To allow for the best separation between cosmics and beam related events one needs distinguish between Spill-On and Spill-Off. This can be achieved with a cut on the first event scaler (ECH_01). This scaler counted a 100 kHz clock and allows to determine the time of each event relative to the `begin of extraction' signal of SIS.
The extraction profile varied during the experiment, both the delay between `begin of extraction' and the first extracted particles as well as the duration of the spill. Thus, the Spill-On Gate cut will be run dependent.
The Spill-On gate values were determined run-by-run from the spill time distribution of the recorded events. This distribution shows a constant background due to cosmics triggers and a beam related component. The Spill-On time interval was defined as the time where the trigger rate was more than 10% above the cosmics level.
All Spill-On gate values are stored in a single file with the format
URN begin endwhich reads like
4013 0 2147483647 4014 0 2147483647 ... 1036 0 2147483647 4036 0 2147483647 4037 76500 287500 4038 77500 290500 4039 74500 297500 4040 86500 281500
INDRA Calibration data