#include <G4UrbanMscModel93.hh>

Inheritance diagram for G4UrbanMscModel93:

Public Member Functions
	G4UrbanMscModel93 (const G4String &nam="UrbanMsc93")

virtual	~G4UrbanMscModel93 ()

void	Initialise (const G4ParticleDefinition *, const G4DataVector &)

void	StartTracking (G4Track *)

G4double	ComputeCrossSectionPerAtom (const G4ParticleDefinition *particle, G4double KineticEnergy, G4double AtomicNumber, G4double AtomicWeight=0., G4double cut=0., G4double emax=DBL_MAX)

G4ThreeVector &	SampleScattering (const G4DynamicParticle *, G4double safety)

G4double	ComputeTruePathLengthLimit (const G4Track &track, G4double &currentMinimalStep)

G4double	ComputeGeomPathLength (G4double truePathLength)

G4double	ComputeTrueStepLength (G4double geomStepLength)

G4double	ComputeTheta0 (G4double truePathLength, G4double KineticEnergy)

Public Member Functions inherited from G4VMscModel
	G4VMscModel (const G4String &nam)

virtual	~G4VMscModel ()

virtual G4double	ComputeTruePathLengthLimit (const G4Track &track, G4double &stepLimit)

virtual G4double	ComputeGeomPathLength (G4double truePathLength)

virtual G4double	ComputeTrueStepLength (G4double geomPathLength)

virtual G4ThreeVector &	SampleScattering (const G4DynamicParticle *, G4double safety)

virtual void	SampleSecondaries (std::vector< G4DynamicParticle * > , const G4MaterialCutsCouple , const G4DynamicParticle *, G4double tmin, G4double tmax)

void	SetStepLimitType (G4MscStepLimitType)

void	SetLateralDisplasmentFlag (G4bool val)

void	SetRangeFactor (G4double)

void	SetGeomFactor (G4double)

void	SetSkin (G4double)

void	SetSampleZ (G4bool)

G4VEnergyLossProcess *	GetIonisation () const

void	SetIonisation (G4VEnergyLossProcess , const G4ParticleDefinition part)

G4double	ComputeSafety (const G4ThreeVector &position, G4double limit)

G4double	ComputeGeomLimit (const G4Track &, G4double &presafety, G4double limit)

G4double	GetDEDX (const G4ParticleDefinition part, G4double kineticEnergy, const G4MaterialCutsCouple couple)

G4double	GetRange (const G4ParticleDefinition part, G4double kineticEnergy, const G4MaterialCutsCouple couple)

G4double	GetEnergy (const G4ParticleDefinition part, G4double range, const G4MaterialCutsCouple couple)

G4double	GetTransportMeanFreePath (const G4ParticleDefinition *part, G4double kinEnergy)

Public Member Functions inherited from G4VEmModel
	G4VEmModel (const G4String &nam)

virtual	~G4VEmModel ()

virtual void	Initialise (const G4ParticleDefinition *, const G4DataVector &)=0

virtual void	SampleSecondaries (std::vector< G4DynamicParticle * > , const G4MaterialCutsCouple , const G4DynamicParticle *, G4double tmin=0.0, G4double tmax=DBL_MAX)=0

virtual G4double	ComputeDEDXPerVolume (const G4Material , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=DBL_MAX)

virtual G4double	CrossSectionPerVolume (const G4Material , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

virtual G4double	ComputeCrossSectionPerAtom (const G4ParticleDefinition *, G4double kinEnergy, G4double Z, G4double A=0., G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

virtual G4double	ChargeSquareRatio (const G4Track &)

virtual G4double	GetChargeSquareRatio (const G4ParticleDefinition , const G4Material , G4double kineticEnergy)

virtual G4double	GetParticleCharge (const G4ParticleDefinition , const G4Material , G4double kineticEnergy)

virtual void	StartTracking (G4Track *)

virtual void	CorrectionsAlongStep (const G4MaterialCutsCouple , const G4DynamicParticle , G4double &eloss, G4double &niel, G4double length)

virtual G4double	Value (const G4MaterialCutsCouple , const G4ParticleDefinition , G4double kineticEnergy)

virtual G4double	MinPrimaryEnergy (const G4Material , const G4ParticleDefinition )

virtual void	SetupForMaterial (const G4ParticleDefinition , const G4Material , G4double kineticEnergy)

virtual void	DefineForRegion (const G4Region *)

void	InitialiseElementSelectors (const G4ParticleDefinition *, const G4DataVector &)

G4double	ComputeDEDX (const G4MaterialCutsCouple , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=DBL_MAX)

G4double	CrossSection (const G4MaterialCutsCouple , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

G4double	ComputeMeanFreePath (const G4ParticleDefinition , G4double kineticEnergy, const G4Material , G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

G4double	ComputeCrossSectionPerAtom (const G4ParticleDefinition , const G4Element , G4double kinEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

G4int	SelectIsotopeNumber (const G4Element *)

const G4Element *	SelectRandomAtom (const G4MaterialCutsCouple , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

const G4Element *	SelectRandomAtom (const G4Material , const G4ParticleDefinition , G4double kineticEnergy, G4double cutEnergy=0.0, G4double maxEnergy=DBL_MAX)

void	SetParticleChange (G4VParticleChange , G4VEmFluctuationModel f=0)

void	SetCrossSectionTable (G4PhysicsTable *)

G4PhysicsTable *	GetCrossSectionTable ()

