[Halld-cpp] CPP Meeting Minutes, March 9, 2022

[Mark Ito]

Folks,

Please find the minutes here 
<https://halldweb.jlab.org/wiki/index.php/%CE%A0_polarizability_Meeting_Mar_9,_2022#Minutes> 
and below.

   -- Mark

      ____________________________________


    Minutes, Π polarizability Meeting, Mar. 9, 2022

Attending: Alex Austregesilo, Mark Dalton, Albert Fabrizi, Sergey 
Furletov, David Hornidge, Mark Ito (chair), Nikhil Kalra, Ilya Larin, 
Rory Miskimen, Andrew Schick, Simon Taylor, Beni Zihlmann

There is a recording of this meeting 
<https://jlab-org.zoomgov.com/rec/share/P1HYtIgWpNW3M3Nr4Ukj3YADfLkTxiHOONTyB2rYc4JNQKQcJymGJGxCErom-3Ob.xlVJquRn55SKlJDk> 
(Passcode: 2ttBdP*.) on the ZoomGov website.


      Action Items


        Check with Sasha on steps for "replay"

  * Ilya, as previously reported, has looked at the random trigger data
    Sascha Somov took at the end of the SRC runs. He sees rates about 5%
    above what was expected from previous tests.
  * Sergey reported that Sascha has been unable to do further tests on
    the TOF trigger due to interference with the on-going CDC cosmic
    tests. Sergey will confirm this and see if there are any pieces of
    the work that can proceed despite the cosmic run.


        Decide on any work to be done on the TAC

Rory reviewed the email exchange 
<https://halldweb.jlab.org/talks/2022/Status%20of%20the%20TAC%20in%20Hall%20D.pdf> 
he had with Sascha on the TAC. We agreed that it might be better to use 
the CCAL as a total absorption counter since that was the last system 
that was used successfully in the Hall, but mechanical interference with 
the muon chambers is an issue. One idea would be to mount the CCAL on 
the stand for the TAC. We did not know if this is anywhere near feasible 
or not.

Rory will ask Tim if he is having a CPP Design meeting tomorrow 
(Thursday). If so we can discuss this idea there.


        Other Action Items

  * Work with Justin to create the appropriate translation tables for
    the scalers (Beni). No progress to report.
  * Check with Chris about sensor voltage for the LV supplies (Beni). No
    progress to report.
  * Update the database with the microscope translation table (Elton).
    No progress reported.


      Previous CPP meeting: Mar 2, 2022

We looked over the minutes 
<https://halldweb.jlab.org/wiki/index.php/%CE%A0_polarizability_Meeting_Mar_2,_2022> 
from last week's meeting.

Mark mentioned that he is in the process of putting together a new 
version set with the changes that Simon has put in for the FWMPCs, 
including the adjustment Richard Jones requested for backward 
compatibility.

Rory characterized Mark I. showing up for only the last few minutes of 
the meeting as a "tactical error." Mark concurred.


      Previous CPP Software meeting

We reviewed the minutes from the meeting on March 3rd 
<https://halldweb.jlab.org/wiki/index.php/%CE%A0_polarizability_Software_Meeting_Mar_3,_2022> 
without significant comment.


      Announcements

Mark I. has a new dog. His name is Charlie. He announced his presence at 
the meeting. (Charlie announced his presence himself, that is.)


      Action Items

We reviewed them earlier, remarks above.


      CPP voltage controls

No report given.


      Plan for diamond simulations

Richard will do the study based on data from the Canadian light source. 
This will provide guidance for Hovanes Egiyan about where good spots on 
the diamond might be.


      Software/Calibration

No report given.


      MWPC Testing

Beni re-capped the cable situation.

 1. Low-voltage cables: all ready to be installed.
 2. High-voltage cables: cables ready to be installed. Break-out box
    still needed. Chris Stanislav is working on that.
 3. Signal cables: only six on hand. The complete set was due a month
    ago. The manufacturer reports that they received the input materials
    two weeks ago. They are being made now and should be delivered by
    the middle to end of this month.

In the mean time, the six cables can be moved from chamber to chamber to 
look at noise levels in the Hall.


      CPP and NPP Experiment Configuration

Mark I. reminded us to fill in relevant configuration information on the 
wiki page 
<https://halldweb.jlab.org/wiki/index.php/CPP_and_NPP_Experiment_Configuration>. 



      CPP-NPP trigger

Discussed earlier in the meeting.


      DAQ and Electronic Setup

Part of discussion on MWPC Testing, above.


      FCAL Readout Re-Configuration

Mark D. reported on an idea, proposed by proponents of PrimEx, to do a 
gain-equization exercise on the FCAL. In preparation for this they 
propose to reduce gains ab initio on all PMTs to reduce the spread in 
gains as well as bring lowest-gain PMTs off from their current settings 
at the maximum voltage. To offset this change they prose halving the 
voltage range covered by the FADCs on all channels from 2 V to 1 V. The 
proposal is to do this during the CPP run since there will not be time 
to go through the exercise during PrimEx (which follows directly after 
CPP).

Mark D. described an alternate plan where the lowest-gain PMTs get 
replaced so that those channels can be run at a voltage less than the 
maximum.

Those at the meeting were not enthusiastic about performing such a large 
change (corresponding the PrimEx-proposed plan) in the middle of the 
already short CPP/NPP running. In particular this would be a new 
configuration for the FCAL energy trigger (which is based on the FADCs) 
when the NPP experiment depends on it critically.
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