#include <G4UrbanMscModel.hh>

Inheritance diagram for G4UrbanMscModel:

Public Member Functions
	G4UrbanMscModel (const G4String &nam="UrbanMsc")

virtual	~G4UrbanMscModel ()

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 G4ThreeVector &, 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 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	InitialiseLocal (const G4ParticleDefinition , G4VEmModel masterModel)

virtual void	InitialiseForMaterial (const G4ParticleDefinition , const G4Material )

virtual void	InitialiseForElement (const G4ParticleDefinition *, G4int Z)

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	ChargeSquareRatio (const G4Track &)

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

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

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 , G4double cut=0.0)

virtual G4double	MinEnergyCut (const G4ParticleDefinition , const G4MaterialCutsCouple )

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

virtual void	DefineForRegion (const G4Region *)

void	InitialiseElementSelectors (const G4ParticleDefinition *, const G4DataVector &)

std::vector < G4EmElementSelector * > *	GetElementSelectors ()

void	SetElementSelectors (std::vector< G4EmElementSelector * > *)

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)

G4int	SelectRandomAtomNumber (const G4Material *)

void	SetParticleChange (G4VParticleChange , G4VEmFluctuationModel f=0)

void	SetCrossSectionTable (G4PhysicsTable *, G4bool isLocal)

G4ElementData *	GetElementData ()

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

G4bool	UseAngularGeneratorFlag () const

void	SetAngularGeneratorFlag (G4bool)

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	SetForceBuildTable (G4bool val)

void	SetMasterThread (G4bool val)

G4bool	IsMaster () const

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
G4ElementData *	fElementData

G4VParticleChange *	pParticleChange

G4PhysicsTable *	xSectionTable

const std::vector< G4double > *	theDensityFactor

const std::vector< G4int > *	theDensityIdx

size_t	idxTable

Detailed Description

Definition at line 74 of file G4UrbanMscModel.hh.

Constructor & Destructor Documentation

G4UrbanMscModel::G4UrbanMscModel ( const G4String & nam = "UrbanMsc" )

Definition at line 104 of file G4UrbanMscModel.cc.

References G4LossTableManager::Instance(), python.hepunit::MeV, python.hepunit::mm, python.hepunit::pi, python.hepunit::proton_mass_c2, G4VMscModel::SetSampleZ(), and G4VMscModel::skin.

   : 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  = 0.01*nm;             
   tlimitminfix2 =   1.*nm;             
   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.;
   coeffc3       = 0.;
   coeffc4       = 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;
   SetSampleZ(true);
 }

G4UrbanMscModel::~G4UrbanMscModel ( )

virtual

Definition at line 166 of file G4UrbanMscModel.cc.

167 {}

Member Function Documentation

G4double G4UrbanMscModel::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 195 of file G4UrbanMscModel.cc.

References test::c, plottest35::c1, python.hepunit::electron_mass_c2, G4Log(), G4lrint(), G4Pow::GetInstance(), and G4Pow::Z23().

 {
   static const G4double epsmin = 1.e-4 , epsmax = 1.e10;
 
   static const G4double Zdat[15] = { 4.,  6., 13., 20., 26., 29., 32., 38.,47.,
                      50., 56., 64., 74., 79., 82. };
 
   // corr. factors for e-/e+ lambda for T <= Tlim
   static const 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            }};
         
   static const 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  
                            
   static const 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 = G4Pow::GetInstance()->Z23(G4lrint(AtomicNumber));
 
   // 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 = G4Log(1.+2.*eps)-2.*eps/(1.+2.*eps);
   else                 sigma = G4Log(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;
 
 }

G4double G4UrbanMscModel::ComputeGeomPathLength ( G4double truePathLength )

virtual

Reimplemented from G4VMscModel.

Definition at line 685 of file G4UrbanMscModel.cc.

References G4VMscModel::dtrl, G4Exp(), G4Log(), G4VMscModel::GetEnergy(), and G4VMscModel::GetTransportMeanFreePath().

 {
   firstStep = false; 
   lambdaeff = lambda0;
   par1 = -1. ;  
   par2 = par3 = 0. ;  
 
   //  do the true -> geom transformation
   zPathLength = tPathLength;
 
   // z = t for very small tPathLength
   if(tPathLength < tlimitminfix2) return zPathLength;
 
   // this correction needed to run MSC with eIoni and eBrem inactivated
   // and makes no harm for a normal run
   // It is already checked
   // 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.-G4Exp(-tau));
     zPathLength = zmean ;
     return zPathLength;    
 
   } else if(currentKinEnergy < mass || tPathLength == currentRange)  {
     par1 = 1./currentRange ;
     par2 = 1./(par1*lambda0) ;
     par3 = 1.+par2 ;
     if(tPathLength < currentRange)
       zmean = (1.-G4Exp(par3*G4Log(1.-tPathLength/currentRange)))/(par1*par3) ;
     else {
       zmean = 1./(par1*par3) ;
     }
     zPathLength = zmean ;
     return zPathLength;    
 