G4VEmFluctuationModel *	GetModelOfFluctuations ()

G4VEmAngularDistribution *	GetAngularDistribution ()

void	SetAngularDistribution (G4VEmAngularDistribution *)

G4double	HighEnergyLimit () const

G4double	LowEnergyLimit () const

G4double	HighEnergyActivationLimit () const

G4double	LowEnergyActivationLimit () const

G4double	PolarAngleLimit () const

G4double	SecondaryThreshold () const

G4bool	LPMFlag () const

G4bool	DeexcitationFlag () const

G4bool	ForceBuildTableFlag () const

void	SetHighEnergyLimit (G4double)

void	SetLowEnergyLimit (G4double)

void	SetActivationHighEnergyLimit (G4double)

void	SetActivationLowEnergyLimit (G4double)

G4bool	IsActive (G4double kinEnergy)

void	SetPolarAngleLimit (G4double)

void	SetSecondaryThreshold (G4double)

void	SetLPMFlag (G4bool val)

void	SetDeexcitationFlag (G4bool val)

void	ForceBuildTable (G4bool val)

G4double	MaxSecondaryKinEnergy (const G4DynamicParticle *dynParticle)

const G4String &	GetName () const

void	SetCurrentCouple (const G4MaterialCutsCouple *)

const G4Element *	GetCurrentElement () const

Additional Inherited Members
Protected Member Functions inherited from G4VMscModel
G4ParticleChangeForMSC *	GetParticleChangeForMSC (const G4ParticleDefinition *p=0)

G4double	ConvertTrueToGeom (G4double &tLength, G4double &gLength)

Protected Member Functions inherited from G4VEmModel
G4ParticleChangeForLoss *	GetParticleChangeForLoss ()

G4ParticleChangeForGamma *	GetParticleChangeForGamma ()

virtual G4double	MaxSecondaryEnergy (const G4ParticleDefinition *, G4double kineticEnergy)

const G4MaterialCutsCouple *	CurrentCouple () const

void	SetCurrentElement (const G4Element *)

Protected Attributes inherited from G4VMscModel
G4double	facrange

G4double	facgeom

G4double	facsafety

G4double	skin

G4double	dtrl

G4double	lambdalimit

G4double	geomMin

G4double	geomMax

G4ThreeVector	fDisplacement

G4MscStepLimitType	steppingAlgorithm

G4bool	samplez

G4bool	latDisplasment

Protected Attributes inherited from G4VEmModel
G4VParticleChange *	pParticleChange

G4PhysicsTable *	xSectionTable

const std::vector< G4double > *	theDensityFactor

const std::vector< G4int > *	theDensityIdx

Detailed Description

Definition at line 71 of file G4UrbanMscModel93.hh.

Constructor & Destructor Documentation

◆ G4UrbanMscModel93()

G4UrbanMscModel93::G4UrbanMscModel93 ( const G4String & nam = "UrbanMsc93" )

Definition at line 119 of file G4UrbanMscModel93.cc.

  : G4VMscModel(nam)
{
  masslimite    = 0.6*MeV;
  lambdalimit   = 1.*mm;
  fr            = 0.02;
  taubig        = 8.0;
  tausmall      = 1.e-16;
  taulim        = 1.e-6;
  currentTau    = taulim;
  tlimitminfix  = 1.e-6*mm;            
  stepmin       = tlimitminfix;
  smallstep     = 1.e10;
  currentRange  = 0. ;
  rangeinit     = 0.;
  tlimit        = 1.e10*mm;
  tlimitmin     = 10.*tlimitminfix;            
  tgeom         = 1.e50*mm;
  geombig       = 1.e50*mm;
  geommin       = 1.e-3*mm;
  geomlimit     = geombig;
  presafety     = 0.*mm;
                          
  y             = 0.;
 
  Zold          = 0.;
  Zeff          = 1.;
  Z2            = 1.;                
  Z23           = 1.;                    
  lnZ           = 0.;
  coeffth1      = 0.;
  coeffth2      = 0.;
  coeffc1       = 0.;
  coeffc2       = 0.;
  scr1ini       = fine_structure_const*fine_structure_const*
                  electron_mass_c2*electron_mass_c2/(0.885*0.885*4.*pi);
  scr2ini       = 3.76*fine_structure_const*fine_structure_const;
  scr1          = 0.;
  scr2          = 0.;
 
  theta0max     = pi/6.;
  rellossmax    = 0.50;
  third         = 1./3.;
  particle      = 0;
  theManager    = G4LossTableManager::Instance(); 
  firstStep     = true; 
  inside        = false;  
  insideskin    = false;
 
  skindepth = skin*stepmin;
 
  mass = proton_mass_c2;
  charge = ChargeSquare = 1.0;
  currentKinEnergy = currentRadLength = lambda0 = lambdaeff = tPathLength 
    = zPathLength = par1 = par2 = par3 = 0;
 
  currentMaterialIndex = -1;
  fParticleChange = 0;
  couple = 0;
}

◆ ~G4UrbanMscModel93()

G4UrbanMscModel93::~G4UrbanMscModel93 ( )

virtual

Definition at line 182 of file G4UrbanMscModel93.cc.

183{}

Member Function Documentation

◆ ComputeCrossSectionPerAtom()

G4double G4UrbanMscModel93::ComputeCrossSectionPerAtom	(	const G4ParticleDefinition *	particle,
		G4double	KineticEnergy,
		G4double	AtomicNumber,
		G4double	AtomicWeight = `0.`,
		G4double	cut = `0.`,
		G4double	emax = `DBL_MAX`
	)

virtual

Reimplemented from G4VEmModel.

