[Clas12_calcom] [EXTERNAL] Re: new timelines for RGB available - ECAL check - feedback needed

[L Smith]

Hi Silvia,

The timing plots are not from ECAL, since ECAL doesn’t have 120ps resolution.  Some mistake made years ago when that code was put together.

I don’t plan on adjustments but if CALCOM insists it will still take roughly the same time as the test cooking takes to implement, and the 8.5.0/8.7.0 comparison with a fixed calibration can still be done.

Cole   


> On Apr 13, 2023, at 11:53 AM, silvia at jlab.org wrote:
> 
> Thanks, Cole.
> I'd just like not to do too many cookings and spend too much time looking
> at the data if there may be still other adjustments to come on
> calibrations or other CCDB constants.
> If you and CalCom think this is the best that can be done with ECAL, from
> both the gain calibration and the SF parametrization, for electrons and
> photons, we can launch the test cookings.
> Another question: I noticed that while the timing for pi- is consistent
> with the previous cooking/calibrations, the timing for pi+ is now out of
> specs for most runs. Is this something that we should be concerned of or
> not?
> Thanks!
> Best regards,
> Silvia
> 
> 
>> Silvia,
>> 
>> In my view it is more important to look at 8.5.0 vs 8.7.0 with the current
>> calibration. There is already a SF parameterization in place for the first
>> and second half of RGB.  In any case I don’t believe the PMT gains are
>> stable below the 2% level, due to CAEN HV shifts and luminosity dependence
>> (beam current ramping up and down or off for long periods), in addition to
>> the overall slow gain drifts with time.  With this calibration the drift
>> was reduced from 3% to 2%.
>> 
>> Cole
>> 
>>> On Apr 13, 2023, at 9:41 AM, silvia--- via Clas12_calcom
>>> <clas12_calcom at jlab.org> wrote:
>>> 
>>> Dear all,
>>> new timelines for RGB S19 have been produced after the recent changes to
>>> CCDB for ECAL.
>>> They can be found at this link:
>>> https://clas12mon.jlab.org/rgb/pass0/v28.51/tlsummary/
>>> 
>>> I have made a comparison, restricted to ECAL, with the timelines done
>>> with
>>> the February cooking, please find my slides at the link:
>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__box.in2p3.fr_index.php_s_ENtSbFexnzxfxS8&d=DwIFaQ&c=CJqEzB1piLOyyvZjb8YUQw&r=LNUyx07OPlPP7unJr9bKdw&m=8mgJGEUEQzZ4W9FyipfDVE6UURt0xzTx9OghWPgCsecPkUKICtQu5_hk0Nl2THTu&s=d8Mx6e5HUplxhLqEiIebachl1KrOyw3xxWtGXNW_eFM&e=
>>> 
>>> There is an overall loss of electrons/trigger or roughly 2%, with the
>>> new
>>> reconstruction and CCDB.
>>> 
>>> I need feedback from Cole and CalCom in order to decide how to proceed.
>>> 
>>> Should we cook our 6 test runs to verify the performances? Or are
>>> further
>>> changes expected to happen to ECAL calibration constants or SF
>>> parametrizations (for both electrons and photons)?
>>> 
>>> In our RGB meeting of last week various possible tests were mentioned:
>>> - cook the 6 runs with the same CCDB timestamp (the old one or the new
>>> one, or both?) and the two versions of CJ (8.5.0 and 8.7.0)
>>> - cook the 6 runs with the same CJ and different CCDB timestamp.
>>> 
>>> What should we do?
>>> 
>>> Thanks a lot for your feedback.
>>> Best regards,
>>> Silvia
>>> 
>>> 
>>> _______________________________________________
>>> Clas12_calcom mailing list
>>> Clas12_calcom at jlab.org
>>> https://mailman.jlab.org/mailman/listinfo/clas12_calcom
>> 
>> 
> 
>