double A);
G4double GetScatteringAngle(G4int iMomentum, G4int iAngle, G4double position);
G4double SampleThetaLab(const G4HadProjectile* aParticle,
G4double tmass, G4double A);
G4double GetDiffuseElasticXsc( const G4ParticleDefinition* particle,
G4double theta,
G4double momentum,
G4double A );
G4double GetInvElasticXsc( const G4ParticleDefinition* particle,
G4double theta,
G4double momentum,
G4double A, G4double Z );
G4double GetDiffuseElasticSumXsc( const G4ParticleDefinition* particle,
G4double theta,
G4double momentum,
G4double A, G4double Z );
G4double GetInvElasticSumXsc( const G4ParticleDefinition* particle,
G4double tMand,
G4double momentum,
G4double A, G4double Z );
G4double IntegralElasticProb( const G4ParticleDefinition* particle,
G4double theta,
G4double momentum,
G4double A );
G4double GetCoulombElasticXsc( const G4ParticleDefinition* particle,
G4double theta,
G4double momentum,
G4double Z );
G4double GetInvCoulombElasticXsc( const G4ParticleDefinition* particle,
G4double tMand,
G4double momentum,
G4double A, G4double Z );
G4double GetCoulombTotalXsc( const G4ParticleDefinition* particle,
G4double momentum, G4double Z );
G4double GetCoulombIntegralXsc( const G4ParticleDefinition* particle,
G4double momentum, G4double Z,
G4double theta1, G4double theta2 );
G4double CalculateParticleBeta( const G4ParticleDefinition* particle,
G4double momentum );
G4double CalculateZommerfeld( G4double beta, G4double Z1, G4double Z2 );
G4double CalculateAm( G4double momentum, G4double n, G4double Z);
G4double CalculateNuclearRad( G4double A);
G4double ThetaCMStoThetaLab(const G4DynamicParticle* aParticle,
G4double tmass, G4double thetaCMS);
G4double ThetaLabToThetaCMS(const G4DynamicParticle* aParticle,
G4double tmass, G4double thetaLab);
G4double BesselJzero(G4double z);
G4double BesselJone(G4double z);
G4double DampFactor(G4double z);
G4double BesselOneByArg(G4double z);
G4double GetDiffElasticProb(G4double theta);
G4double GetDiffElasticSumProb(G4double theta);
G4double GetIntegrandFunction(G4double theta);
G4double GetNuclearRadius(){return fNuclearRadius;};
private:
G4ParticleDefinition* theProton;
G4ParticleDefinition* theNeutron;
G4ParticleDefinition* theDeuteron;
G4ParticleDefinition* theAlpha;
const G4ParticleDefinition* thePionPlus;
const G4ParticleDefinition* thePionMinus;
G4double lowEnergyRecoilLimit;
G4double lowEnergyLimitHE;
G4double lowEnergyLimitQ;
G4double lowestEnergyLimit;
G4double plabLowLimit;
G4int fEnergyBin;
G4int fAngleBin;
G4PhysicsLogVector* fEnergyVector;
G4PhysicsTable* fAngleTable;
std::vector<G4PhysicsTable*> fAngleBank;
std::vector<G4double> fElementNumberVector;
std::vector<G4String> fElementNameVector;
const G4ParticleDefinition* fParticle;
G4double fWaveVector;
G4double fAtomicWeight;
G4double fAtomicNumber;
G4double fNuclearRadius;
G4double fBeta;
G4double fZommerfeld;
G4double fAm;
G4bool fAddCoulomb;
};
inline void G4DiffuseElastic::SetRecoilKinEnergyLimit(G4double value)
{
lowEnergyRecoilLimit = value;
}
inline void G4DiffuseElastic::SetPlabLowLimit(G4double value)
{
plabLowLimit = value;
}
inline void G4DiffuseElastic::SetHEModelLowLimit(G4double value)
{
lowEnergyLimitHE = value;
}
inline void G4DiffuseElastic::SetQModelLowLimit(G4double value)
{
lowEnergyLimitQ = value;
}
inline void G4DiffuseElastic::SetLowestEnergyLimit(G4double value)
{
lowestEnergyLimit = value;
}
/////////////////////////////////////////////////////////////
//
// Bessel J0 function based on rational approximation from
// J.F. Hart, Computer Approximations, New York, Willey 1968, p. 141
inline G4double G4DiffuseElastic::BesselJzero(G4double value)
{
G4double modvalue, value2, fact1, fact2, arg, shift, bessel;
modvalue = fabs(value);
if ( value < 8.0 && value > -8.0 )
{
value2 = value*value;
fact1 = 57568490574.0 + value2*(-13362590354.0