Definition at line 207 of file G4UrbanMscModel93.cc.

{
  const G4double sigmafactor = twopi*classic_electr_radius*classic_electr_radius;
  const G4double epsfactor = 2.*electron_mass_c2*electron_mass_c2*
                            Bohr_radius*Bohr_radius/(hbarc*hbarc);
  const G4double epsmin = 1.e-4 , epsmax = 1.e10;
 
  const G4double Zdat[15] = { 4.,  6., 13., 20., 26., 29., 32., 38., 47.,
                             50., 56., 64., 74., 79., 82. };
 
  const G4double Tdat[22] = { 100*eV,  200*eV,  400*eV,  700*eV,
                               1*keV,   2*keV,   4*keV,   7*keV,
                  10*keV,  20*keV,  40*keV,  70*keV,
                             100*keV, 200*keV, 400*keV, 700*keV,
                               1*MeV,   2*MeV,   4*MeV,   7*MeV,
                  10*MeV,  20*MeV};
 
  // corr. factors for e-/e+ lambda for T <= Tlim
          G4double celectron[15][22] =
          {{1.125,1.072,1.051,1.047,1.047,1.050,1.052,1.054,
            1.054,1.057,1.062,1.069,1.075,1.090,1.105,1.111,
            1.112,1.108,1.100,1.093,1.089,1.087            },
           {1.408,1.246,1.143,1.096,1.077,1.059,1.053,1.051,
            1.052,1.053,1.058,1.065,1.072,1.087,1.101,1.108,
            1.109,1.105,1.097,1.090,1.086,1.082            },
           {2.833,2.268,1.861,1.612,1.486,1.309,1.204,1.156,
            1.136,1.114,1.106,1.106,1.109,1.119,1.129,1.132,
            1.131,1.124,1.113,1.104,1.099,1.098            },
           {3.879,3.016,2.380,2.007,1.818,1.535,1.340,1.236,
            1.190,1.133,1.107,1.099,1.098,1.103,1.110,1.113,
            1.112,1.105,1.096,1.089,1.085,1.098            },
           {6.937,4.330,2.886,2.256,1.987,1.628,1.395,1.265,
            1.203,1.122,1.080,1.065,1.061,1.063,1.070,1.073,
            1.073,1.070,1.064,1.059,1.056,1.056            },
           {9.616,5.708,3.424,2.551,2.204,1.762,1.485,1.330,
            1.256,1.155,1.099,1.077,1.070,1.068,1.072,1.074,
            1.074,1.070,1.063,1.059,1.056,1.052            },
           {11.72,6.364,3.811,2.806,2.401,1.884,1.564,1.386,
            1.300,1.180,1.112,1.082,1.073,1.066,1.068,1.069,
            1.068,1.064,1.059,1.054,1.051,1.050            },
           {18.08,8.601,4.569,3.183,2.662,2.025,1.646,1.439,
            1.339,1.195,1.108,1.068,1.053,1.040,1.039,1.039,
            1.039,1.037,1.034,1.031,1.030,1.036            },
           {18.22,10.48,5.333,3.713,3.115,2.367,1.898,1.631,
            1.498,1.301,1.171,1.105,1.077,1.048,1.036,1.033,
            1.031,1.028,1.024,1.022,1.021,1.024            },
           {14.14,10.65,5.710,3.929,3.266,2.453,1.951,1.669,
            1.528,1.319,1.178,1.106,1.075,1.040,1.027,1.022,
            1.020,1.017,1.015,1.013,1.013,1.020            },
           {14.11,11.73,6.312,4.240,3.478,2.566,2.022,1.720,
            1.569,1.342,1.186,1.102,1.065,1.022,1.003,0.997,
            0.995,0.993,0.993,0.993,0.993,1.011            },
           {22.76,20.01,8.835,5.287,4.144,2.901,2.219,1.855,
            1.677,1.410,1.224,1.121,1.073,1.014,0.986,0.976,
            0.974,0.972,0.973,0.974,0.975,0.987            },
           {50.77,40.85,14.13,7.184,5.284,3.435,2.520,2.059,
            1.837,1.512,1.283,1.153,1.091,1.010,0.969,0.954,
            0.950,0.947,0.949,0.952,0.954,0.963            },
           {65.87,59.06,15.87,7.570,5.567,3.650,2.682,2.182,
            1.939,1.579,1.325,1.178,1.108,1.014,0.965,0.947,
            0.941,0.938,0.940,0.944,0.946,0.954            },
           {55.60,47.34,15.92,7.810,5.755,3.767,2.760,2.239,
            1.985,1.609,1.343,1.188,1.113,1.013,0.960,0.939,
            0.933,0.930,0.933,0.936,0.939,0.949            }};
        
