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G4ErrorMagFieldLimitProcess.cc
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26 // $Id: G4ErrorMagFieldLimitProcess.cc 66892 2013-01-17 10:57:59Z gunter $
27 //
28 // ------------------------------------------------------------
29 // GEANT 4 class implementation file
30 // ------------------------------------------------------------
31 //
32 
34 #include "G4ErrorMessenger.hh"
36 #include "G4FieldManager.hh"
37 #include "G4Field.hh"
38 #include "G4Track.hh"
39 
40 #ifdef G4VERBOSE
41 #include "G4ErrorPropagatorData.hh"
42 #endif
43 
44 //------------------------------------------------------------------------
47  : G4VErrorLimitProcess(processName)
48 {
49  theStepLimit = kInfinity;
50 }
51 
52 
53 //------------------------------------------------------------------------
55 { }
56 
57 
58 //------------------------------------------------------------------------
62 {
63  *condition = NotForced;
64  const G4Field* field =
66  ->GetDetectorField();
67 
68  theStepLength = kInfinity;
69  if( field != 0 ) {
70  G4ThreeVector trkPosi = aTrack.GetPosition();
71  G4double pos1[3];
72  pos1[0] = trkPosi.x(); pos1[1] = trkPosi.y(); pos1[2] = trkPosi.z();
73 
74  G4double h1[3];
75  field->GetFieldValue( pos1, h1 );
76 
77  G4ThreeVector BVec(h1[0],h1[1],h1[2]);
78  G4double pmag = aTrack.GetMomentum().mag();
79  G4double BPerpMom = BVec.cross( G4ThreeVector(pmag,0.,0.) ).mag() / pmag;
80 
81  theStepLength = theStepLimit * pmag / BPerpMom;
82 #ifdef G4VERBOSE
83  if(G4ErrorPropagatorData::verbose() >= 3 ) {
84  G4cout << "G4ErrorMagFieldLimitProcess:: stepLength "
85  << theStepLength << " B " << BPerpMom << " BVec " << BVec
86  << " pmag " << pmag << G4endl;
87  }
88 #endif
89  }
90 
91  return theStepLength;
92 }
G4double condition(const G4ErrorSymMatrix &m)
CLHEP::Hep3Vector G4ThreeVector
virtual void GetFieldValue(const double Point[4], double *fieldArr) const =0
double x() const
const G4ThreeVector & GetPosition() const
virtual G4double PostStepGetPhysicalInteractionLength(const G4Track &track, G4double previousStepSize, G4ForceCondition *condition)
double z() const
G4ErrorMagFieldLimitProcess(const G4String &processName="G4ErrorMagFieldLimit")
G4GLOB_DLL std::ostream G4cout
static G4TransportationManager * GetTransportationManager()
G4FieldManager * GetFieldManager() const
G4ThreeVector GetMomentum() const
double y() const
#define G4endl
Definition: G4ios.hh:61
Hep3Vector cross(const Hep3Vector &) const
double G4double
Definition: G4Types.hh:76
const G4Field * GetDetectorField() const
G4ForceCondition
double mag() const