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FDC Weekly Meeting

Date: April 2, 2009

Participants: Daniel, Bill, Beni, Brian, Mark S., Simon, Roger, Mark I., Eugene, Fernando, Kim

Next Meeting: April 9, 2009 @ 1:30 p.m.

Full-Scale Prototype Updates

 - Cathode Board Orders
    * Cathode boards: The PR is about to be signed. We have asked for a
      few last minutes updates to the drawings. One is to move the artwork
      on the end boards by 0.5 in. Also, remove the copper outer edge of
      the boards (Bill will supply the appropriate radius). We most likely
      will want the boards shipped flat using our transport box. A decision
      will be made shortly along with final packing instructions. The final
      order will have 7 sets of 2 micron Cu boards and 1 set of 5 micron Cu
    * Corrosion issue: Roger is waiting to talk to the sales representative
      at Allflex regarding these issues. Probably will include a second
      deionized water rinse step.
    * Cathode daughter boards: the PR will be ready when that for the cathode
      boards goes out.
    * Eugene has identified the accounts to be charged for these two PRs.
 - Chamber Wire:
    * We are waiting for the W&M SEM folks to finish training their folks
      on the new SEM and then they will finish our wire QA checkout. Brian 
      will prepare a final QA report with photos and test results for all 
      wires when all studies are complete.
 - Soldering Work: Kim will set up a meeting in a couple of weeks between
   the FDC group and Greg's group for the soldering work for the cathodes
   and wire frames. We can talk about our schedules and needs and work out
   manpower details.

Wire Frame Update

 - Status: Two wire frames (P4 and P1) have been wound. A third frame has
   had the wires attached but measurements of tension and wire position
   are pending. The linear transducer should have been sent off for 
   refurbishment, but has been delayed due to IUCF red tape. Once it is
   sent out, it should be back and reinstalled in about 2 weeks. Keith will
   check on the status this week.
 - Folks who have not read Bill's IUCF trip report (GlueX-doc-1229)
   should look it over and provide feedback.  Keith has just gotten back
   from a trip and will be looking it over to try to start filling in some
   missing numbers.
 - Bill has been updating the wire frame construction document based on 
   lessons learned from the prototype frames. He is working to incorporate
   some more relevant photographs. A new version will be posted when his
   work is done.
 - Brian and Mark worked this week to electroplate Cu on the sense wires
   in a diameter close to what we will use in the final detector. This
   work was done with Tom Elliott. Five attempts were made on one of our
   existing full-scale wire frames. Ultimately a set of parameters (times,
   voltages, currents, polarities) were found that seemed to give a
   smooth Cu distribution with a final wire size about 4 times larger.   
   We have not done any tests yet to see if the work is good enough for
   the final detector, and will have to think about it. The photographs
   taken will be built into the procedures document that Brian will be
   preparing.  Bill will design an alignment jig and a system for attaching 
   the electrical leads to the chambers.
 - The bearing for the rotatable platter for the Phase 2 soldering is in
   hand. Bill will complete the design and get the drawings to the shop

Cathode Construction

 - We reviewed the cathode R&D timeline.  The current schedule is being kept 
   on the mdrive at:
     * Location: M:\halld\Individual-Schedules\FDC or for more sophisticated 
       folks, /u/group/halld/Individual-Schedules/FDC
 - Progress updates:
     * The G10 pieces for the cathode frames have arrived. The plan is
       to begin production mode for the full-scale prototype frames so that
       they are ready for the JLab machine shop at the end of this month.
       The end of this month (beginning of May really) is when the horizontal
       mill is available for our use.
     * We made up a second 3 piece cathode panel with a set of our 5 micron 
       Cu boards. The boards looked very nice and we found fairly uniform
       tension in the dimension across the strips. Along the strips, a
       small gradient remained even though we had a cathode with no wrinkles.
       It appears to the lack of symmetry of the boards (one connector on
       side and 8 on the other) that the asymmetry may be unavoidable. Even
       with this though, the tension gradient was only about 50 N/m, so
       it seems reasonable. The tension gradient should be less with the
       2 micron Cu boards as the copper on the 5 micron Cu boards is quite
     * Brian and Mark have made up a 2 micron Cu cathode panel and will
       attach it to the transfer ring this week and perform some tension
       measurements. We will most likely also make up the second 2 micron
       Cu board for tension studies. We need to finalize our tension
       settings and procedures with these boards for the full-scale
     * We discussed some simple modifications to the large G10 tensioning
       ring that would improve the process. We will hold off on these due
       to budget concerns for a bit until the budget issues are resolved.
     * We have 5 prototype rigid flex assemblies (cathode daughter boards)
       and 5 connectors for the preamp daughter boards. Greg Arnold's group 
       solder on the connectors. The boards will be fitted into a local area 
       on the cathode mechanical sandwich prototype to study access and 
       space conflicts to finalize the design.  Hopefully this gets done in
       the next week.
     * Bill has been working on the cathode construction document. He will
       circulate a draft shortly.

Cathode Flatness Measuring System

 - Documentation of the system continues. See the FDC wiki page for details.

Stack Assembly Procedures

 - Bill will work to finalize the stack assembly construction document 
   that has been prepared.  This document should be in place before we get 
   too far in the construction process.
 - Bill has found some plastic threaded rods that could be used to 
   compress the stack.  We will be receiving some samples shortly and
   will carry out some loading tests.

Cooling System Tests

 - Fernando is in the process of writing up the results from his cooling 
   system studies.  Stay tuned for the GlueX note.
 - Bill has done some ANSYS modeling to better study the connector that 
   goes from the daughter board card to the cooling loop.  These will be
   added to Fernando's note.


 - Roger needs to prepare a document for QA/stuffing/cleaning for the
   cathode boards and a similar document for the cathode daughter
   boards and ground boards.

Cosmic Ray Test Stand

 - We will be moving the FDC cosmic ray test stand from the Test Lab back
   to the EEL building. Beni is working on designing the room layout in
   EEL 126. The move of the cosmic ray test stand from the Test Lab does
   not need to happen in April as the planned magnet tests have been
   detailed for the time being. Still, we need to get things over to EEL
   for testing.
 - We still have some mysterious behavior with the small-scale prototype
   response with wiggles in the X vs. Y distributions that need to be
   understood. We decided to have a separate meeting to discuss what work
   we would like to do on the small-scale prototype.
 - We would like to put together a bench test plan for the full-scale 
   prototype within the next couple of weeks. This preliminary test plan 
   will be used to provide information on what test stand fixtures to 
   support the chamber we will require. Bill can then work on the design 
   and get things prepared in the shop.  Also, we would like to layout a 
   design for the electronics before too much longer so that we can reduce 
   time from when the full-scale prototype is constructed to when we get 
   into the test plan.

Work List

 - The FDC short-term work list has been posted on the FDC web site.  
   This is continually being updated and DSC welcomes any feedback or 
   comments from the group.

Minutes prepared by Daniel. Send any comments or corrections along.