PetrukhinShestakovModel Class Reference

#include <PetrukhinShestakovModel.h>

Inheritance diagram for PetrukhinShestakovModel:

List of all members.

Public Member Functions
	PetrukhinShestakovModel ()
	PetrukhinShestakovModel (const Material &material)
	~PetrukhinShestakovModel ()
double	dE_dx (double E) const
ValidityRange_t	ValidityRange (void) const
Private Member Functions
double	bbrem (double E) const
double	V_max (double E) const
double	ds_dv (double v, double E) const
double	fi (double v, double E) const
double	delta (double v, double E) const

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Detailed Description

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Id

PetrukhinShestakovModel.cxx,v 1.2 2004/01/05 16:11:13 costas Exp

Definition at line 24 of file PetrukhinShestakovModel.h.

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Constructor & Destructor Documentation

PetrukhinShestakovModel::PetrukhinShestakovModel

(

)

Definition at line 26 of file PetrukhinShestakovModel.cxx.

00026                                                  :
00027 ProcessModel()
00028 {
00029 
00030 }
//_________________________________________________________________________________________

PetrukhinShestakovModel::PetrukhinShestakovModel

(

const Material &

material

)

Definition at line 32 of file PetrukhinShestakovModel.cxx.

00032                                                                           :
00033 ProcessModel(material, Process::eBremsstrahlung)
00034 {
00035 
00036 }
//_________________________________________________________________________________________

PetrukhinShestakovModel::~PetrukhinShestakovModel

(

)

Definition at line 38 of file PetrukhinShestakovModel.cxx.

{

}

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Member Function Documentation

double PetrukhinShestakovModel::bbrem

(

double

E

)

const [private]

Definition at line 61 of file PetrukhinShestakovModel.cxx.

References Material::A(), ds_dv(), ProcessModel::fMaterial, Integrator::Instance(), MuELoss::Na, Integrator::Simpson(), and V_max().

Referenced by dE_dx().

{
// Calculate the b factor for muon bremsstrahlung ( -dE/dx = b*E ) in cm^2 / gr
// Input  : E, muon energy in MeV

  const int kNV = 600;

  double Vmin = 0;
  double Vmax = V_max(E);
  double dV   = (Vmax - Vmin) / kNV;

  Integrator * integrator = Integrator::Instance();

  double * vds_dv = new double[kNV];
  
  for(int iv = 0; iv < kNV; iv++) 
                      vds_dv[iv] = (Vmin+(iv+1)*dV) * ds_dv( (Vmin+(iv+1)*dV), E);

  double integral = integrator->Simpson(vds_dv, kNV, dV);

  // factor 10 is for dimensions:
  //    10 :   v*ds/dv(integral) in 10^22 cm2 --  N->N*10^(-23) -> b in 0.1 cm2/gr
  return 10*(MuELoss::Na/fMaterial.A())*integral;
}

double PetrukhinShestakovModel::dE_dx

(

double

E

)

const [virtual]

Implements ProcessModel.

Definition at line 53 of file PetrukhinShestakovModel.cxx.

References bbrem().

{
// Calculate the muon -dE/dx due to muon bremsstrahlung in MeV / (gr / cm^2 )
// Input  : E, muon energy in MeV

  return bbrem(E) * E;
}

double PetrukhinShestakovModel::delta	(	double	v,
		double	E
	)			const [private]

Definition at line 134 of file PetrukhinShestakovModel.cxx.

References MuELoss::Mm_2.

Referenced by fi().

{
// Calculate the minimum monentum transfer to the nucleus in MeV
// Input   : v, the fraction of energy transfered to the photon
//           E, muon energy in MeV

 return MuELoss::Mm_2 * v / (2*E*(1-v));
}

double PetrukhinShestakovModel::ds_dv	(	double	v,
		double	E
	)			const [private]

Definition at line 91 of file PetrukhinShestakovModel.cxx.

References MuELoss::a_3, fi(), ProcessModel::fMaterial, MuELoss::Le_2, MuELoss::Me_Mm_2, and Material::Z().

Referenced by bbrem().

{
// Calculate the Bethe-Heitler cross section ds/dv for muon bremsstrahlung in 10^22 cm^2
// Input  : v, the fraction of energy transfered to the photon
//          E, muon energy in MeV
//
  assert( v > 0 );
  assert( E >=0 );

  double a_3     = MuELoss::a_3;
  double z_2     = pow(fMaterial.Z(),2);
  double le_2    = MuELoss::Le_2;
  double me_mm_2 = MuELoss::Me_Mm_2;

  return a_3 * 4*z_2 * le_2 * me_mm_2 * ( ( 4/3. - 4*v/3. + v*v )/v ) * fi(v,E);
}

double PetrukhinShestakovModel::fi	(	double	v,
		double	E
	)			const [private]

Definition at line 108 of file PetrukhinShestakovModel.cxx.

References MuELoss::a, delta(), ProcessModel::fMaterial, MuELoss::Me, MuELoss::Mm_Me, MuELoss::sqrt_e, and Material::Z().

Referenced by ds_dv().

{
// Calculate the fi(d) factor for the bremsstrahlung cross section ds/dv according to the
// Petrukhin/Shestakov formula (dimensionless)
// Input   : v, the fraction of energy transfered to the photon
//           E, muon energy in MeV

  double d = delta(v,E);

  if( fMaterial.Z() < 10 ) {

     double a = (189.*MuELoss::Mm_Me ) * pow(fMaterial.Z(),-1./3.);
     double b = 1 + (189./MuELoss::Me) * pow(fMaterial.Z(),-1./3.) * MuELoss::sqrt_e * d;

     return log(a/b);

  } else if ( fMaterial.Z() > 10 ) {

     double a = (2./3.) * (189.*MuELoss::Mm_Me) * pow(fMaterial.Z(),-2./3.);
     double b = 1 + (189./MuELoss::Me) * pow(fMaterial.Z(),-1./3.) * MuELoss::sqrt_e * d;

     return log(a/b);

  } else return 0;
}

double PetrukhinShestakovModel::V_max

(

double

E

)

const [private]

Definition at line 86 of file PetrukhinShestakovModel.cxx.

References MuELoss::e, ProcessModel::fMaterial, MuELoss::Mm, and Material::Z().

Referenced by bbrem().

{
  return ( 1 - (3/4.)*sqrt(MuELoss::e)*(MuELoss::Mm/E)* pow(fMaterial.Z(),1/3.) );
}

ValidityRange_t PetrukhinShestakovModel::ValidityRange

(

void

)

const [virtual]

Implements ProcessModel.

Definition at line 43 of file PetrukhinShestakovModel.cxx.

References MuELoss::e, ValidityRange::Emax, ValidityRange::Emin, ProcessModel::fMaterial, MuELoss::Mm, and Material::Z().

{
  ValidityRange_t validity_range;

  validity_range.Emin = 0.75*sqrt(MuELoss::e)*(MuELoss::Mm)*pow(fMaterial.Z(), 1./3.);
  validity_range.Emax = 10000000.; // MeV

  return validity_range;
}

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

• PetrukhinShestakovModel.h
• PetrukhinShestakovModel.cxx

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