Warning, /geant4/examples/extended/errorpropagation/errProp/README is written in an unsupported language. File is not indexed.
0001 This is an example illustrating the use of the error propagation utility.
0002
0003 A G4ErrorFreeTrajState is created to simulate a muon track of 20 GeV along the X axis. Then the track is propagated until the target is reached.
0004
0005 The geometry is a simplified typical HEP detector:
0006 An air beamline ( BEAM )
0007 An air central detector ( CDET )
0008 A copper calorimeter, divided in four ( ECAL )
0009 An aluminium calorimeter, divided in ten ( HCAL )
0010 An air muon detector ( MUON )
0011
0012 It is inmersed in a magnetic field along the Z axis with default value -1 kilogauss. This value can be changed with the command "/exerror/setField.
0013
0014
0015 The type of target can be chosen with the enviromental variable G4ERROR_TARGET:
0016
0017 PLANE_SURFACE : use a G4ErrorPlaneSurfaceTarget perpendicular to X at (2241. mm, 0, 0)
0018 CYL_SURFACE : use a G4ErrorCylSurfaceTarget parallel to Z of radius 2220 mm
0019 VOLUME : use a G4ErrorGeomVolumeTarget with volume name "MUON"
0020 TRKLEN : use a G4ErrorTrackLengthTarget with track length 2230 mm
0021
0022
0023 The user may also choose if the propagation is done forwards (the natural way, loosing energy) or backwards (in opposite direction, gaining energy), with the enviromental variable G4ERROR_MODE:
0024
0025 FORWARDS : propagate in the forward direction
0026 BACKWARDS : propagate in the backward direction
0027
0028
0029 There are also two modes of propagation, that can be chosen with the enviromental variable G4ERROR_PROP
0030
0031 UNTIL_TARGET : propagate until target, all steps in one go
0032 STEP_BY_STEP propagate until target, returning control to the user at each step
0033