           G4double cpositron[15][22] = {
           {2.589,2.044,1.658,1.446,1.347,1.217,1.144,1.110,
            1.097,1.083,1.080,1.086,1.092,1.108,1.123,1.131,
            1.131,1.126,1.117,1.108,1.103,1.100            },
           {3.904,2.794,2.079,1.710,1.543,1.325,1.202,1.145,
            1.122,1.096,1.089,1.092,1.098,1.114,1.130,1.137,
            1.138,1.132,1.122,1.113,1.108,1.102            },
           {7.970,6.080,4.442,3.398,2.872,2.127,1.672,1.451,
            1.357,1.246,1.194,1.179,1.178,1.188,1.201,1.205,
            1.203,1.190,1.173,1.159,1.151,1.145            },
           {9.714,7.607,5.747,4.493,3.815,2.777,2.079,1.715,
            1.553,1.353,1.253,1.219,1.211,1.214,1.225,1.228,
            1.225,1.210,1.191,1.175,1.166,1.174            },
           {17.97,12.95,8.628,6.065,4.849,3.222,2.275,1.820,
            1.624,1.382,1.259,1.214,1.202,1.202,1.214,1.219,
            1.217,1.203,1.184,1.169,1.160,1.151            },
           {24.83,17.06,10.84,7.355,5.767,3.707,2.546,1.996,
            1.759,1.465,1.311,1.252,1.234,1.228,1.238,1.241,
            1.237,1.222,1.201,1.184,1.174,1.159            },
           {23.26,17.15,11.52,8.049,6.375,4.114,2.792,2.155,
            1.880,1.535,1.353,1.281,1.258,1.247,1.254,1.256,
            1.252,1.234,1.212,1.194,1.183,1.170            },
           {22.33,18.01,12.86,9.212,7.336,4.702,3.117,2.348,
            2.015,1.602,1.385,1.297,1.268,1.251,1.256,1.258,
            1.254,1.237,1.214,1.195,1.185,1.179            },
           {33.91,24.13,15.71,10.80,8.507,5.467,3.692,2.808,
            2.407,1.873,1.564,1.425,1.374,1.330,1.324,1.320,
            1.312,1.288,1.258,1.235,1.221,1.205            },
           {32.14,24.11,16.30,11.40,9.015,5.782,3.868,2.917,
            2.490,1.925,1.596,1.447,1.391,1.342,1.332,1.327,
            1.320,1.294,1.264,1.240,1.226,1.214            },
           {29.51,24.07,17.19,12.28,9.766,6.238,4.112,3.066,
            2.602,1.995,1.641,1.477,1.414,1.356,1.342,1.336,
            1.328,1.302,1.270,1.245,1.231,1.233            },
           {38.19,30.85,21.76,15.35,12.07,7.521,4.812,3.498,
            2.926,2.188,1.763,1.563,1.484,1.405,1.382,1.371,
            1.361,1.330,1.294,1.267,1.251,1.239            },
           {49.71,39.80,27.96,19.63,15.36,9.407,5.863,4.155,
            3.417,2.478,1.944,1.692,1.589,1.480,1.441,1.423,
            1.409,1.372,1.330,1.298,1.280,1.258            },
           {59.25,45.08,30.36,20.83,16.15,9.834,6.166,4.407,
            3.641,2.648,2.064,1.779,1.661,1.531,1.482,1.459,
            1.442,1.400,1.354,1.319,1.299,1.272            },
           {56.38,44.29,30.50,21.18,16.51,10.11,6.354,4.542,
            3.752,2.724,2.116,1.817,1.692,1.554,1.499,1.474,
            1.456,1.412,1.364,1.328,1.307,1.282            }};
 
  //data/corrections for T > Tlim  
  G4double Tlim = 10.*MeV;
  G4double beta2lim = Tlim*(Tlim+2.*electron_mass_c2)/
                      ((Tlim+electron_mass_c2)*(Tlim+electron_mass_c2));
  G4double bg2lim   = Tlim*(Tlim+2.*electron_mass_c2)/
                      (electron_mass_c2*electron_mass_c2);
 
  G4double sig0[15] = {0.2672*barn,  0.5922*barn, 2.653*barn,  6.235*barn,
                      11.69*barn  , 13.24*barn  , 16.12*barn, 23.00*barn ,
              35.13*barn  , 39.95*barn  , 50.85*barn, 67.19*barn ,
                      91.15*barn  , 104.4*barn  , 113.1*barn};
                           
  G4double hecorr[15] = {120.70, 117.50, 105.00, 92.92, 79.23,  74.510,  68.29,
                          57.39,  41.97,  36.14, 24.53, 10.21,  -7.855, -16.84,
             -22.30};
 
  G4double sigma;
  SetParticle(part);
 
  Z23 = pow(AtomicNumber,2./3.); 
 
  // correction if particle .ne. e-/e+
  // compute equivalent kinetic energy
  // lambda depends on p*beta ....
 
  G4double eKineticEnergy = KineticEnergy;
 
  if(mass > electron_mass_c2)
  {
     G4double TAU = KineticEnergy/mass ;
     G4double c = mass*TAU*(TAU+2.)/(electron_mass_c2*(TAU+1.)) ;
     G4double w = c-2. ;
     G4double tau = 0.5*(w+sqrt(w*w+4.*c)) ;
     eKineticEnergy = electron_mass_c2*tau ;
  }
 
  G4double eTotalEnergy = eKineticEnergy + electron_mass_c2 ;
  G4double beta2 = eKineticEnergy*(eTotalEnergy+electron_mass_c2)
                                 /(eTotalEnergy*eTotalEnergy);
  G4double bg2   = eKineticEnergy*(eTotalEnergy+electron_mass_c2)
                                 /(electron_mass_c2*electron_mass_c2);
 
  G4double eps = epsfactor*bg2/Z23;
 
  if     (eps<epsmin)  sigma = 2.*eps*eps;
  else if(eps<epsmax)  sigma = log(1.+2.*eps)-2.*eps/(1.+2.*eps);
  else                 sigma = log(2.*eps)-1.+1./eps;
 
  sigma *= ChargeSquare*AtomicNumber*AtomicNumber/(beta2*bg2);
 
