JMARKOV::JRayleighScattering Class Reference

Implementation of the JScatteringModel interface with Rayleigh scattering. More...

#include <JScatteringModel.hh>

Inheritance diagram for JMARKOV::JRayleighScattering:

Public Member Functions
	JRayleighScattering (double _lambda_scat, double _a)
	Constructor. More...
double	getScatteringProbability (double ct)
	Return the probability density as a function of cos(theta) More...
JVersor3D	generateDirection ()
	Return a randomly generated direction according to the scattering probability distribution. More...
virtual double	getScatteringLength ()

Protected Attributes
double	a
double	lambda_scat

Detailed Description

Implementation of the JScatteringModel interface with Rayleigh scattering.

Definition at line 473 of file JScatteringModel.hh.

Constructor & Destructor Documentation

JRayleighScattering()

JMARKOV::JRayleighScattering::JRayleighScattering ( double  _lambda_scat, double  _a  )

inline

Constructor.

note that one should never set a<0

Definition at line 482 of file JScatteringModel.hh.

                                                          {
      lambda_scat  = _lambda_scat ;
      a = _a ;
      if( fabs(a)<0 ) {
        cerr << "Fatal error in initialization of JRayleighScattering: a<0 !" << endl ;
        exit(1) ;
      }
    }

Member Function Documentation

getScatteringProbability()

double JMARKOV::JRayleighScattering::getScatteringProbability ( double  ct )

inlinevirtual

Return the probability density as a function of cos(theta)

dP / dOmega = dP / dcosTheta dPhi

to scatter in a given direction. Theta=0 is forward scattering.

Implements JMARKOV::JScatteringModel.

Definition at line 491 of file JScatteringModel.hh.

                                                 {
      //double ct = cos(dir.getTheta()) ;
      return  (1+a*ct*ct)/(4.0*M_PI*(1+a/3.0)) ;
    }

generateDirection()

JVersor3D JMARKOV::JRayleighScattering::generateDirection ( )

inlinevirtual

Return a randomly generated direction according to the scattering probability distribution.

This uses gRandom.

Implements JMARKOV::JScatteringModel.

Definition at line 496 of file JScatteringModel.hh.

                                  {
      double phi = gRandom->Uniform(0,2*M_PI) ;
      double ct ;
      if( a>0 ) {
        double xi  = gRandom->Uniform(0,1) ;
        double d0 = -9/a ;
        double d1 = 27.0*(1-2*xi)*(3+a)/a ;
        double C  = pow( 0.5*(d1 + sqrt(d1*d1-4*d0*d0*d0) ), 1.0/3.0 ) ;
        ct = -1.0/(3.0)*(C+d0/C) ;
      } else {
        ct = gRandom->Uniform(-1,1) ;
      }
      return JDirection3D( JAngle3D( acos(ct),phi) ) ;
    }

getScatteringLength()

virtual double JMARKOV::JScatteringModel::getScatteringLength ( )

inlinevirtualinherited

Reimplemented in JMARKOV::JCombinedScattering.

Definition at line 73 of file JScatteringModel.hh.

{ return lambda_scat ; }

Member Data Documentation

a

double JMARKOV::JRayleighScattering::a

protected

Definition at line 513 of file JScatteringModel.hh.

lambda_scat

double JMARKOV::JScatteringModel::lambda_scat

protectedinherited

Definition at line 77 of file JScatteringModel.hh.

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

• JScatteringModel.hh