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FDC Weekly Meeting

Date: December 18, 2008

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

Next Meeting: January 8, 2009 @ 1:30 p.m.

Full-Scale Prototype Updates

 - Procurements:
    * Rigid-flex assemblies: 
      * The PR has been given to Elke and was signed as of today. The parts 
        should arrive by roughly the middle of January.
      * The boards will be given a cursory QA checkout upon arrival and then 
        be test fitted into the cathode frames. Upon successful tests, the 
        remainder of the order will go out.
    * G10 ring order status: 
      * The order has arrived and has been placed on the shelves in EEL 126.
    * 110IG Rohacell order status:
      * Bill contacted the company and the order was delayed. It will
        arrive at JLab this year, but after the start of break. Mark or
        Brian will talk to shipping and receiving to find out what will
        happen if the order arrives during break.
    * Wire QA studies:
       * The QA checks for the sense wires are complete.
       * The W&M folks have not yet gotten started on the field wire tests.
       * DSC will send Brian info on the SEM studies of the Hall B CuBe wire.
       * Brian will prepare a final QA report with photos and test results
         for all wires when all studies are complete.
 - Mark S. is also responsible for upkeep of the list of procurements for
   the full-scale prototypes.
      * Location: M Drive/halld/Electronics, or for more sophisticated folks, 
 - Bill is working to put the local HV connectors selected by Fernando into 
   the 3D CAD model and to detail how they will be attached (as they are 
   quite massive).  Bill will get back to this work when he has a chance.

Wire Frame Construction

 - An updated draft of the wire frame assembly document has been prepared
   and is ready for review: Wire frame assembly document. All comments 
   should go to Bill as he works to prepare a modified draft. DSC provided 
   Bill with comments.  All FDC procedure documents should ultimately find 
   their way to the GlueX portal.
 - See the FDC wire frame specification/tolerance document.
 - The JLab machine shop has completed additional machining work on the
   vacuum bagging jig. It should now be back in our possession.
 - Brian and Mark will work to complete a humidity test of our G10/foam
   laminate in a dry box.  This work should be completed soon so that
   the vacuum bagging steps can be finalized in the procedures document.
 - The templates for cutting the foam core pieces have gone out to be
   anodized to improve surface hardness.  They will be back shortly.
 - Elke has officially notified IUCF of our window for arrival of the
   four wire frames. The window is the last two weeks of January 2009.
   Brian indicated that Casy has a job coming into the shop in the third
   week of January that will need the horizontal mill. Thus we have to
   be done with all machine shop work for the wire frames by then.
 - Kim needs to complete the PCB stuffing/cleaning document. This should
   be done by the middle of February.

Cathode Planning

 - We reviewed the cathode R&D timeline. Folks are reminded to pass on
   progress updates to Chuck every Wednesday.  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
     * A couple of problems were repaired in the official schedule and a
       few tasks clarified and added.  Please refer to the latest version
       for reporting. Talk to DSC or Chuck if you have any questions.
 - See the FDC cathode frame specification/tolerance document.
 - Mark has been assembling portions of the edge cutting system. A series
   of parts n' pieces are now being machined at FSU and will be sent to
   JLab this year. After assembly of the system, we will work through a 
   full test plan before cutting any of our "real" cathodes.
 - Due to other priorities, the construction document for the cathode
   frames and cathode sandwiches has not gotten very far. We should plan
   to have a draft of this document available before the onset of construction
   of the first 5-micron Cu board in the second half of January.
 - The cathode R&D plan in the first part of January will focus on
   construction of a full cathode sandwich. This will include ground
   connections to the cathode foils and ground connections to the ground
   plane. After this work is done, we can proceed on the 5-micron Cu
   cathode (presuming the edge cutter is up and ready to go).
 - Minor design issues with the cathode tensioning system are being
   addressed with some work done by the machine shop. The pieces are now
   done in the shop and are awaiting pickup.
 - We focussed on the attachment of Roger's rigid-flex assembly to the
   cathode frame. Bill was worried about the difficulties of having a
   cut-out on the G10 skin and tolerance issues with attaching the
   Cu fingers on this board with the cathode board solder pads. We have
   decided to do away with the cut out and epoxy Roger's boards to the
   G10 frame. If this proves problematic, we will revisit the issue later.
 - The first attempt at using the mini-tensioner with a sample of our
   2-micron Cu board failed as the system only had four tensioning screws.
   This did not allow a uniform tension to be set. The machine shop added
   4 additional screws to the system. Brian prepared a blank Kapton piece
   and Eugene set and measured the tension. He was satisfied that the system
   is ready for the ready cathode board material. Brian and Eugene should
   complete the distortion measurements this week using a tension of 400 N/m.
 - We discussed the limitations of our current cathode tensioning system.
   The best way to try to set a uniform tension is to use a torque wrench
   on all bolts. We will try to make due with this system as it is for the
   full-scale prototype cathodes. We have a preliminary design from Bill
   to upgrade this will air cylinders and springs, but that will wait for
 - Mark performed some handling tests on the 2-micron board that involved
   lifting with a suctioning system. We decided ultimately to go with a
   lower-tech solution. This will be developed and tested in January 2009.
   More to come.
 - We discussed a bit more the connection of external grounds to the
   cathode boards and the ground plane. Bill believes the best approach
   is to leave additional material at half a dozen places on the O.D. and
   to secure these pieces for connections like he has designed already.
   More to come.

Cathode flatness measuring system

 - Micah completed additional scans of the high-tension cathode board
   (600 N/m version) and the granite table.  See his slides for more details.
 - Micah has begun the transfer of knowledge on cathode flatness
   scanning to Mark S. Mark S. demonstrated his expert status by
   performing several scans himself.  More training to be done to let
   Mark know how to analyze the scan data.
 - Documentation of the system continues. See the FDC wiki wiki page 
   for details.

Spacer Design

 - Mark has done some tests of attaching Kapton gas inlets and outlets into 
   the holes on a prototype spacer frame using an injection molding process.
   He believes that he has worked the kinks out. We want to check to make 
   sure the instant adhesive employed will be chamber safe.
 - The first two frames will go to the shop shortly and Bill will order the
   remaining stock needed.

Stack Assembly Procedures

 - DSC, Brian, and 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.

Small-Scale Prototype

 - We will be moving the FDC cosmic ray test stand from the Test Lab back
   to the EEL building. This move should be completed in the next 6 months
   or so.

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.