  // interpolate in AtomicNumber and beta2 
  G4double c1,c2,cc1,cc2,corr;
 
  // get bin number in Z
  G4int iZ = 14;
  while ((iZ>=0)&&(Zdat[iZ]>=AtomicNumber)) iZ -= 1;
  if (iZ==14)                               iZ = 13;
  if (iZ==-1)                               iZ = 0 ;
 
  G4double ZZ1 = Zdat[iZ];
  G4double ZZ2 = Zdat[iZ+1];
  G4double ratZ = (AtomicNumber-ZZ1)*(AtomicNumber+ZZ1)/
                  ((ZZ2-ZZ1)*(ZZ2+ZZ1));
 
  if(eKineticEnergy <= Tlim) 
  {
    // get bin number in T (beta2)
    G4int iT = 21;
    while ((iT>=0)&&(Tdat[iT]>=eKineticEnergy)) iT -= 1;
    if(iT==21)                                  iT = 20;
    if(iT==-1)                                  iT = 0 ;
 
    //  calculate betasquare values
    G4double T = Tdat[iT],   E = T + electron_mass_c2;
    G4double b2small = T*(E+electron_mass_c2)/(E*E);
 
    T = Tdat[iT+1]; E = T + electron_mass_c2;
    G4double b2big = T*(E+electron_mass_c2)/(E*E);
    G4double ratb2 = (beta2-b2small)/(b2big-b2small);
 
    if (charge < 0.)
    {
       c1 = celectron[iZ][iT];
       c2 = celectron[iZ+1][iT];
       cc1 = c1+ratZ*(c2-c1);
 
       c1 = celectron[iZ][iT+1];
       c2 = celectron[iZ+1][iT+1];
       cc2 = c1+ratZ*(c2-c1);
 
       corr = cc1+ratb2*(cc2-cc1);
 
       sigma *= sigmafactor/corr;
    }
    else              
    {
       c1 = cpositron[iZ][iT];
       c2 = cpositron[iZ+1][iT];
       cc1 = c1+ratZ*(c2-c1);
 
       c1 = cpositron[iZ][iT+1];
       c2 = cpositron[iZ+1][iT+1];
       cc2 = c1+ratZ*(c2-c1);
 
       corr = cc1+ratb2*(cc2-cc1);
 
       sigma *= sigmafactor/corr;
    }
  }
  else
  {
    c1 = bg2lim*sig0[iZ]*(1.+hecorr[iZ]*(beta2-beta2lim))/bg2;
    c2 = bg2lim*sig0[iZ+1]*(1.+hecorr[iZ+1]*(beta2-beta2lim))/bg2;
    if((AtomicNumber >= ZZ1) && (AtomicNumber <= ZZ2))
      sigma = c1+ratZ*(c2-c1) ;
    else if(AtomicNumber < ZZ1)
      sigma = AtomicNumber*AtomicNumber*c1/(ZZ1*ZZ1);
    else if(AtomicNumber > ZZ2)
      sigma = AtomicNumber*AtomicNumber*c2/(ZZ2*ZZ2);
  }
  return sigma;
 
}

◆ ComputeGeomPathLength()

G4double G4UrbanMscModel93::ComputeGeomPathLength ( G4double truePathLength )

virtual

Reimplemented from G4VMscModel.

Definition at line 677 of file G4UrbanMscModel93.cc.

{
  firstStep = false; 
  lambdaeff = lambda0;
  par1 = -1. ;  
  par2 = par3 = 0. ;  
 
  //  do the true -> geom transformation
  zPathLength = tPathLength;
 
  // z = t for very small tPathLength
  if(tPathLength < tlimitminfix) return zPathLength;
 
  // this correction needed to run MSC with eIoni and eBrem inactivated
  // and makes no harm for a normal run
  if(tPathLength > currentRange)
    tPathLength = currentRange ;
 
  G4double tau   = tPathLength/lambda0 ;
 
  if ((tau <= tausmall) || insideskin) {
    zPathLength  = tPathLength;
    if(zPathLength > lambda0) zPathLength = lambda0;
    return zPathLength;
  }
 
  G4double zmean = tPathLength;
  if (tPathLength < currentRange*dtrl) {
    if(tau < taulim) zmean = tPathLength*(1.-0.5*tau) ;
    else             zmean = lambda0*(1.-exp(-tau));
  } else if(currentKinEnergy < mass || tPathLength == currentRange)  {
    par1 = 1./currentRange ;
    par2 = 1./(par1*lambda0) ;
    par3 = 1.+par2 ;
    if(tPathLength < currentRange)
      zmean = (1.-exp(par3*log(1.-tPathLength/currentRange)))/(par1*par3) ;
    else
      zmean = 1./(par1*par3) ;
  } else {
    G4double T1 = GetEnergy(particle,currentRange-tPathLength,couple);
    G4double lambda1 = GetTransportMeanFreePath(particle,T1);
 
    par1 = (lambda0-lambda1)/(lambda0*tPathLength) ;
    par2 = 1./(par1*lambda0) ;
    par3 = 1.+par2 ;
    zmean = (1.-exp(par3*log(lambda1/lambda0)))/(par1*par3) ;
  }
 
  zPathLength = zmean ;
 
