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 #include <cmath> 00028 00029 #include "G4LowEXsection.hh" 00030 #include "G4SystemOfUnits.hh" 00031 00032 G4double G4LowEXsection:: 00033 CrossSection(G4double aX) const 00034 { 00035 G4double result = 0; 00036 if(aX<front().first) return 0; 00037 G4LowEXsection::const_iterator i; 00038 G4LowEXsection::const_iterator it=end(); 00039 for(i=begin(); i!=end(); i++) 00040 { 00041 if((*i).first/MeV>aX) break; 00042 it = i; 00043 } 00044 G4double x1 = std::log((*it).first); 00045 G4double x2 = std::log((*(it+1)).first); 00046 G4double y1 = std::log((*it).second); 00047 G4double y2 = std::log((*(it+1)).second); 00048 G4double x = std::log(aX); 00049 G4double y = y1+(x-x1)*(y2-y1)/(x2-x1); 00050 result = std::exp(y); 00051 return result*millibarn; 00052 }
1.4.7