   } 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.-G4Exp(par3*G4Log(lambda1/lambda0)))/(par1*par3);
   }
 
   zPathLength = zmean;
 
   if(zPathLength > lambda0) { zPathLength = lambda0; }
   //G4cout<< "zPathLength= "<< zPathLength<< " lambda1= " << lambda0 << G4endl;
   return zPathLength;
 }

G4double G4UrbanMscModel::ComputeTheta0	(	G4double	truePathLength,
		G4double	KineticEnergy
	)

inline

Definition at line 222 of file G4UrbanMscModel.hh.

References G4Log().

 {
   // 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)
   G4double invbetacp = sqrt((currentKinEnergy+mass)*(KineticEnergy+mass)/
                 (currentKinEnergy*(currentKinEnergy+2.*mass)*
                  KineticEnergy*(KineticEnergy+2.*mass)));
   y = trueStepLength/currentRadLength;
   G4double theta0 = c_highland*std::abs(charge)*sqrt(y)*invbetacp;
   y = G4Log(y);
   // correction factor from e- scattering data
   theta0 *= (coeffth1+coeffth2*y);
   return theta0;
 }

G4double G4UrbanMscModel::ComputeTruePathLengthLimit	(	const G4Track &	track,
		G4double &	currentMinimalStep
	)

virtual

Reimplemented from G4VMscModel.

Definition at line 431 of file G4UrbanMscModel.cc.

References G4VMscModel::ComputeGeomLimit(), G4VMscModel::ComputeSafety(), G4VMscModel::ConvertTrueToGeom(), G4VMscModel::facgeom, G4VMscModel::facrange, G4VMscModel::facsafety, fGeomBoundary, fUseDistanceToBoundary, fUseSafety, G4Log(), G4Track::GetDynamicParticle(), G4MaterialCutsCouple::GetIndex(), G4DynamicParticle::GetKineticEnergy(), G4Track::GetMaterialCutsCouple(), G4StepPoint::GetPosition(), G4Step::GetPreStepPoint(), G4VMscModel::GetRange(), G4StepPoint::GetSafety(), G4Track::GetStep(), G4StepPoint::GetStepStatus(), G4VMscModel::GetTransportMeanFreePath(), python.hepunit::MeV, G4VEmModel::SetCurrentCouple(), G4INCL::DeJongSpin::shoot(), G4VMscModel::skin, G4InuclParticleNames::sp, and G4VMscModel::steppingAlgorithm.

 {
   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);
   if(tPathLength > currentRange) { tPathLength = currentRange; }
 
   // stop here if small range particle
   if(inside || tPathLength < tlimitminfix) { 
     return ConvertTrueToGeom(tPathLength, currentMinimalStep); 
   }
   
   presafety = sp->GetSafety();
   /*
   G4cout << "G4Urban96::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*G4Log(1.-geomlimit/lambda0)+tlimitmin ;
 
               if(stepStatus == fGeomBoundary)
                 tgeom = geomlimit/facgeom;
               else
                 tgeom = 2.*geomlimit/facgeom;
             }
             else
               tgeom = geombig;
         }
 
 
       //step limit 
       tlimit = facrange*rangeinit;              
 
       //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+1) && !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); 
       /*
       G4cout << "presafety= " << presafety
          << " firstStep= " << firstStep
          << " stepStatus= " << stepStatus 
          << G4endl;
       */
       // 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)) ;
         stepmin = lambda0*rat;
         tlimitmin = 10.*stepmin;
         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(firstStep || stepStatus == fGeomBoundary)
       {
         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;
 
     }
   
   // 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(firstStep || stepStatus == fGeomBoundary)
       {
         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;
     }
   //G4cout << "tPathLength= " << tPathLength 
   //     << " currentMinimalStep= " << currentMinimalStep << G4endl;
   return ConvertTrueToGeom(tPathLength, currentMinimalStep);
 }

G4double G4UrbanMscModel::ComputeTrueStepLength ( G4double geomStepLength )

virtual

Reimplemented from G4VMscModel.

Definition at line 750 of file G4UrbanMscModel.cc.

References G4Exp(), and G4Log().

