Run modes within EOSGX

 

EOSGX contains the full GEANT code used for event simulations. The relationship between the GEANT event loop and the data (TAS) event loop is determined by the choice of a run mode. There are four run modes: NORM, DSIM, FSIM and DATA. A particular run mode is established with the command RUN_MODE (see Section 3.4).

1. NORM - In the NORMal mode, the GEANT event loop is separate from the TAS event loop. The two halves of the EOSGX program exist in parallel, but there is no event processing link between them. The only connection of any kind is through the display software (see event displays). In this mode, the GEANT code runs as a conventional simulation.
2. DSIM - In this mode the GEANT event loop is called from within the TAS event loop before data analysis has started, in order to produce simulated TPC and TOF hits for the analysis. The TPC hits are written into the TAS HITS table and are input to the tracker for studies of the efficiency of the tracker. The TOF hits will be used to study track matching.
3. FSIM - In this mode, the GEANT event loop is called in order to provide kinematics input to the pad response simulator. The output is either written to a *.BDF file or to the DTS_RAW table directly. There need not be coupling between the TAS and GEANT event loops. However, this mode is unique in that it requires a special initialization of the TPC geometry appropriate for the pad response simulator.
4. DATA - In this mode, the kinematics input to the GEANT event loop is the TRACKS table of the TPC and MUSIC detectors. A TAS event is recast as a GEANT event for the purpose of diagnostic track matching between the TPC, MUSIC and TOF detectors. In this mode the GEANT event loop is called from within the TAS event loop after data analysis has filled the tables.

Some of the run modes require that certain TAS modules be enabled and others disabled for the run modes to work properly. The enabling and disabling of these modules is done automatically, and a list of these modules and others is given in Section 4.