| Geant4 Cross Reference |
1 This is an example illustrating the use of the 1 This is an example illustrating the use of the error propagation utility.
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3 A G4ErrorFreeTrajState is created to simulate 3 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.
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5 The geometry is a simplified typical HEP detec 5 The geometry is a simplified typical HEP detector:
6 An air beamline ( BEAM ) 6 An air beamline ( BEAM )
7 An air central detector ( CDET ) 7 An air central detector ( CDET )
8 A copper calorimeter, divided in four ( ECAL 8 A copper calorimeter, divided in four ( ECAL )
9 An aluminium calorimeter, divided in ten ( H 9 An aluminium calorimeter, divided in ten ( HCAL )
10 An air muon detector ( MUON ) 10 An air muon detector ( MUON )
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12 It is inmersed in a magnetic field along the Z 12 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.
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15 The type of target can be chosen with the envi 15 The type of target can be chosen with the enviromental variable G4ERROR_TARGET:
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17 PLANE_SURFACE : use a G4ErrorPlaneSurfaceTa 17 PLANE_SURFACE : use a G4ErrorPlaneSurfaceTarget perpendicular to X at (2241. mm, 0, 0)
18 CYL_SURFACE : use a G4ErrorCylSurfaceTarget 18 CYL_SURFACE : use a G4ErrorCylSurfaceTarget parallel to Z of radius 2220 mm
19 VOLUME : use a G4ErrorGeomVolumeTarget with 19 VOLUME : use a G4ErrorGeomVolumeTarget with volume name "MUON"
20 TRKLEN : use a G4ErrorTrackLengthTarget with 20 TRKLEN : use a G4ErrorTrackLengthTarget with track length 2230 mm
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23 The user may also choose if the propagation is 23 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:
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25 FORWARDS : propagate in the forward directio 25 FORWARDS : propagate in the forward direction
26 BACKWARDS : propagate in the backward direct 26 BACKWARDS : propagate in the backward direction
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29 There are also two modes of propagation, that 29 There are also two modes of propagation, that can be chosen with the enviromental variable G4ERROR_PROP
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31 UNTIL_TARGET : propagate until target, all s 31 UNTIL_TARGET : propagate until target, all steps in one go
32 STEP_BY_STEP propagate until target, return 32 STEP_BY_STEP propagate until target, returning control to the user at each step
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