Spill-On Gate Parameters

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         end
which 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
An interval of (0,2147483647) denotes either a non-physics, and empty or an otherwise bad run.


  1. this dataset has been determined by J. Lukasik
  2. File created in 95% by /u/lukasik/tape/ech/set_thr.C ROOT macro.
  3. 58 runs needed manual correction (by IBR).
  4. Runs 4045-4047 (Au+Au @ 15 MeV/n) have "strange" spills.

Web access

The data is available under spillgate.dat.

GSI local access

The file is accessible from the Linux system under

INDRA Calibration data

Data by J. Lukasik, Web by Walter F.J. Müller
Last modified: Thu Jun 17 18:02:11 CEST 1999