Proto-1 program

Europe/Rome

Introduction:

I have presented at the last CM (June 9) the necessity to update the Prototype program, which was funded by INFN for 2020-2021.

The approved plan saw the integration of 10 PDUs in the Prototype TPC in Q4 2020 and the Proto-1 run at CERN in 2021. 

This plan was revised in November review and shifted of 1 year (TPC ready in July 2021, integration and commissioning in Q4 2021 - Q1 2022). 

My proposal at the CM was to carry out mechanical and cryogenic tests of the TPC in September, then integrate PE and readout and finally perform the commissioning run within Q1 2022. This is what I have included in the TDR and high level milestones table.

After April 2022, we could either continue the run at CERN (if Cryolab space still available) or stop it and possibly decide to bring the prototype and cryogenic system at LNGS (if space/infrastructure available). This is unknown at the moment.

Considering the present unavailability of PDUs and TPC I consider urgent to review the above program and - if confirmed - detail the plan of activities, which needs to be described in the INFN TDR. 

This is also needed in order to secure funds for a possible integration and run (at CERN) in Q4 2021 - Q1 2022.

 

Summary of discussion:

  • Livio: Availability of Cryolab at CERN not a problem because lab space refurbished for DarkSide. Should have a meeting with TE division to inform them of our plans, when these are known (no intermediate plans).
    • Giuliana: do you see possible problems in extending the program after April 2022?
    • Livio: No. Information to TE division just a matter of courtesy.
  • Hanguo: mechanical tests of mockup absolutely needed. Cryogenic tests already satisfactory, will continue next week. Then 1 month break. Activity will resume in September. Decisions on TPC design needed by that time in order to assemble TPC mechanics and test them in cryogenics.
    • Marco: how do you plan to monitor the results of the tests if no readout?
      • Hanguo: no photoelectronics needed for the tests, just camera to monitor mechanics and gas pocket formation. Coatings also not needed.
    • Giuliana: do you need to test HV and field cage, field uniformity?
      • Hanguo: in a second step, test coatings and HV connections. No need to study field uniformity. Rely on Maxwell equations.
    • Eugenio: do you need to test optical planes installation?
      • Hanguo: mechanical mockups sufficient for the tests, to be done after January.
    • Giuliana: are there any tests for which you need SiPMs?
      • Hanguo: No, but for purity for which S2 signals are needed. Current cryo system has no purification loop.
    • Giuliana: do you plan to test the purification loop?
      • Hanguo: no planning to install such a loop at CERN at the moment. Can be planned if collaboration decides so.
  • Eugenio: 1 PDU+ and 1 PDUslim available end September; mechanical mockups for optical planes could be ready after end November (not needed before January according to Hanguo). In order to assemble 10 PDUs 1 month of work.
    • Giuliana: when will SiPMs for 10 PDUs be available? Assuming  only after NOA production starts.
      • Jocelyn: 75 unprocessed wafers could be used to this purpose even before NOA production
      • Eugenio: don't see what could be learned from the operation of so many PDUs in Proto-1
        • Peter: nobody wants to test them in Proto-1, which is only a mechanical test. Will these PDUs be tested in the Naples facility?
          • Giuliana: all produced PDUs will be tested at Naples 
          • Hanguo: if 10 PDUs available for Proto-1 I will test it
          • Eugenio: PDU tests at Naples facility.
    • Eugenio: Mechanical mockups to be installed in Proto-1 in January for mechanical interference, robusteness, etc. No further test needed in Proto-1. If requested to equip Proto-1 with 10 PDUs with final backside, soldering procedures, materials, connectors, we will need further activities wrt currently planned in PE and PDA groups.
      • Giuliana: summarizing, for PE no need to have a run of the fully equipped Proto-1 TPC and no plan in such direction.
  • Marco: DAQ development activity on the Naples facility. Proto-0 with 2 PDUs will allow for DAQ tests on S2. No further tests needed in Proto-1 if no additional channels available. In general, Proto-1 scale useful (not only for DAQ) but it is a complex operation that needs to be planned well in advance.
    • Marco: Will Proto-0 be running with 2 PDUs?
      • Giuliana: it will be running as soon as we have 2 or at least 1 PDU available.
      • Marco: then Proto-1 with 2 PDUs does not add anything to Proto-0
  • Davide: with this configuration of Proto-1 on surface we do not need a run. Proto-0 sufficient.
  • Sandro: on Proto-1 we have been through long distance plans for too long; time has come to proceed step by step. Let's proceed to mechanical tests as planned by Hanguo and then update. We cannot make plans for 2022 in a solid way. We should make sure that Hanguo's plans for 2021 are implemented and we should hold proto meetings to keep track of results from prototyping and eventually be ready to an integration if the conditions are there. Too many uncertainties as of today to make longer term plans.
  • Isabelle: in the context of building the experiment it is critical not to have an intermediate step as Proto-1. Several points raised during Proto review and requiring integration tests with 10 PDUs. These tests should not be dropped. Risky to go directly to DS20k construction.
  • Giuliana: agree with Isabelle. Several steps in the integration that should be tested at an intermediate scale. R&D at a very preliminary level. Crazy to go full scale without testing of purity, fields, electronics, S1-S2 reconstruction, capability to produce high LY. So I don't agree with the outcome of this meeting: collaboration should have been and ought to be ready to plan its activities for 2022, but according to what we heard from L1s there is no capability to plan activities on Proto-1 for 2022 (beyond the mechanical tests). Small scale integration tests will be done in Proto-0 as soon as the urgent tests of the SiPMs that have been recently requested will be concluded. Report at the TB to follow.

 

 

There are minutes attached to this event. Show them.
    • 16:00 17:00
      Discussion on Proto-1 1h
      Speaker: Giuliana Fiorillo (NA)