Meeting 2019 06 13

GMn GEM commissioning Meetings: Thursday 9:00am - 10:00pm

Link to all previous meetings: GMn GEM Commissioning Meeting

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Kondo, ... 

GEM testing plans (From Brad's email yesterday)

Hi Kondo, et al,

This is a follow up to a GEM meeting a number of us had this (Wed) afternoon. I've added Seamus and Andrew to the CC list since I gather they will be jumping into the software/analysis this summer (which is great!)

This is an attempt to outline my thoughts about how to

 a) demonstrate to our ourselves that BB + SBS will be ready in time for 2020,
 b) and provide documentation to satisfy the ERR committee.

I know there are 'internal' plans that cover many of the details below, but the Committee would like to make those plans more formal/documented, and show a sufficiently detailed path (with manpower included) to get to the physics goals we need on both the BB electron arm) and SBS (neutron arm).

There are three key recommendations that tie into the GEMs in the recent ERR report:

 [1] Outline a plan and schedule to pursue realistic simulations of high-rate tracking performance in the presence of anticipated      backgrounds, and to take advantage of any opportunities to validate the simulations using real data.

 [4] Provide an evaluation of the expected INFN GEM performance or present a plan for using alternate detectors.

 [5] Provide updated reports and expected performance evaluations for both UVa and INFN GEM detectors based on the most recent test
     results. Present a plan that assures the availability of detectors having suitable performance for the experiment.

I view the time-consuming part of [4] as a subset of [5] from the perspective of the GEM development. I do have a 'backup plan' that I will outline for the response, but I hope it will not be needed.

So, I'd like to focus on [1] and [5] -- both are critical path for the SBS program as a whole (regardless of the GEn impact) anyway.

Based on our phone discussion this afternoon, I would envision something along the following lines. (Perhaps such a plan already exists?)

• • Note: For each step we need to identify who will be in charge of making it happen, and a timeline to track/demonstrate progress.

- Develop/summarize a hardware procurement schedule that identifies what remains to be purchased, who will be placing the order(s), and

 when that will happen. 
 - Is firmware development still on the todo list, or is that all complete and production ready?

- Develop a clear, sufficiently documented plan for demonstrating we have working GEMs.

 1) Define what 'working GEM' means:
    a) ie. track reconstruction efficiency with cosmics of XX%
    b) ie. track reconstruction efficiency with beam (high-rate background) of YY%

 2) Describe how 1a and 1b will be measured/demonstrated:
   - Explicitly define what is meant by 'efficiency' above.
   - Under what hardware/configuration condition(s)?
     - Describe/define the cosmics test stand and DAQ configuration
       - If there are trigger biases, how will they be handled or deconvoluted from the data to extract a clean measure of the
         'physics-relevant efficiency'
       - Is the readout hardware identical to the production configuration?
         - If not, what is missing (SSP firmware, crates, modules, etc), and what is the plan to get those onsite and tested?
     - If we will simulate high rate on the cosmics stand, how? (Fe55 source)?
   - What software will be used to analyze the data?
     - Is it the production software that we will use in the Hall?
       - If not, what is the plan to develop the production software, when will it be ready?

 3) This item addresses Recommendation [1], and connects with bullet 1b in the above list. The ERR committee knows that UVa chambers are
    planned to be used in the upcoming PREx run in Hall A.  They are hoping that we can 'develop a plan' in conjunction with the PREx
    group to validate the simulated track reconstruction predictions for SBS against real data.
    * This requires more discussion because details matter here, but it could be as simple as taking a short run (ie. 5--10 min) with
      a larger than normal beam current * target luminosity to push background rates up in the GEMs as high as we safely/feasibly       can.
      - Verify that the track reconstruction software (to be used for BB and SBS) can handle the 'real' data.
      - Verify that the (independently derived) VDC tracks and GEM tracks from the SBS software are collinear with good efficiency.
    - Or something along these lines...

Update on INFN GEM commissioning (Leo, Evaristo)

https://hallaweb.jlab.org/wiki/images/a/a3/1906_infn_gem_status.pdf

Update on UVa GEM commissioning (Kondo)

• 20190617_GMnGEMcommissioning.pdf‎