+ value2*( 651619640.7
+ value2*(-11214424.18
+ value2*( 77392.33017
+ value2*(-184.9052456 ) ) ) ) );
fact2 = 57568490411.0 + value2*( 1029532985.0
+ value2*( 9494680.718
+ value2*(59272.64853
+ value2*(267.8532712
+ value2*1.0 ) ) ) );
bessel = fact1/fact2;
}
else
{
arg = 8.0/modvalue;
value2 = arg*arg;
shift = modvalue-0.785398164;
fact1 = 1.0 + value2*(-0.1098628627e-2
+ value2*(0.2734510407e-4
+ value2*(-0.2073370639e-5
+ value2*0.2093887211e-6 ) ) );
fact2 = -0.1562499995e-1 + value2*(0.1430488765e-3
+ value2*(-0.6911147651e-5
+ value2*(0.7621095161e-6
- value2*0.934945152e-7 ) ) );
bessel = sqrt(0.636619772/modvalue)*(cos(shift)*fact1 - arg*sin(shift)*fact2 );
}
return bessel;
}
/////////////////////////////////////////////////////////////
//
// Bessel J1 function based on rational approximation from
// J.F. Hart, Computer Approximations, New York, Willey 1968, p. 141
inline G4double G4DiffuseElastic::BesselJone(G4double value)
{
G4double modvalue, value2, fact1, fact2, arg, shift, bessel;
modvalue = fabs(value);
if ( modvalue < 8.0 )
{
value2 = value*value;
fact1 = value*(72362614232.0 + value2*(-7895059235.0
+ value2*( 242396853.1
+ value2*(-2972611.439
+ value2*( 15704.48260
+ value2*(-30.16036606 ) ) ) ) ) );
fact2 = 144725228442.0 + value2*(2300535178.0
+ value2*(18583304.74
+ value2*(99447.43394
+ value2*(376.9991397
+ value2*1.0 ) ) ) );
bessel = fact1/fact2;
}
else
{
arg = 8.0/modvalue;
value2 = arg*arg;
shift = modvalue - 2.356194491;
fact1 = 1.0 + value2*( 0.183105e-2
+ value2*(-0.3516396496e-4
+ value2*(0.2457520174e-5
+ value2*(-0.240337019e-6 ) ) ) );
fact2 = 0.04687499995 + value2*(-0.2002690873e-3
+ value2*( 0.8449199096e-5
+ value2*(-0.88228987e-6
+ value2*0.105787412e-6 ) ) );
bessel = sqrt( 0.636619772/modvalue)*(cos(shift)*fact1 - arg*sin(shift)*fact2);
if (value < 0.0) bessel = -bessel;
}
return bessel;
}
////////////////////////////////////////////////////////////////////
//
// damp factor in diffraction x/sh(x), x was already *pi
inline G4double G4DiffuseElastic::DampFactor(G4double x)
{
G4double df;
G4double f2 = 2., f3 = 6., f4 = 24.; // first factorials
// x *= pi;
if( std::fabs(x) < 0.01 )
{
df = 1./(1. + x/f2 + x*x/f3 + x*x*x/f4);
}
else
{
df = x/std::sinh(x);
}
return df;
}
////////////////////////////////////////////////////////////////////
//
// return J1(x)/x with special case for small x
inline G4double G4DiffuseElastic::BesselOneByArg(G4double x)
{
G4double x2, result;
if( std::fabs(x) < 0.01 )
{
x *= 0.5;
x2 = x*x;
result = 2. - x2 + x2*x2/6.;
}
else
{
result = BesselJone(x)/x;
}
return result;
}
////////////////////////////////////////////////////////////////////
//
// return particle beta
inline G4double G4DiffuseElastic::CalculateParticleBeta( const G4ParticleDefinition* particle,
G4double momentum )
{
G4double mass = particle->GetPDGMass();
G4double a = momentum/mass;
fBeta = a/std::sqrt(1+a*a);
return fBeta;
}
////////////////////////////////////////////////////////////////////
//
// return Zommerfeld parameter for Coulomb scattering
inline G4double G4DiffuseElastic::CalculateZommerfeld( G4double beta, G4double Z1, G4double Z2 )
{
fZommerfeld = fine_structure_const*Z1*Z2/beta;
return fZommerfeld;
}
////////////////////////////////////////////////////////////////////
//
// return Wentzel correction for Coulomb scattering
inline G4double G4DiffuseElastic::CalculateAm( G4double momentum, G4double n, G4double Z)
{
G4double k = momentum/hbarc;
G4double ch = 1.13 + 3.76*n*n;
G4double zn = 1.77*k*std::pow(Z,-1./3.)*Bohr_radius;
G4double zn2 = zn*zn;
fAm = ch/zn2;
return fAm;
}
////////////////////////////////////////////////////////////////////
//
// calculate nuclear radius for different atomic weights using different approximations
inline G4double G4DiffuseElastic::CalculateNuclearRad( G4double A)
{
G4double r0;
if(A < 50.)
