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FDC Weekly Meeting

Date: April 23, 2009

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

Next Meeting: May 7, 2009 @ 1:30 p.m. (Note: No meeting next week)

Full-Scale Prototype Updates

 - Cathode Board Orders
    * Cathode boards: Roger has reviewed the order with the Allflex folks. 
      We are still expecting delivery by the beginning to middle of May. 
      Mark S. will send the transport box up to Allflex by tomorrow. Roger 
      still has to send up a note on packing and shipping instructions.
      This will happen soon. The issue of board corrosions and steps to
      mitigate this further are being considered at the company. They
      will update Roger shortly.
    * Cathode daughter boards: Roger has received quotes and the PR is
      being finalized. Not much longer until this goes out.  Expected turn 
      around time is 2 weeks.
 - Chamber Wire:
    * Brian announced that the SEM studies of our wires should be complete
      very shortly. This includes a check of the ovality of our sense
      wire and the mass spectroscopy reports. Stay tuned.  Brian will 
      prepare a final QA report with photos and test results for all wires 
      when all studies are complete.
 - Soldering Work: 
    * Greg Arnold's group will not be available for our work until maybe the 
      end of May. It looks like we can get manpower if needed through Chris 
      Cuevas' group so that delays on the wire board Phase 2 soldering and 
      the connection of the rigid-flex assemblies to the cathodes is not 
      delayed.  We may need to borrow the wave solder machine from Greg's 
      group. More to come as schedules come into focus.
    * To avoid concerns with melting the epoxy on the cathode boards during
      soldering of the rigid-flex assemblies, we want to do a test to make
      sure that there are no problems. Mark and/or Brian will set this up.
 - We are now sharing the clean tent with Hall B.  The Hall B folks will
   need about 2 to 3 weeks of time to finish their work.
 - Bill received an estimate to make up 22 new cooling system clamps. The
   price is about $100 apiece. This PR has been signed and we expect the
   pieces back within a couple of weeks.
 - We reviewed remaining tasks to complete the design of the FDC design.
   DSC showed a preliminary list (see FDC design task list). This needs 
   to be looked over and fleshed out by folks. DSC reminded folks to give him 
   feedback about this list.
 - Bill will put together the order for the o-ring material for the
   full-scale prototype.

Wire Frame Update

 - Status: The linear transducer has finally been sent off for refurbishment
   It should be back and reinstalled in about 1 week. 
 - As the IUCF work has been delayed, DSC has requested a no-cost extension
   for one month and talked to Sharon Williams. This work will be completed
 - Bill will send Keith some information on which sections of the wire
   winding procedures document needs input from them to filling in holes.
   The start of this procedures document is included in Bill's IUCF trip 
   report (GlueX-doc-1229).
 - Bill has been updating the wire frame construction document based on 
   lessons learned from the prototype frames. The newest version is located 
   at /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. Please read it over 
   and give him feedback.
 - Brian will gather all the bits n' pieces for a write-up on the wire
   electroplating and post his document on the mdrive for feedback.
 - 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. This is not a high-priority job at the moment.
 - The bearing for the rotatable platter for the Phase 2 soldering is in
   hand. Mark will put this jig together in the next couple of weeks.
 - Mark will test fit the wire frame protective cover to be sure it is
   idiot-proof and does the required job.

Cathode Construction

 - We reviewed the cathode R&D timeline.
 - Progress updates:
     * The 8 cathode frame laminates and G10 annuli have been given over
       to the JLab machine shop. It will be decided in the next day or
       two whether the work is done in house or on the outside. The job
       will then take two weeks to complete.
     * Other JLab machine shop work: The aluminum clamp ring for the 
       tensioning facility will have its I.D. increased to give better
       access; One of the G10 tensioning rings will have its I.D. increased
       and will get a skim cut to remove old glue and Kapton; the thin G10
       rings that make up the remainder of the cathode frame laminates will
       have all the through-holes and gas holes added. These pieces have
       been handed over to the machine shop.
     * To deal with issues of epoxy seepage through our Kapton tape, we have
       done a test of a modified procedure where we first put removable tape
       on the copper side of the boards. After applying the Kapton tape to
       the back of the boards and allowing for it to cure, the tape on the
       front side is removed. This worked very well and we will do a few more
       test with some dummy boards before laying up the last 2 micron Cu
       board set. For this work, we cannot float the boards in alcohol as it
       desolves the glue on the removable tape. Water has been shown to work
       as a reasonable alternative. Trying to lay the cathode panels up 
       without water or alcohol does not work as the ends of the boards
       tend to curl up.
     * Some progress on the mechanical prototype. The power connectors
       have been soldered to the rigid-flex assemblies and the preamp card
       connectors have been added to the wire frame. Next week this system
       will be put together for design checks. This will include the cooling
       lines for the preamp cards.
     * 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.
 - In order to make decisions on the tension settings for the cathode planes,
   we want to understand the surface flatness. We will want to scan our
   5 micron Cu cathode and then to scan our 2 micron Cu cathode once we have
   a frame to mount it to.  This is important input on the minimum tension
   values.  The 5 micron Cu board is ready for scanning and the 2 micron Cu
   board will have to wait until we have a frame to mount it to.

Stack Assembly Procedures

 - Brian agreed to start a draft of the stack assembly document. This 
   document should be in place before we get too far in the construction 
 - Bill has some design work to do to finalize the plans for stack
   compression. He is starting to think about this more.

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 has come up with plans for the room layout in
   EEL 126. We will be working to remove the big storage shelf system to
   clear up space and try to get this out of the room in the next 2 to 3 
 - 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 and/or Brian will start to think about designing a system to rotate
   the prototype from vertical to horizontal.
 - For the full-scale prototype tests, we will have roughly 30 preamp
   boards stuffed (to be shared among everyone), 3 125 MHz FADCs, and
   "plenty" of TDCs. We need to flesh out a plan for who gets what and
   when. Beni is starting to work on this.
 - We discussed the thoughts regarding a beam test for the full-scale
   prototype. It looks like there may not be enough time and readout,
   but no final decision has been made. For now, we are pursuing what
   we can learn with cosmics and sources.

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.