[Olympus] Trigger rates and dead time

[Alexander Winnebeck]

Dear colleagues,

today we had a chance to take a few runs with 2 GeV electrons and we tested different configurations for understanding trigger rates. The results can be found in the elog http://olympus.desy.de/elog/olympus-trigger/9
We used the kinematic ep trigger, where I used the updated Monte Carlo to generate the coincidence patterns for the different field settings and cuts.
The target flow was set to 0.3 sccm, which is roughly our design flow. 
The toroid turned out to improve the situation enormously. It reduced the trigger rate by a factor of 15, when ramping from 0 to 50% field. Going to full field just reduces the rate further by 20%. The dead time of the DAQ was in the order of 10-15% (50% field and 50 mA).

I guess, next week we will try to do some more test, but these numbers already give some orientation for the field settings and trigger configuration.

Cheers,

Alexander


--
Dr. Alexander Winnebeck
winnebeck at mit.edu

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