  //  sample z
  if(samplez)
  {
    const G4double  ztmax = 0.99 ;
    G4double zt = zmean/tPathLength ;
 
    if (tPathLength > stepmin && zt < ztmax)              
    {
      G4double u,cz1;
      if(zt >= third)
      {
        G4double cz = 0.5*(3.*zt-1.)/(1.-zt) ;
        cz1 = 1.+cz ;
        G4double u0 = cz/cz1 ;
        G4double grej ;
        do {
            u = exp(log(G4UniformRand())/cz1) ;
            grej = exp(cz*log(u/u0))*(1.-u)/(1.-u0) ;
           } while (grej < G4UniformRand()) ;
      }
      else
      {
        cz1 = 1./zt-1.;
        u = 1.-exp(log(G4UniformRand())/cz1) ;
      }
      zPathLength = tPathLength*u ;
    }
  }
 
  if(zPathLength > lambda0) zPathLength = lambda0;
  //G4cout << "zPathLength= " << zPathLength << " lambda1= " << lambda0 << G4endl;
  return zPathLength;
}

◆ ComputeTheta0()

G4double G4UrbanMscModel93::ComputeTheta0	(	G4double	truePathLength,
		G4double	KineticEnergy
	)

Definition at line 796 of file G4UrbanMscModel93.cc.

{
  // for all particles take the width of the central part
  //  from a  parametrization similar to the Highland formula
  // ( Highland formula: Particle Physics Booklet, July 2002, eq. 26.10)
  const G4double c_highland = 13.6*MeV ;
  G4double betacp = sqrt(currentKinEnergy*(currentKinEnergy+2.*mass)*
                         KineticEnergy*(KineticEnergy+2.*mass)/
                      ((currentKinEnergy+mass)*(KineticEnergy+mass)));
  y = trueStepLength/currentRadLength;
  G4double theta0 = c_highland*std::abs(charge)*sqrt(y)/betacp;
  y = log(y);
  // correction factor from e- scattering data
  G4double corr = coeffth1+coeffth2*y;                
 
  theta0 *= corr ;                                               
 
  return theta0;
}

◆ ComputeTruePathLengthLimit()

G4double G4UrbanMscModel93::ComputeTruePathLengthLimit	(	const G4Track &	track,
		G4double &	currentMinimalStep
	)

virtual

Reimplemented from G4VMscModel.

Definition at line 460 of file G4UrbanMscModel93.cc.

{
  tPathLength = currentMinimalStep;
  const G4DynamicParticle* dp = track.GetDynamicParticle();
  G4StepPoint* sp = track.GetStep()->GetPreStepPoint();
  G4StepStatus stepStatus = sp->GetStepStatus();
  couple = track.GetMaterialCutsCouple();
  SetCurrentCouple(couple); 
  currentMaterialIndex = couple->GetIndex();
  currentKinEnergy = dp->GetKineticEnergy();
  currentRange = GetRange(particle,currentKinEnergy,couple);
  lambda0 = GetTransportMeanFreePath(particle,currentKinEnergy);
 
  // stop here if small range particle
  if(inside || tPathLength < tlimitminfix) { 
    return ConvertTrueToGeom(tPathLength, currentMinimalStep); 
  } 
  
  if(tPathLength > currentRange) { tPathLength = currentRange; }
 
  presafety = sp->GetSafety();
 
  // G4cout << "G4Urban2::StepLimit tPathLength= " 
  //     <<tPathLength<<" safety= " << presafety
  //        << " range= " <<currentRange<< " lambda= "<<lambda0
  //     << " Alg: " << steppingAlgorithm <<G4endl;
 
  // far from geometry boundary
  if(currentRange < presafety)
    {
      inside = true;
      return ConvertTrueToGeom(tPathLength, currentMinimalStep);  
    }
 
  // standard  version
  //
  if (steppingAlgorithm == fUseDistanceToBoundary)
    {
      //compute geomlimit and presafety 
      geomlimit = ComputeGeomLimit(track, presafety, currentRange);
 
      // is it far from boundary ?
      if(currentRange < presafety)
    {
      inside = true;
      return ConvertTrueToGeom(tPathLength, currentMinimalStep);   
    }
 
      smallstep += 1.;
      insideskin = false;
 
      if(firstStep || stepStatus == fGeomBoundary)
        {
          rangeinit = currentRange;
          if(firstStep) smallstep = 1.e10;
          else  smallstep = 1.;
 
          //define stepmin here (it depends on lambda!)
          //rough estimation of lambda_elastic/lambda_transport
          G4double rat = currentKinEnergy/MeV ;
          rat = 1.e-3/(rat*(10.+rat)) ;
          //stepmin ~ lambda_elastic
          stepmin = rat*lambda0;
          skindepth = skin*stepmin;
          //define tlimitmin
          tlimitmin = 10.*stepmin;
          if(tlimitmin < tlimitminfix) tlimitmin = tlimitminfix;
      //G4cout << "rangeinit= " << rangeinit << " stepmin= " << stepmin
      //     << " tlimitmin= " << tlimitmin << " geomlimit= " << geomlimit <<G4endl;
          // constraint from the geometry
          if((geomlimit < geombig) && (geomlimit > geommin))
            {
              // geomlimit is a geometrical step length
              // transform it to true path length (estimation)
              if((1.-geomlimit/lambda0) > 0.)
                geomlimit = -lambda0*log(1.-geomlimit/lambda0)+tlimitmin ;
 
              if(stepStatus == fGeomBoundary)
                tgeom = geomlimit/facgeom;
              else
                tgeom = 2.*geomlimit/facgeom;
            }
            else
              tgeom = geombig;
        }
 