 {
   // step defined other than transportation 
   if(geomStepLength == zPathLength)
     { return tPathLength; }
 
   zPathLength = geomStepLength;
 
   // t = z for very small step
   if(geomStepLength < tlimitminfix2) { 
     tPathLength = geomStepLength; 
   
   // recalculation
   } else {
 
     G4double tlength = geomStepLength;
     if((geomStepLength > lambda0*tausmall) && !insideskin) {
 
       if(par1 <  0.) {
     tlength = -lambda0*G4Log(1.-geomStepLength/lambda0) ;
       } else {
     if(par1*par3*geomStepLength < 1.) {
       tlength = (1.-G4Exp(G4Log(1.-par1*par3*geomStepLength)/par3))/par1 ;
     } else {
       tlength = currentRange;
     }
       }
       if(tlength < geomStepLength)   { tlength = geomStepLength; }
       else if(tlength > tPathLength) { tlength = tPathLength; }
     }  
     tPathLength = tlength; 
   }
   //G4cout << "Urban96::ComputeTrueLength: tPathLength= " << tPathLength 
   //     << " step= " << geomStepLength << G4endl;
 
   return tPathLength;
 }

void G4UrbanMscModel::Initialise	(	const G4ParticleDefinition *	p,
		const G4DataVector &
	)

virtual

Implements G4VEmModel.

Definition at line 171 of file G4UrbanMscModel.cc.

References G4VMscModel::GetParticleChangeForMSC(), and G4VMscModel::skin.

 {
   skindepth = skin*stepmin;
   //  trackID = -1;
 
   // set values of some data members
   SetParticle(p);
   /*
   if(p->GetPDGMass() > MeV) {
     G4cout << "### WARNING: G4UrbanMscModel model is used for " 
        << p->GetParticleName() << " !!! " << G4endl;
     G4cout << "###          This model should be used only for e+-" 
        << G4endl;
   }
   */
   fParticleChange = GetParticleChangeForMSC(p);
 
   //samplez = true;
   //G4cout << "### G4UrbanMscModel::Initialise done!" << G4endl;
 }

G4ThreeVector & G4UrbanMscModel::SampleScattering	(	const G4ThreeVector &	oldDirection,
		G4double	safety
	)

virtual

Reimplemented from G4VMscModel.

Definition at line 791 of file G4UrbanMscModel.cc.

References G4VMscModel::dtrl, python.hepunit::eV, G4VMscModel::fDisplacement, G4UniformRand, G4VMscModel::GetDEDX(), G4VMscModel::GetEnergy(), G4VMscModel::latDisplasment, G4ParticleChangeForMSC::ProposeMomentumDirection(), CLHEP::Hep3Vector::rotateUz(), CLHEP::Hep3Vector::set(), and python.hepunit::twopi.

 {
   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 
     //G4cout << "Warning: large scattering E(MeV)= " << kineticEnergy 
     //     << " s(mm)= " << tPathLength/mm
     //     << " 1-cosTheta= " << 1.0 - cth << G4endl;
     // do Gaussian central scattering
   //  if(kineticEnergy > 5*GeV && cth < 0.9) {
   /*
   if(cth < 1.0 - 1000*tPathLength/lambda0 && cth < 0.5 &&
      kineticEnergy > 20*MeV) { 
     G4cout << "### G4UrbanMscModel::SampleScattering for "
        << particle->GetParticleName()
        << " E(MeV)= " << kineticEnergy/MeV
        << " Step(mm)= " << tPathLength/mm
        << " in " << CurrentCouple()->GetMaterial()->GetName()
        << " CosTheta= " << cth << G4endl;
   }
   */
   G4double sth  = sqrt((1.0 - cth)*(1.0 + cth));
   G4double phi  = twopi*G4UniformRand();
   G4double dirx = sth*cos(phi);
   G4double diry = sth*sin(phi);
 
   G4ThreeVector newDirection(dirx,diry,cth);
   newDirection.rotateUz(oldDirection);
   fParticleChange->ProposeMomentumDirection(newDirection);
   /*
   G4cout << "G4UrbanMscModel::SampleSecondaries: e(MeV)= " << kineticEnergy
      << " sinTheta= " << sth << " safety(mm)= " << safety
      << " trueStep(mm)= " << tPathLength
      << " geomStep(mm)= " << zPathLength
      << G4endl;
   */
   if (latDisplasment && safety > tlimitminfix2) {
 
     G4double r = SampleDisplacement();
     /*    
     G4cout << "G4UrbanMscModel::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 = std::cos(Phi);
         diry = std::sin(Phi);
 
         fDisplacement.set(r*dirx,r*diry,0.0);
         fDisplacement.rotateUz(oldDirection);
       }
   }
   return fDisplacement;
 }

void G4UrbanMscModel::StartTracking ( G4Track * track )

virtual

Reimplemented from G4VEmModel.

Definition at line 418 of file G4UrbanMscModel.cc.

References G4DynamicParticle::GetDefinition(), and G4Track::GetDynamicParticle().

 {
   SetParticle(track->GetDynamicParticle()->GetDefinition());
   firstStep = true; 
   inside = false;
   insideskin = false;
   tlimit = geombig;
   stepmin = tlimitminfix ;
   tlimitmin = 10.*stepmin ;
 }

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

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation