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geant4/source/processes/electromagnetic/lowenergy/src/G4VhElectronicStoppingPower.cc
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//
// ********************************************************************
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// -------------------------------------------------------------------
//
// GEANT4 Class file
//
//
// File name: G4VhElectronicStoppingPower
//
// Author: V.Ivanchenko (Vladimir.Ivanchenko@cern.ch)
//
// Creation date: 20 July 2000
//
// Modifications:
// 20/07/2000 V.Ivanchenko First implementation
//
// Class Description:
//
// Low energy hadrons/ions electronic stopping power parametrisation
//
// Class Description: End
//
// -------------------------------------------------------------------
//
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
#include "G4VhElectronicStoppingPower.hh"
#include "G4SystemOfUnits.hh"
#include "G4UnitsTable.hh"
#include "G4Exp.hh"
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
G4VhElectronicStoppingPower::G4VhElectronicStoppingPower():
theHeMassAMU(4.0026)
{;}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
G4VhElectronicStoppingPower::~G4VhElectronicStoppingPower()
{;}
//....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo....
G4double G4VhElectronicStoppingPower::HeEffChargeSquare(
const G4double z,
const G4double kineticEnergyHe) const
{
// The aproximation of He effective charge from:
// J.F.Ziegler, J.P. Biersack, U. Littmark
// The Stopping and Range of Ions in Matter,
// Vol.1, Pergamon Press, 1985
static const G4double c[6] = {0.2865, 0.1266, -0.001429,
0.02402,-0.01135, 0.001475} ;
G4double e = std::log( std::max( 1.0, kineticEnergyHe/(keV*GetHeMassAMU()))) ;
G4double x = c[0] ;
G4double y = 1.0 ;
for (G4int i=1; i<6; i++) {
y *= e ;
x += y * c[i] ;
}
G4double w = 7.6 - e ;
w = 1.0 + (0.007 + 0.00005*z) * G4Exp( -w*w ) ;
w = 4.0 * (1.0 - G4Exp(-x)) * w * w ;
return w;
}