 
      //step limit 
      tlimit = facrange*rangeinit;              
      if(tlimit < facsafety*presafety)
        tlimit = facsafety*presafety; 
 
      //lower limit for tlimit
      if(tlimit < tlimitmin) tlimit = tlimitmin;
 
      if(tlimit > tgeom) tlimit = tgeom;
 
      //G4cout << "tgeom= " << tgeom << " geomlimit= " << geomlimit  
      //      << " tlimit= " << tlimit << " presafety= " << presafety << G4endl;
 
      // shortcut
      if((tPathLength < tlimit) && (tPathLength < presafety) &&
         (smallstep >= skin) && (tPathLength < geomlimit-0.999*skindepth))
    return ConvertTrueToGeom(tPathLength, currentMinimalStep);   
 
      // step reduction near to boundary
      if(smallstep < skin)
    {
      tlimit = stepmin;
      insideskin = true;
    }
      else if(geomlimit < geombig)
    {
      if(geomlimit > skindepth)
        {
          if(tlimit > geomlimit-0.999*skindepth)
        tlimit = geomlimit-0.999*skindepth;
        }
      else
        {
          insideskin = true;
          if(tlimit > stepmin) tlimit = stepmin;
        }
    }
 
      if(tlimit < stepmin) tlimit = stepmin;
 
      // randomize 1st step or 1st 'normal' step in volume
      if(firstStep || ((smallstep == skin) && !insideskin)) 
        { 
          G4double temptlimit = tlimit;
          if(temptlimit > tlimitmin)
          {
            do {
              temptlimit = G4RandGauss::shoot(tlimit,0.3*tlimit);        
               } while ((temptlimit < tlimitmin) || 
                        (temptlimit > 2.*tlimit-tlimitmin));
          }
          else
            temptlimit = tlimitmin;
          if(tPathLength > temptlimit) tPathLength = temptlimit;
        }
      else
        {  
          if(tPathLength > tlimit) tPathLength = tlimit  ; 
        }
 
    }
    // for 'normal' simulation with or without magnetic field 
    //  there no small step/single scattering at boundaries
  else if(steppingAlgorithm == fUseSafety)
    {
      // compute presafety again if presafety <= 0 and no boundary
      // i.e. when it is needed for optimization purposes
      if((stepStatus != fGeomBoundary) && (presafety < tlimitminfix)) 
    presafety = ComputeSafety(sp->GetPosition(),tPathLength); 
 
      // is far from boundary
      if(currentRange < presafety)
        {
          inside = true;
          return ConvertTrueToGeom(tPathLength, currentMinimalStep);  
        }
 
      if(firstStep || stepStatus == fGeomBoundary)
      {
        rangeinit = currentRange;
        fr = facrange;
        // 9.1 like stepping for e+/e- only (not for muons,hadrons)
        if(mass < masslimite) 
        {
          if(lambda0 > currentRange)
            rangeinit = lambda0;
          if(lambda0 > lambdalimit)
            fr *= 0.75+0.25*lambda0/lambdalimit;
        }
 
        //lower limit for tlimit
        G4double rat = currentKinEnergy/MeV ;
        rat = 1.e-3/(rat*(10.+rat)) ;
        tlimitmin = 10.*lambda0*rat;
        if(tlimitmin < tlimitminfix) tlimitmin = tlimitminfix;
      }
      //step limit
      tlimit = fr*rangeinit;               
 
      if(tlimit < facsafety*presafety)
        tlimit = facsafety*presafety;
 
      //lower limit for tlimit
      if(tlimit < tlimitmin) tlimit = tlimitmin;
      
      if(tPathLength > tlimit) tPathLength = tlimit;
 
    }
  
  // version similar to 7.1 (needed for some experiments)
  else
    {
      if (stepStatus == fGeomBoundary)
    {
      if (currentRange > lambda0) tlimit = facrange*currentRange;
      else                        tlimit = facrange*lambda0;
 
      if(tlimit < tlimitmin) tlimit = tlimitmin;
      if(tPathLength > tlimit) tPathLength = tlimit;
    }
    }
  //G4cout << "tPathLength= " << tPathLength 
  //     << " currentMinimalStep= " << currentMinimalStep << G4endl;
  return ConvertTrueToGeom(tPathLength, currentMinimalStep);
}

◆ ComputeTrueStepLength()

G4double G4UrbanMscModel93::ComputeTrueStepLength ( G4double geomStepLength )

virtual

Reimplemented from G4VMscModel.

Definition at line 763 of file G4UrbanMscModel93.cc.

{
  // step defined other than transportation 
  if(geomStepLength == zPathLength && tPathLength <= currentRange)
    return tPathLength;
 
  // t = z for very small step
  zPathLength = geomStepLength;
  tPathLength = geomStepLength;
  if(geomStepLength < tlimitminfix) return tPathLength;
  
  // recalculation
  if((geomStepLength > lambda0*tausmall) && !insideskin)
  {
    if(par1 <  0.)
      tPathLength = -lambda0*log(1.-geomStepLength/lambda0) ;
    else 
    {
      if(par1*par3*geomStepLength < 1.)
        tPathLength = (1.-exp(log(1.-par1*par3*geomStepLength)/par3))/par1 ;
      else 
        tPathLength = currentRange;
    }  
  }
  if(tPathLength < geomStepLength) tPathLength = geomStepLength;
 
  //G4cout << "tPathLength= " << tPathLength << " step= " << geomStepLength << G4endl;
 
  return tPathLength;
}

◆ Initialise()

void G4UrbanMscModel93::Initialise	(	const G4ParticleDefinition *	p,
		const G4DataVector &
	)

virtual

Implements G4VEmModel.

