BOSS_7.0.2: RkFitMaterial Class Reference

List of all members.


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.
Private Attributes
double	rza_
double	isq_
double	x0_
double	z_

Detailed Description

Constructor & Destructor Documentation

RkFitMaterial::RkFitMaterial ( ) [inline]

Constructor.

Definition at line 14 of file RkFitMaterial.h.

00014 {}

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

Definition at line 18 of file RkFitMaterial.cxx.

References isq_, and rza_.

00020   : x0_(x0), z_(z)  // rho is the density, z is the atomic number, a is the weight
00021                     // i is mean excitation potention, x0 is the radiation length
00022 {
00023   rza_ = rho * z / a;
00024   isq_  = i * i * 1e-18;
00025 }

RkFitMaterial::RkFitMaterial ( const RkFitMaterial & mat )

Definition at line 27 of file RkFitMaterial.cxx.

00028   : rza_(mat.rza_), isq_(mat.isq_),
00029     x0_(mat.x0_), z_(mat.z_)
00030 {
00031    
00032 }

Member Function Documentation

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

Calculate energy loss.

Definition at line 35 of file RkFitMaterial.cxx.

References f1, f2, isq_, rza_, s, w, x, and z_.

Referenced by TRunge::eloss().

00037 {
00038   if (!(p>0))
00039     return 0;
00040  
00041   //cout<<"this material:x0 "<< x0_ << " Z  " << z_ << endl
00042   //    <<"  rho*Z/A  "<< rza_ << " I^2 "<< isq_ << endl;
00043 
00044   const double Me = 0.000510999;
00045   double psq = p * p;
00046   double bsq = psq / (psq + mass * mass);
00047   double esq = psq / (mass * mass);
00048 
00049   double s = Me / mass;
00050   double w = (4 * Me * esq
00051               / (1 + 2 * s * sqrt(1 + esq)
00052                  + s * s));
00053   // Density correction :
00054   double cc, x0;
00055   cc = 1+2*log(sqrt(isq_)/(28.8E-09*sqrt(rza_)));
00056   if (cc < 5.215) 
00057     x0 = 0.2;
00058   else
00059     x0 = 0.326*cc-1.5;
00060   double x1(3), xa(cc/4.606), aa;
00061   aa = 4.606*(xa-x0)/((x1-x0)*(x1-x0)*(x1-x0));
00062   double delta(0);
00063   double x(log10(sqrt(esq)));
00064   if (x > x0){    
00065     delta = 4.606*x-cc;
00066     if (x < x1) delta=delta+aa*(x1-x)*(x1-x)*(x1-x);
00067   }
00068  // Shell correction :  
00069   float f1, f2, f3, f4, f5, ce;
00070   f1 = 1/esq;
00071   f2 = f1*f1;
00072   f3 = f1*f2;
00073   f4 = (f1*0.42237+f2*0.0304-f3*0.00038)*1E12;
00074   f5 = (f1*3.858-f2*0.1668+f3*0.00158)*1E18;
00075   ce = f4*isq_+f5*isq_*sqrt(isq_);
00076   return (0.0001535 * rza_ / bsq
00077           * (log(Me * esq * w / isq_)
00078              - 2 * bsq-delta-2.0*ce/z_)) * path;
00079 }

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.

References rza_.

00097 {
00098   double sigma0_2 = 0.1569*rza_*path;
00099 
00100   if (sigma0_2<0) return 0;
00101 
00102   double psq = p * p;
00103   double bsq = psq / (psq + mass * mass);
00104 
00105   // Correction for relativistic particles :
00106   double sigma_2 = sigma0_2*(1-0.5*bsq)/(1-bsq);
00107 
00108   if (sigma_2<0) return 0;
00109 
00110   // Return sigma in GeV !!
00111   return sqrt(sigma_2)*0.001;
00112 
00113 }

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

Calculate Multiple Scattering angle.

Definition at line 83 of file RkFitMaterial.cxx.

References t(), and x0_.

00085 {
00086   //cout<<"this material:x0 "<< x0_ << " Z  " << z_ << endl
00087   //    <<"  rho*Z/A  "<< rza_ << " I^2 "<< isq_ << endl;
00088   double t = path / x0_;
00089   double psq = p*p;
00090   return 0.0136 * sqrt(t * (mass*mass + psq)) / psq
00091     * (1 + 0.038 * log(t));
00092 }

double RkFitMaterial::X0 ( void ) const [inline]

Extractor.

Definition at line 28 of file RkFitMaterial.h.

References x0_.

00028 { return x0_; }

Member Data Documentation

double RkFitMaterial::isq_ [private]

Definition at line 8 of file RkFitMaterial.h.

Referenced by dE(), and RkFitMaterial().

double RkFitMaterial::rza_ [private]

Definition at line 7 of file RkFitMaterial.h.

Referenced by dE(), del_E(), and RkFitMaterial().

RkFitMaterial Class Reference

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation