[Lowq] Minutes of the eg6 meeting on August 18

[Hovanes Egiyan]

  Minutes of the August 18 meeting


       From Lowqwiki

Present: Andrea, Maurizio B., Aji, Hovanes, Stepan, Stephen

On the phone: Raffaella, Kawtar, Raphael, Sebastian

Notes by Hovanes.



    Contents

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    * 1 Main RTPC construction
      <http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_18_meeting#Main_RTPC_construction>
    * 2 Tests of RTPCs
      <http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_18_meeting#Tests_of_RTPCs>
    * 3 Gas system
      <http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_18_meeting#Gas_system>
    * 4 Readout electronics
      <http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_18_meeting#Readout_electronics>
    * 5 Other issues
      <http://clasweb.jlab.org/rungroups/lowq/wiki/index.php/Minutes_of_the_August_18_meeting#Other_issues>

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    Main RTPC construction

    * Stepan reported that the RTPC construction is going well, and he
      presented his timeline for the completion of the main RTPC.

       1. Mount pad board assembly, secure wires on the upstream plate
          and perform voltage test for all GEMs (Tuesday, Aug. 18)
       2. Mount inner foil assembly and close the detector (Wednesday,
          August 19)
       3. Seal holes and purge detector with nitrogen (Thursday, August 20)
       4. Mount divider boards, connect wires (Friday, August 21)

    * The main TPC is expected to be much less leaky than the prototype
      because it has an O-ring on the endplates. The problem with the
      screw-head slightly sticking out was resolved by Andrea and
      Maurizio. Stepan also ordered new RTV with very low outgasing for
      sealing purposes.


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    Tests of RTPCs

    * Stephen is testing the prototype. The HV has been ON Friday and
      Monday, will start test with helium/DME this week.

    * Currently tests of the prototype are done with ?-s and ?
      particles. We can also try to test the TPC with electron source.

    * Stephen will prepare a test plan for the main RTPC in the clean
      room. We can use the a "home-made" readout system while the new
      one is not ready. It was pointed out that eventually Sergey will
      need a special internet connection in the clean room of EEL
      building to avoid security sweeps. Stepan said that such a
      connection now exists in the PCAL area.

    * We decided that we need to put the whole system together sometime
      around September 10, and start testing the whole system. That
      would include the main RTPC, the new readout integrated with DAQ,
      and the new gas system.

    * Raphael and Ahmed will be at the the lab on September 15 to help
      with the tests.


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    Gas system

    * Hovanes reported that the plate for the gas panel was ready, and
      we can start mounting the components on it. After that we need to
      connect them with the pipes and also wire up the control system.
      All needed parts are at the lab, they just need to be mounted.

    * Maurizio Bertoldi from FSU will be helping us with the
      construction of the gas panel hardware. He will go back to FSU on
      Sunday, August 20. He might be able to come back on Aug 31 to help
      with the tests of the gas system. Also he might be able to be here
      sometime on September 20 to help with installation and commissioning.

    * The time estimates for completion of the construction of the gas
      system is about one week. After that the system need to be
      transported to the EEL building and checked for leaks and
      performance. We will need a TOSP for that and a bottle of nitrogen
      with a low scale pressure regulator (~30psi).

    * Hovanes also would like to have a couple of mylar window
      assemblies to blow up to determine how much pressure they will be
      able to withstand to set the limits in control system of the panel.


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    Readout electronics

    * Raffaella told us about the progress with the readout electronics.
      Saverio talked to Luciano (our contact from the CERN)regarding the
      firmware modifications to handle mlutievent buffer with sparcified
      readout list. This option will most like be possible.

    * We should not have any problems borrowing 3 RCUs and DCSs from
      CERN for the duration of eg6. Genova will probably have the
      hardware next week and ship it to JLab. Then we probably will
      receive it at the end of the August.

    * At this point two SIUs are missing, they need to be purchased from
      a Hungarian company. We will also need additional PCI boards if we
      decide to run with more DAQ computers. We have 3 of them now,

    * Raffaella also informed us that there will always be 200 ?s dead
      time in the readout system because that is how long it takes to
      compile the list of the active channels. This means that if we run
      at 2 kHz event rate condition, we will have 40% deadtime in RTPC.


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    Other issues

    * Aji looked at some of the e1-dvcs dedicated runs to understand the
      IC trigger with the new trigger supervisor.

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