00001 // 00002 // ******************************************************************** 00003 // * License and Disclaimer * 00004 // * * 00005 // * The Geant4 software is copyright of the Copyright Holders of * 00006 // * the Geant4 Collaboration. It is provided under the terms and * 00007 // * conditions of the Geant4 Software License, included in the file * 00008 // * LICENSE and available at http://cern.ch/geant4/license . These * 00009 // * include a list of copyright holders. * 00010 // * * 00011 // * Neither the authors of this software system, nor their employing * 00012 // * institutes,nor the agencies providing financial support for this * 00013 // * work make any representation or warranty, express or implied, * 00014 // * regarding this software system or assume any liability for its * 00015 // * use. Please see the license in the file LICENSE and URL above * 00016 // * for the full disclaimer and the limitation of liability. * 00017 // * * 00018 // * This code implementation is the result of the scientific and * 00019 // * technical work of the GEANT4 collaboration. * 00020 // * By using, copying, modifying or distributing the software (or * 00021 // * any work based on the software) you agree to acknowledge its * 00022 // * use in resulting scientific publications, and indicate your * 00023 // * acceptance of all terms of the Geant4 Software license. * 00024 // ******************************************************************** 00025 // 00026 // 00027 // ------------------------------------------------------------------- 00028 // 00029 // GEANT4 Class file 00030 // 00031 // 00032 // File name: G4VhElectronicStoppingPower 00033 // 00034 // Author: V.Ivanchenko (Vladimir.Ivanchenko@cern.ch) 00035 // 00036 // Creation date: 20 July 2000 00037 // 00038 // Modifications: 00039 // 20/07/2000 V.Ivanchenko First implementation 00040 // 00041 // Class Description: 00042 // 00043 // Low energy hadrons/ions electronic stopping power parametrisation 00044 // 00045 // Class Description: End 00046 // 00047 // ------------------------------------------------------------------- 00048 // 00049 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... 00050 00051 #include "G4VhElectronicStoppingPower.hh" 00052 #include "G4SystemOfUnits.hh" 00053 #include "G4UnitsTable.hh" 00054 00055 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... 00056 00057 G4VhElectronicStoppingPower::G4VhElectronicStoppingPower(): 00058 theHeMassAMU(4.0026) 00059 {;} 00060 00061 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... 00062 00063 G4VhElectronicStoppingPower::~G4VhElectronicStoppingPower() 00064 {;} 00065 00066 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo.... 00067 00068 G4double G4VhElectronicStoppingPower::HeEffChargeSquare( 00069 const G4double z, 00070 const G4double kineticEnergyHe) const 00071 { 00072 // The aproximation of He effective charge from: 00073 // J.F.Ziegler, J.P. Biersack, U. Littmark 00074 // The Stopping and Range of Ions in Matter, 00075 // Vol.1, Pergamon Press, 1985 00076 00077 static G4double c[6] = {0.2865, 0.1266, -0.001429, 00078 0.02402,-0.01135, 0.001475} ; 00079 00080 G4double e = std::log( std::max( 1.0, kineticEnergyHe/(keV*GetHeMassAMU()))) ; 00081 G4double x = c[0] ; 00082 G4double y = 1.0 ; 00083 for (G4int i=1; i<6; i++) { 00084 y *= e ; 00085 x += y * c[i] ; 00086 } 00087 00088 G4double w = 7.6 - e ; 00089 w = 1.0 + (0.007 + 0.00005*z) * std::exp( -w*w ) ; 00090 w = 4.0 * (1.0 - std::exp(-x)) * w * w ; 00091 return w; 00092 }