[Rgc_analysis] Run integrated fcup charge reading lower than before in recent runs

[pilleux at jlab.org]

Hello Nathan,

I am computing the expected charge as run duration*run current where I
read the time and current from RCDB.
I am computing the charge from the run::scaler bank by using the last
reading in the run (using dst recon files) and normalizing it by the
fraction of the run that was cooked : charge = last run::scaler reading *
number of evio files in the run / number of cooked files. I am pulling the
number of evio files from RCDB.

Here is the code I use to read run::scaler (sorry for the messy code as it
was just for checking it quickly) :
/work/clas12/pilleux/read_run_scaler.cpp
To run it :
> clas12root -l
> read_run_scaler(int run_min, int run_max)
It produces a text file with 3 columns for run number, number of cooked
files, and the last run::scaler reading. Depending on the run number the
path in line 31 needs to be changed with /TBT/ or /HBT/ (depending on how
the file was cooked).

Here is a complete file with the additionnal RCDB info that I am using :
/work/clas12/pilleux/compa_run_scaler_expected_charge.csv

Thank you. Best regards, Noémie.



> Hi Noémie,
>
> Can you explain exactly how you're calculating these numbers for beam
> charge?  Both the blue and orange numbers.  What exactly do those numbers
> represent?  If you can also provide the corresponding software that would
> be great.
>
> -Nathan
>
>
>> On Sep 30, 2022, at 12:17 PM, pilleux at jlab.org wrote:
>>
>> Dear Raffaella, dear Nathan, and dear RGC analysts,
>>
>> As discussed in previous analysis meetings, I wanted to compare how our
>> number of events changes in elastic and dvcs data between the low
>> current
>> and high current configurations.
>>
>> To that extent, I need to normalize the rates we get, ideally with the
>> FCup readings. Using the RUN::scaler bank (which uses different scaler
>> information than the HEL::scaler bank for which Greg showed issues), I
>> noticed some trend that I don't understand. Please find attached a plot
>> that shows that for recent runs, the accumulated charge that is
>> registered
>> (in blue) is lower than before compared to the expected charge (that I
>> compute from current and run time, in orange).
>>
>> Some more information to get a headstart on debugging : All these
>> numbers
>> are DAQ gated so should be independent of beam trips if I understand
>> correctly. They take into account the fraction of files that were
>> cooked
>> compared to the number of files in the whole run. I also crosschecked
>> with
>> Greg's code (thank you!) that we are reading the same values from the
>> banks.
>>
>> Am I missing a change that would explain this drop ? Or can this be due
>> to
>> the calibration of the scaler constants ?
>>
>> Thank you. Best regards, Noémie.<run_scaler_comparison.png>
>
>