{
if(A > 10.) r0 = 1.16*( 1 - std::pow(A, -2./3.) )*fermi; // 1.08*fermi;
else r0 = 1.1*fermi;
fNuclearRadius = r0*std::pow(A, 1./3.);
}
else
{
r0 = 1.7*fermi;
fNuclearRadius = r0*std::pow(A, 0.27);
}
return fNuclearRadius;
}
////////////////////////////////////////////////////////////////////
//
// return Coulomb scattering differential xsc with Wentzel correction
inline G4double G4DiffuseElastic::GetCoulombElasticXsc( const G4ParticleDefinition* particle,
G4double theta,
G4double momentum,
G4double Z )
{
G4double sinHalfTheta = std::sin(0.5*theta);
G4double sinHalfTheta2 = sinHalfTheta*sinHalfTheta;
G4double beta = CalculateParticleBeta( particle, momentum);
G4double z = particle->GetPDGCharge();
G4double n = CalculateZommerfeld( beta, z, Z );
G4double am = CalculateAm( momentum, n, Z);
G4double k = momentum/hbarc;
G4double ch = 0.5*n/k;
G4double ch2 = ch*ch;
G4double xsc = ch2/(sinHalfTheta2+am)/(sinHalfTheta2+am);
return xsc;
}
////////////////////////////////////////////////////////////////////
//
// return Coulomb scattering total xsc with Wentzel correction
inline G4double G4DiffuseElastic::GetCoulombTotalXsc( const G4ParticleDefinition* particle,
G4double momentum, G4double Z )
{
G4double beta = CalculateParticleBeta( particle, momentum);
G4cout<<"beta = "<<beta<<G4endl;
G4double z = particle->GetPDGCharge();
G4double n = CalculateZommerfeld( beta, z, Z );
G4cout<<"fZomerfeld = "<<n<<G4endl;
G4double am = CalculateAm( momentum, n, Z);
G4cout<<"cof Am = "<<am<<G4endl;
G4double k = momentum/hbarc;
G4cout<<"k = "<<k*fermi<<" 1/fermi"<<G4endl;
G4cout<<"k*Bohr_radius = "<<k*Bohr_radius<<G4endl;
G4double ch = n/k;
G4double ch2 = ch*ch;
G4double xsc = ch2*pi/(am +am*am);
return xsc;
}
////////////////////////////////////////////////////////////////////
//
// return Coulomb scattering xsc with Wentzel correction integrated between
// theta1 and < theta2
inline G4double G4DiffuseElastic::GetCoulombIntegralXsc( const G4ParticleDefinition* particle,
G4double momentum, G4double Z,
G4double theta1, G4double theta2 )
{
G4double c1 = std::cos(theta1);
G4cout<<"c1 = "<<c1<<G4endl;
G4double c2 = std::cos(theta2);
G4cout<<"c2 = "<<c2<<G4endl;
G4double beta = CalculateParticleBeta( particle, momentum);
// G4cout<<"beta = "<<beta<<G4endl;
G4double z = particle->GetPDGCharge();
G4double n = CalculateZommerfeld( beta, z, Z );
// G4cout<<"fZomerfeld = "<<n<<G4endl;
G4double am = CalculateAm( momentum, n, Z);
// G4cout<<"cof Am = "<<am<<G4endl;
G4double k = momentum/hbarc;
// G4cout<<"k = "<<k*fermi<<" 1/fermi"<<G4endl;
// G4cout<<"k*Bohr_radius = "<<k*Bohr_radius<<G4endl;
G4double ch = n/k;
G4double ch2 = ch*ch;
am *= 2.;
G4double xsc = ch2*twopi*(c1-c2);
xsc /= (1 - c1 + am)*(1 - c2 + am);
return xsc;
}
#endif
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