Definition at line 187 of file G4UrbanMscModel93.cc.

{
  skindepth = skin*stepmin;
 
  // set values of some data members
  SetParticle(p);
 
  if(p->GetPDGMass() > MeV) {
    G4cout << "### WARNING: G4UrbanMscModel93 model is used for " 
       << p->GetParticleName() << " !!! " << G4endl;
    G4cout << "###          This model should be used only for e+-" 
       << G4endl;
  }
 
  fParticleChange = GetParticleChangeForMSC(p);
}

◆ SampleScattering()

G4ThreeVector & G4UrbanMscModel93::SampleScattering	(	const G4DynamicParticle *	dynParticle,
		G4double	safety
	)

virtual

Reimplemented from G4VMscModel.

Definition at line 820 of file G4UrbanMscModel93.cc.

{
  fDisplacement.set(0.0,0.0,0.0);
  G4double kineticEnergy = currentKinEnergy;
  if (tPathLength > currentRange*dtrl) {
    kineticEnergy = GetEnergy(particle,currentRange-tPathLength,couple);
  } else {
    kineticEnergy -= tPathLength*GetDEDX(particle,currentKinEnergy,couple);
  }
  if((kineticEnergy <= eV) || (tPathLength <= tlimitminfix) ||
     (tPathLength/tausmall < lambda0)) { return  fDisplacement; }
 
  G4double cth  = SampleCosineTheta(tPathLength,kineticEnergy);
 
  // protection against 'bad' cth values
  if(std::fabs(cth) > 1.) { return  fDisplacement; }
 
  // extra protection agaist high energy particles backscattered 
  if(cth < 1.0 - 1000*tPathLength/lambda0 && kineticEnergy > 20*MeV) { 
    //G4cout << "Warning: large scattering E(MeV)= " << kineticEnergy 
    //     << " s(mm)= " << tPathLength/mm
    //     << " 1-cosTheta= " << 1.0 - cth << G4endl;
    // do Gaussian central scattering
    if(kineticEnergy > GeV && cth < 0.0) {
      G4ExceptionDescription ed;
      ed << dynParticle->GetDefinition()->GetParticleName()
     << " E(MeV)= " << kineticEnergy/MeV
     << " Step(mm)= " << tPathLength/mm
     << " in " << CurrentCouple()->GetMaterial()->GetName()
     << " CosTheta= " << cth 
     << " is too big - the angle is resampled" << G4endl;
      G4Exception("G4UrbanMscModel93::SampleScattering","em0004",
          JustWarning, ed,"");
    }
    do {
      cth = 1.0 + 2*log(G4UniformRand())*tPathLength/lambda0;
    } while(cth < -1.0);
  }
 
  G4double sth  = sqrt((1.0 - cth)*(1.0 + cth));
  G4double phi  = twopi*G4UniformRand();
  G4double dirx = sth*cos(phi);
  G4double diry = sth*sin(phi);
 
  G4ThreeVector oldDirection = dynParticle->GetMomentumDirection();
  G4ThreeVector newDirection(dirx,diry,cth);
  newDirection.rotateUz(oldDirection);
  fParticleChange->ProposeMomentumDirection(newDirection);
 
  if (latDisplasment && safety > tlimitminfix) {
 
    G4double r = SampleDisplacement();
    /*    
    G4cout << "G4UrbanMscModel93::SampleSecondaries: e(MeV)= " << kineticEnergy
       << " sinTheta= " << sth << " r(mm)= " << r
           << " trueStep(mm)= " << tPathLength
           << " geomStep(mm)= " << zPathLength
           << G4endl;
    */
    if(r > 0.)
      {
        G4double latcorr = LatCorrelation();
        if(latcorr > r) latcorr = r;
 
        // sample direction of lateral displacement
        // compute it from the lateral correlation
        G4double Phi = 0.;
        if(std::abs(r*sth) < latcorr)
          Phi  = twopi*G4UniformRand();
        else
        {
          G4double psi = std::acos(latcorr/(r*sth));
          if(G4UniformRand() < 0.5)
            Phi = phi+psi;
          else
            Phi = phi-psi;
        }
 
        dirx = r*std::cos(Phi);
        diry = r*std::sin(Phi);
 
    fDisplacement.set(dirx,diry,0.0);
    fDisplacement.rotateUz(oldDirection);
      }
  }
  return fDisplacement;
}

◆ StartTracking()

void G4UrbanMscModel93::StartTracking ( G4Track * track )

virtual

Reimplemented from G4VEmModel.

Definition at line 449 of file G4UrbanMscModel93.cc.

{
  SetParticle(track->GetDynamicParticle()->GetDefinition());
  firstStep = true; 
  inside = false;
  insideskin = false;
  tlimit = geombig;
}

The documentation for this class was generated from the following files:

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ G4UrbanMscModel93()

◆ ~G4UrbanMscModel93()

Member Function Documentation

◆ ComputeCrossSectionPerAtom()

◆ ComputeGeomPathLength()

◆ ComputeTheta0()

◆ ComputeTruePathLengthLimit()

◆ ComputeTrueStepLength()

◆ Initialise()

◆ SampleScattering()

◆ StartTracking()