BezrukovBugaevModel Class Reference

Bezrukov-Bugaev model for photonuclear interactions of high energy muons as described in: W.Lohmann, R.Kopp and R.Voss, Energy Loss of Muons in the Energy Range 1-10000 GeV, CERN 85-03. More...

#include <BezrukovBugaevModel.h>

Inheritance diagram for BezrukovBugaevModel:

List of all members.

Public Member Functions
	BezrukovBugaevModel ()
	BezrukovBugaevModel (const Material &material)
	~BezrukovBugaevModel ()
double	dE_dx (double E) const
ValidityRange_t	ValidityRange (void) const
Private Member Functions
double	bnuc (double E) const
double	V_max (double E) const
double	ds_dv (double v, double E) const
double	G (double v, double E) const
double	PhotonuclXSec (double v, double E) const

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Detailed Description

Bezrukov-Bugaev model for photonuclear interactions of high energy muons as described in: W.Lohmann, R.Kopp and R.Voss, Energy Loss of Muons in the Energy Range 1-10000 GeV, CERN 85-03.

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Id

BezrukovBugaevModel.cxx,v 1.2 2004/01/05 16:11:12 costas Exp

MuELoss

Costas Andreopoulos <C.V.Andreopoulos@rl.ac.uk> CCLRC, Rutherford Lab. December 10, 2003 _________________________________________________________________________________________

Definition at line 22 of file BezrukovBugaevModel.h.

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Constructor & Destructor Documentation

BezrukovBugaevModel::BezrukovBugaevModel (   )

Definition at line 26 of file BezrukovBugaevModel.cxx. 00026 : 00027 ProcessModel() 00028 { 00029 00030 } //_________________________________________________________________________________________

BezrukovBugaevModel::BezrukovBugaevModel (  const Material &  material  )

Definition at line 32 of file BezrukovBugaevModel.cxx. 00032 : 00033 ProcessModel(material, Process::eNuclearInteraction) 00034 { 00035 00036 } //_________________________________________________________________________________________

BezrukovBugaevModel::~BezrukovBugaevModel (   )

Definition at line 38 of file BezrukovBugaevModel.cxx. { }

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Member Function Documentation

double BezrukovBugaevModel::bnuc (  double  E  )  const [private]

Definition at line 61 of file BezrukovBugaevModel.cxx. References Material::A(), ds_dv(), Integrator::Instance(), Integrator::Simpson(), and V_max(). Referenced by dE_dx(). { // Calculate the b factor for muon nuclear interaction ( -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 = new double[kNV]; for(int iv = 0; iv < kNV; iv++) vds[iv] = (Vmin+(iv+1)*dV) * ds_dv(Vmin+(iv+1)*dV, E); double integral = integrator->Simpson(vds, kNV, dV); delete [] vds; // 1e-7 a dimensional factor: // v*ds/dv (in microbarns) --> v*ds/dv*10^-30 cm^2, N -> N*10^23 return 1e-7*(MuELoss::Na/fMaterial.A())*integral; }

double BezrukovBugaevModel::dE_dx (  double  E  )  const [virtual]

Implements ProcessModel. Definition at line 53 of file BezrukovBugaevModel.cxx. References bnuc(). { // Calculate the muon -dE/dx due to muon nuclear interaction in MeV / (gr / cm^2 ) // Input : E, muon energy in MeV return bnuc(E) * E; }

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

Definition at line 96 of file BezrukovBugaevModel.cxx. References Material::A(), C, G(), and PhotonuclXSec(). Referenced by bnuc(). { // Calculate the differential cross section ds/dv (in microbarn) for muon nuclear // interaction based on the Bezrukov, Bugaev formula. // Input : E, muon energy in MeV // v, fraction of energy transferred to the photon // assert(E >= 0); assert(v > 0); double sig = PhotonuclXSec(v,E); double g = 3.*G(v,E)/4.; double v2 = v*v; double t = MuELoss::Mm_2 *v2/(1-v); double k = 1. - 2./v + 2./v2; assert(t > 0); double m1_2_t = MuELoss::m1_2 / t; double m2_2_t = MuELoss::m2_2 / t; double mm_2_t = MuELoss::Mm_2 / t; double d = MuELoss::m1_2 / ( t + MuELoss::m1_2 ); double A = MuELoss::a * fMaterial.A() * sig * v / (2 * MuELoss::pi); double B = g * ( k*log(1.+m1_2_t) - k*d - 2.*mm_2_t ); double C = 0.25 * ( k*log(1.+m2_2_t) - 2.*mm_2_t ); double D = 0.5*mm_2_t * ( g*d + 0.25*m2_2_t*log(1.+1./m2_2_t) ); return A*(B+C+D); // microbarns }

double BezrukovBugaevModel::G (  double  v, double  E )  const [private]

Definition at line 128 of file BezrukovBugaevModel.cxx. References Material::A(), PhotonuclXSec(), and pow(). Referenced by ds_dv(). { // Calculate the factor G (dimensionless) appearing in the differential photonuclear // interaction xsec // Input : E, muon energy in MeV // v, fraction of energy transferred to the photon // assert(E >= 0); assert(v > 0); double A13 = pow(fMaterial.A(),1/3.); double x = 0.00282 * A13 * PhotonuclXSec(v,E); // factor 0.00282 has units of ub^-1 double x2 = x*x; double x3 = x2*x; return 3. * ( x2/2. - 1. + (1.+x)*exp(-x) ) / x3; }

double BezrukovBugaevModel::PhotonuclXSec (  double  v, double  E )  const [private]

Definition at line 145 of file BezrukovBugaevModel.cxx. Referenced by ds_dv(), and G(). { // Calculate the cross section (in microbarns) for photonuclear interaction // Input : E, muon energy in MeV // v, fraction of energy transferred to the photon // assert(E >= 0); assert(v > 0); double Ep = v*E; // photon energy double loge = log(0.0213*1e-3*Ep); // factor 0.0213 has units of GeV^-1 return 114.3 + 1.647 * loge*loge; }

double BezrukovBugaevModel::V_max (  double  E  )  const [private]

Definition at line 88 of file BezrukovBugaevModel.cxx. References pow(), and Material::Z(). Referenced by bnuc(). { // Calculate the maximum fraction of energy carried to the photon. // Input : E, muon energy in MeV // return ( 1 - (3/4.)*sqrt(MuELoss::e)*(MuELoss::Mm/E)* pow(fMaterial.Z(),1/3.) ); }

ValidityRange_t BezrukovBugaevModel::ValidityRange (  void   )  const [virtual]

Implements ProcessModel. Definition at line 43 of file BezrukovBugaevModel.cxx. References ValidityRange::Emax, ValidityRange::Emin, pow(), ValidityRange_t, 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:

• BezrukovBugaevModel.h
• BezrukovBugaevModel.cxx

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