RkFitMaterial Class Reference

#include <RkFitMaterial.h>

Public Member Functions
	RkFitMaterial ()
	Constructor.
	RkFitMaterial (double z, double a, double i, double rho, double x0)
	RkFitMaterial (const RkFitMaterial &mat)
double	dE (double mass, double path, double p) const
	Calculate energy loss.
double	mcs_angle (double mass, double path, double p) const
	Calculate Multiple Scattering angle.
double	del_E (double mass, double path, double p) const
	Calculate the straggling of energy loss.
double	X0 (void) const
	Extractor.

Detailed Description

Definition at line 6 of file RkFitMaterial.h.

Constructor & Destructor Documentation

RkFitMaterial() [1/3]

RkFitMaterial::RkFitMaterial ( )

inline

Constructor.

Definition at line 14 of file RkFitMaterial.h.

{}

RkFitMaterial() [2/3]

RkFitMaterial::RkFitMaterial	(	double	z,
		double	a,
		double	i,
		double	rho,
		double	x0
	)

Definition at line 18 of file RkFitMaterial.cxx.

  : x0_(x0), z_(z)  // rho is the density, z is the atomic number, a is the weight
                    // i is mean excitation potention, x0 is the radiation length
{
  rza_ = rho * z / a;
  isq_  = i * i * 1e-18;
}

RkFitMaterial() [3/3]

RkFitMaterial::RkFitMaterial

(

const RkFitMaterial &

mat

)

Definition at line 27 of file RkFitMaterial.cxx.

  : rza_(mat.rza_), isq_(mat.isq_),
    x0_(mat.x0_), z_(mat.z_)
{
   
}

Member Function Documentation

dE()

double RkFitMaterial::dE	(	double	mass,
		double	path,
		double	p
	)		const

Calculate energy loss.

Definition at line 35 of file RkFitMaterial.cxx.

{
  if (!(p>0))
    return 0;
 
  //cout<<"this material:x0 "<< x0_ << " Z  " << z_ << endl
  //    <<"  rho*Z/A  "<< rza_ << " I^2 "<< isq_ << endl;
 
  const double Me = 0.000510999;
  double psq = p * p;
  double bsq = psq / (psq + mass * mass);
  double esq = psq / (mass * mass);
 
  double s = Me / mass;
  double w = (4 * Me * esq
          / (1 + 2 * s * sqrt(1 + esq)
         + s * s));
  // Density correction :
  double cc, x0;
  cc = 1+2*log(sqrt(isq_)/(28.8E-09*sqrt(rza_)));
  if (cc < 5.215) 
    x0 = 0.2;
  else
    x0 = 0.326*cc-1.5;
  double x1(3), xa(cc/4.606), aa;
  aa = 4.606*(xa-x0)/((x1-x0)*(x1-x0)*(x1-x0));
  double delta(0);
  double x(log10(sqrt(esq)));
  if (x > x0){    
    delta = 4.606*x-cc;
    if (x < x1) delta=delta+aa*(x1-x)*(x1-x)*(x1-x);
  }
 // Shell correction :  
  float f1, f2, f3, f4, f5, ce;
  f1 = 1/esq;
  f2 = f1*f1;
  f3 = f1*f2;
  f4 = (f1*0.42237+f2*0.0304-f3*0.00038)*1E12;
  f5 = (f1*3.858-f2*0.1668+f3*0.00158)*1E18;
  ce = f4*isq_+f5*isq_*sqrt(isq_);
  return (0.0001535 * rza_ / bsq
      * (log(Me * esq * w / isq_)
         - 2 * bsq-delta-2.0*ce/z_)) * path;
}

Referenced by TRunge::eloss().

del_E()

double RkFitMaterial::del_E	(	double	mass,
		double	path,
		double	p
	)		const

Calculate the straggling of energy loss.

Definition at line 95 of file RkFitMaterial.cxx.

{
  double sigma0_2 = 0.1569*rza_*path;
 
  if (sigma0_2<0) return 0;
 
  double psq = p * p;
  double bsq = psq / (psq + mass * mass);
 
  // Correction for relativistic particles :
  double sigma_2 = sigma0_2*(1-0.5*bsq)/(1-bsq);
 
  if (sigma_2<0) return 0;
 
  // Return sigma in GeV !!
  return sqrt(sigma_2)*0.001;
 
}

mcs_angle()

double RkFitMaterial::mcs_angle	(	double	mass,
		double	path,
		double	p
	)		const

Calculate Multiple Scattering angle.

Definition at line 83 of file RkFitMaterial.cxx.

{
  //cout<<"this material:x0 "<< x0_ << " Z  " << z_ << endl
  //    <<"  rho*Z/A  "<< rza_ << " I^2 "<< isq_ << endl;
  double t = path / x0_;
  double psq = p*p;
  return 0.0136 * sqrt(t * (mass*mass + psq)) / psq
    * (1 + 0.038 * log(t));
}

X0()

double RkFitMaterial::X0 ( void  ) const

inline

Extractor.

Definition at line 28 of file RkFitMaterial.h.

{ return x0_; }

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

• RkFitMaterial.h
• RkFitMaterial.cxx