Gabriele Cosmo
34 lines
1.5 KiB
Plaintext
34 lines
1.5 KiB
Plaintext
This is an example illustrating the use of the error propagation utility.
|
|
|
|
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.
|
|
|
|
The geometry is a simplified typical HEP detector:
|
|
An air beamline ( BEAM )
|
|
An air central detector ( CDET )
|
|
A copper calorimeter, divided in four ( ECAL )
|
|
An aluminium calorimeter, divided in ten ( HCAL )
|
|
An air muon detector ( MUON )
|
|
|
|
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.
|
|
|
|
|
|
The type of target can be chosen with the enviromental variable G4ERROR_TARGET:
|
|
|
|
PLANE_SURFACE : use a G4ErrorPlaneSurfaceTarget perpendicular to X at (2241. mm, 0, 0)
|
|
CYL_SURFACE : use a G4ErrorCylSurfaceTarget parallel to Z of radius 2220 mm
|
|
VOLUME : use a G4ErrorGeomVolumeTarget with volume name "MUON"
|
|
TRKLEN : use a G4ErrorTrackLengthTarget with track length 2230 mm
|
|
|
|
|
|
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:
|
|
|
|
FORWARDS : propagate in the forward direction
|
|
BACKWARDS : propagate in the backward direction
|
|
|
|
|
|
There are also two modes of propagation, that can be chosen with the enviromental variable G4ERROR_PROP
|
|
|
|
UNTIL_TARGET : propagate until target, all steps in one go
|
|
STEP_BY_STEP propagate until target, returning control to the user at each step
|
|
|