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 // $Id: G4ErrorMagFieldLimitProcess.cc 69766 2013-05-14 14:33:55Z gcosmo $ 00027 // 00028 // ------------------------------------------------------------ 00029 // GEANT 4 class implementation file 00030 // ------------------------------------------------------------ 00031 // 00032 00033 #include "G4ErrorMagFieldLimitProcess.hh" 00034 #include "G4ErrorMessenger.hh" 00035 #include "G4TransportationManager.hh" 00036 #include "G4FieldManager.hh" 00037 #include "G4Field.hh" 00038 #include "G4Track.hh" 00039 00040 #ifdef G4VERBOSE 00041 #include "G4ErrorPropagatorData.hh" 00042 #endif 00043 00044 //------------------------------------------------------------------------ 00045 G4ErrorMagFieldLimitProcess:: 00046 G4ErrorMagFieldLimitProcess(const G4String& processName) 00047 : G4VErrorLimitProcess(processName) 00048 { 00049 theStepLimit = kInfinity; 00050 } 00051 00052 00053 //------------------------------------------------------------------------ 00054 G4ErrorMagFieldLimitProcess::~G4ErrorMagFieldLimitProcess() 00055 { } 00056 00057 00058 //------------------------------------------------------------------------ 00059 G4double G4ErrorMagFieldLimitProcess:: 00060 PostStepGetPhysicalInteractionLength( const G4Track& aTrack, G4double , 00061 G4ForceCondition* condition ) 00062 { 00063 *condition = NotForced; 00064 const G4Field* field = 00065 G4TransportationManager::GetTransportationManager()->GetFieldManager() 00066 ->GetDetectorField(); 00067 00068 theStepLength = kInfinity; 00069 if( field != 0 ) { 00070 G4ThreeVector trkPosi = aTrack.GetPosition(); 00071 G4double pos1[3]; 00072 pos1[0] = trkPosi.x(); pos1[1] = trkPosi.y(); pos1[2] = trkPosi.z(); 00073 00074 G4double h1[3]; 00075 field->GetFieldValue( pos1, h1 ); 00076 00077 G4ThreeVector BVec(h1[0],h1[1],h1[2]); 00078 G4double pmag = aTrack.GetMomentum().mag(); 00079 G4double BPerpMom = BVec.cross( G4ThreeVector(pmag,0.,0.) ).mag() / pmag; 00080 00081 theStepLength = theStepLimit * pmag / BPerpMom; 00082 #ifdef G4VERBOSE 00083 if(G4ErrorPropagatorData::verbose() >= 3 ) { 00084 G4cout << "G4ErrorMagFieldLimitProcess:: stepLength " 00085 << theStepLength << " B " << BPerpMom << " BVec " << BVec 00086 << " pmag " << pmag << G4endl; 00087 } 00088 #endif 00089 } 00090 00091 return theStepLength; 00092 }