[Halld-cal] DRAFT: daq conditions for pi0 calibration runs.

[Elton Smith]

Hi all,

We have promised to provide Alexandre with guidelines for data taking 
for pi0 calibration as input to the commissioning plan (see 
https://halldweb.jlab.org/wiki/index.php/Fall_2015_Commissioning_Plan). 
The present draft plan allocates about 1.5 shifts to this activity. 
However, there are several shifts dedicated to "trigger runs", which 
might be able to accumulate additional data. Here is a draft of run 
conditions for comments and feedback.

Ideally, we can take data which can be used by both the BCAL and FCAL 
for pi0 calibrations.

The main difference in the configuration for BCAL this fall is due to 
the (NSB,NSA). Spring: (5,55), Fall-now (0,26). This will  have the 
immediate effect of lowering the measured pi0 peak.
The FCAL configuration has been changed from (NSB,NSA). Spring (3,20), 
Fall-now (0,15). This will also reduced the measured pi0 peak.

Run conditions: Default settings for trigger settings with solenoid off 
and current beam conditions. Highest beam current but safely away from 
pileup.
Nominal Beam current: 100 nA
Nominal Radiator: 1.12·10-4 R.L.
All detectors on, except for FDC.
Inner FCAL rings removed from trigger sum based on trigger studies.
Nominal trigger (same as spring configuration): FCAL_BCAL trigger .or. 
FCAL only .or. BCAL only (see below)
    Thresholds for the BCAL should be the same as for the spring run.  
FADC250_TRIG_THR = 110 = (110-100)*0.041 MeV/count = 0.4 MeV per cell 
threshold
    Thresholds for the FCAL should be the same as for the spring run. 
FADC250_TRIG_THR = 165 = (165-100)*0.27 MeV/count = 18 MeV per cell 
threshold
Data mode: 7 (75%) and mode 8 (25%) of runs.

-----------------------------------------------------------
Conversion factors used:

FCAL conversions for spring run 0.27 MeV/int count. Assume trigger and 
DAQ conversions about the same
BCAL conversions for spring run 0.029 MeV/int count. Assume trigger = 
0.029/0.7 = 0.041 MeV/int count because of different integration windows

Trigger equation is:
1. 10 FCAL(counts) + 3 BCAL(counts) > 18000 counts  -> Fcal(MeV) + 2 
Bcal (MeV) > 486 MeV
2. FCAL(counts) > 1800 counts -> Fcal(MeV) > 486 MeV
3. BCAL(counts) > 6000 counts -> Bcal(MeV) > 246 MeV






-------- Forwarded Message --------
Subject: 	pi0 distribution without FDC on
Date: 	Fri, 11 Dec 2015 10:54:08 -0500
From: 	wmcginle at andrew.cmu.edu
To: 	elton at jlab.org, dalton at jlab.org



Hello Elton and Mark,

I ran my usually pi0 calibration plugin over field off beam data from last
Spring. I attached a plot of the pi0 distribution with the FDC turned on
and the FDC turned off, and we do a slightly better job with the FDC
turned on, but we can clearly still use FDC off data to do a calibration
if we get enough beam.

In order to plot the pi0 distribution with the FDC turned off I used the
translation table command line argument to parse through all the detector
systems except the FDC_WIRES and FDC_CATHODES. I ran the monitoring_hists
plugin over the data along with my pi0 calibration plugin to check that
there was no data in the FDC, and there wasn't. I hope that this is what
you were expecting me to do, but let me know if it isn't.

Will



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