- Author
- haseg.nosp@m.awa@.nosp@m.azusa.nosp@m..shi.nosp@m.nshu-.nosp@m.u.ac.nosp@m..jp
Class methods and properties
The method TGCSensitiveDetector::ProcessHits is executed by the G4 kernel each time a charged particle (or a geantino) crosses one of the TGC Gas volumes.
Navigating with the touchableHistory method GetHistoryDepth() through the hierarchy of the volumes crossed by the particles, the TGCSensitiveDetector determinates the correct set of geometry parameters to be folded in the Simulation Identifier associated to each hit. The TGC SimIDs are 32-bit unsigned integers, built using the MuonSimEvent/TgcHitIdHelper class which inherits from the MuonHitIdHelper base class.
We describe in the following, how each field of the identifier is retrieved.
1) stationName and stationPhi: when a volume is found in the hierarchy, whose name contains the substring "station", the stationName is extracted from the volume's name; stationPhi is calculated starting from the volume copy number assigned by MuonGeoModel. Separate cases when the station are "F" or "E" type.
2) stationEta: when a volume is found in the hierarchy, whose name contains the substring "tgccomponent", stationEta is calculated starting from the volume copy number assigned by MuonGeoModel. Possibility to calculate the stationPhi at this level, from the copy number assigned by MuonGeoModel (if the copyNo > 1000).
3) gasGap: when a volume is found in the hierarchy, whose name contains the substring "Gas Volume Layer" or "TGCGas", the gasGap is calculated from the volume copy number, according to the positive or negative Z value, in the Atlas global reference system.
@section Some notes:
1) since the volume copy numbers strongly depend on the database layout, the volume name (whether it contains the string "Q02", for instance) is used to retrieve geometry information. In the year 2018 and even some years before there are not any more other database layouts / volumes than MUONQ02 and therefore some logic was removed
2) for each hit, the time of flight (the G4 globalTime), is recorded and associated to the hit.
3) the TGCHit object contains: the SimID, the globalTime, the hit position in the local reference system, the track director cosine in the local reference system and the track identifier.
Definition at line 71 of file TGCSensitiveDetector.h.