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FDC Weekly Meeting

Date: June 25, 2009

Participants: Daniel, Simon, Bill, Beni, Rich, Mark S., Brian, Roger

Next Meeting: July 2, 2009 @ 1:30 p.m.

General Construction Updates

 - There was a problem with the quantity of the fiber-reinforced gusset 
   pieces due to a communication problem with the shop. We only got half 
   of the pieces required. To save on costs and time, we ordered a second
   set made from aluminum that will be done by the middle of July.
 - The parts for the assembly jig on which the detector stack will be
   constructed have been delivered. Mark S. and Brian will assemble the
   jig when they have time and do some test fits.
 - Bill will take on the preparation for a stack assembly document. A
   draft will be prepared before assembly of the full-scale prototype and
   then fleshed out during the process with relevant photographs taken.
 - Cable preparations:
    * The LV cables have arrived and will be tested in the near future.
    * The parts n' pieces for the HV cables are now all in hand and
      construction and testing will begin over the next several weeks.
    * The signal cables and connectors are in hand and Mark and Brian will
      begin construction as they have time.
    * We still need to decide how much of the outer jacket and braid will 
      be stripped off the signal cables.
 - We are having short daily meetings to review the work on the full-scale 
   prototype construction and to ensure that any snags or problems that 
   come up are immediately addressed.
 - Brian and Mark S. will begin making up the composite frames for the
   two gas windows. They should be ready within a couple of weeks.
 - Mark S. will prepare the order for the cables that will be used to
   attach to the cathodes for the external ground. He will also order the
   sealing epoxy that is used to cover the conducting epoxy.

Wire Frame Update

 - Rich did a series of HV tests on each of the wire planes. There was
   a problem on one board of one frame. Upon inspection we found a sizeable
   number of wires that were not soldered to the solder pads. After
   discussion internally and with IUCF, it seems that the likely culprit
   is that due to the non-flatness of the wire frames, the wires were not
   in contact with the board in the location of the solder pads and they
   popped out of the solder. On the frame that we have inspected, there were
   about 30 such problems, all but 1 were with the sense wires. Armen and
   Brian did all of the repairs on the known wires. Rich will recheck all
   connections and the frame will be fully cleaned again. Rich will then
   move to inspect the remaining boards in turn. This problem is a real
   time sink and is taking time away from cathode construction.
 - We need to have a dedicated meeting to design what the schedule for
   work on the Phase 3 wire winding will be. The highest priority for
   work scheduling will be doing work on upgrades of the wire winding
   facility. This includes a better strongback design, the design and
   construction of precision combs, modification to the wire winding
   table, and a list of other items with the system. Stay tuned, more
   to come.
 - We are pushing hard to begin wire frame construction early next year and
   begin wire winding before the end of 2010. Hopefully this can all procede.
   We are now working to complete the simulation studies with Simon to
   determine if we want to offset neighboring wire layers. More to come in
   the upcoming months.
 - The wire frame construction document is located at:
   /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. We will include
   the information on the wire electroplating process shortly.
 - Bill is now designing the jig for the wire electroplating operation
   and it will be ready for submission to the shop at some point in the
   future. We will make a decision shortly if/when we will electroplate
   the wires for the full-scale prototype.
 - Brian received the SEM scans for our wire from the W&M folks. He will
   generate a final QA report with photos and test results for all wires
   in the next several weeks.

Cathode Update

 - Progress updates:
     * Mark S. has completed edge sealing and gas hole inclusion and sealing
       in 3 of the 8 cathode frames. He is working on this as he has time. He
       has come up with a new application system for the sealing epoxy that
       is faster than the hand application.
     * The edge cutting on all cathode boards was completed last week.
     * Brian and Mark S. laid up another panel set using the new taping
       procedures. The joints between neighboring boards look fine, but DSC
       was concerned that there was too much rough board handling and we
       we revisit construction steps with the next cathode board layup that
       should begin tomorrow and be completed on Monday. For now this board
       is stored in the clean room and will be attached to a tranfer ring
     * We have a plan in place to get the completed cathode boards back under
       environmental control. Hopefully this will happen next week.
     * The 2 micron cathode board that had been in the tensioning system for
       a couple of weeks was laminated to its frame. The procedure had only
       moderate success as the procedure used during the vacuum bagging step
       left a sharp annular crease about 2 inches in from the frame I.D..
       The procedure will be modified to eliminate this problem. After the
       frame was attached, the tension transfer ring was cleaned off and sent
       to the shop to be modified like the other ring. The work on the ring
       was completed in a day and the ring returned to us.
     * The cathode panel that was laid up last week as installed into the
       tensioning system with the modified transfer ring. We were quite
       pleased with the redesign. The board will be tensioned next week
       when Eugene returns from travel. At this time, Eugene will transfer
       knowledge to Mark S. and Brian on how to tension the boards.
     * To finish the flatness scans of our 5 micron board, Micah has
       completed a flatness scan of the granite table surface. Data analysis
       is in progress and we hope to be done with the measurements on this
       board early next week so that it can be put under environmental 
 - We now have received the full order of rigid-flex assemblies. The parts
   have been passed onto the fast electronics group to solder on the
   preamp card edge connectors and the addressing resistors. The problem with 
   the locating holes being too small does not seem to be a problem with
   these boards according to Roger. We need to double check this.
 - Bill has been working on the cathode construction document. He has
   circulated a draft for comment. The file is located at
   /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. As new pictures are
   taken, they are being incorporated. As procedures are modified or
   fine tuned, the document is being updated.
 - We are still working to finalize the PR for the 2 micron cathode board
   material. We now have word from a second source that they should be
   able to produce our board material. This was the same company that
   provided our 5 micron board material. We expect a budgetary estimate
   in the next day or two and then will move to finalize our order for the
   full production stock. Stayed tuned for new developments.
 - 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.
 - Bill would like to modify the design of the system for tensioning the
   cathodes to enable a better technique for vacuum bagging. The big issue
   is to get the air bubbles out and the system is upside down relative to
   what he wants it. We will talk more next time on this.

Cooling System Tests

 - Fernando is in the process of writing up the results from his cooling 
   system studies.  Stay tuned for the GlueX note. He indicated that he
   is back to work on this document and it should be done shortly.

Cosmic Ray Test Stand

 - Beni is continuing work to setup the cosmic ray telescope and test
   system in EEL 126. He would like to have it all up and functioning
   and understood before the end of June. Progress is being made connecting
   up all detectors and getting CODA working.
 - 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.
 - Beni has started a bench test plan for the full-scale prototype and
   we discussed his preliminary document briefly. He will circulate it
   for feedback and we will continue to flesh it out. We want to make sure
   that we do some checks of gas leakage with the prototype. We agreed that
   the best procedure would be to use the P5 gas mixture (non-flammable).
 - Bill has designed a system to rotate the prototype from vertical to 
   horizontal. The drawings have been submitted to the machine shop and the
   pieces should be delivered in about 2 weeks.
 - Safety paperwork for the cosmic ray test stand has been turned over to
   Bert for review. Upon approval we will fill the chambers with gas and
   be able to turn on the high voltages

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.