[Halld-level1] [Revised Logentry] Trigger studies for FDC calibration, summary

[somov at jlab.org]

Logentry Text:
--
Together with Lyubomir we were optimizing trigger for the FDC calibration, some data was taken over last night.

FCAL + TOF trigger
--------------------------

FCAL E_total = 1500, E_cell = 65
TOF trigger thr = 400

rate ~40 Hz for 50 nA (beam not stable)

Run 2900
Run 2901
Large fraction of good tracks according to Lyubomir.
Trigger problems: not uniform occupancy for reconstructed tracks, area(s) with large occupancy observed
(this feature is likely due to the TOF algorithm, fadc scalers for TOF don't indicate hot areas)

Check uniformity with FCAL trigger

Run 2901 (E = 1500, 65, rate ~900 Hz for 70 nA, beam not stable)
Uniform distribution of reconstructed tracks, smaller fraction of tracks in the data sample.

FCAL + ST trigger
------------------------
FCAL: E=1500, 66
ST thr = 50
Rate ~80 Hz for 60 nA (beam not stable)

Seems to be a reasonably good trigger for the FDC calibration !

The fraction of events with reconstructed tracks is slightly smaller
than that for the FCAL + TOF trigger, but uniform occupancy of reconstructed 
tracks was observed.

Run 2903

Configuration:  FCAL_ST_m8.conf

Asked to take data during night.

Misc. problems:
--------------------
FCAL: one noisy channel showed up when the beam was on (was blocking the FCAL trigger - masked), Slot 15, Ch 13
beam related (?) - Adesh is going to checked. This channel seemed to be Ok before.

DAQ: periodically disconnected coda components during RC state transitions; had to restart run couple of times
(daq is stable when evth. is connected/configured) 


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