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FDC Weekly Meeting

Date: December 11, 2008

Participants: Daniel, Bill, Mark S., Micah, Chuck, Roger

Next Meeting: December 18, 2008 @ 1:30 p.m.

Full-Scale Prototype Updates

- Procurements:

    * Rigid-flex assemblies:
       * Fernando and Roger have finished the design review and are now
         finalizing the language on the order specification and the 
         assembly drawings. The PR will be given to Elke in the next
         couple of days.
       * 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.
    * Wire QA studies:
       * The QA checks for the sense wires are complete.
       * Brian has prepared a slide for the SEM studies of the field wire
         and given it to the SEM folks. They will complete their work in
         the next few days. 
       * Brian will prepare a final QA report with photos and test results
         for all wires when all studies are complete.
       * Brian checked with the purchasing agent responsible for the
         wire order to find out what QA qualifications were part of this
         order if any. Apparently they were not part of the order. It is
         not clear what happened. Was this a miscommunication or a did
         somebody drop the ball?
    * G10 ring order status:
      * No new news. Expected delivery date is any day now. This order
        includes the G10 for all FDC wire and cathode frames.
    * 110IG Rohacell order status:
      * No new news. Expected delivery date is Dec. 17.  This order
        includes the G10 for all FDC wire and cathode frames.
 - 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.
 - Bill has completed a draft of a specification/tolerance document
   for the wire frames.
 - Bill has worked with the JLab machine shop to do some tests of the 
   system to do vacuum bagging on the G10/foam laminate. While things did
   not work fully has Bill had hoped, he declared that we are ready for
   preparation of the G10/foam laminates once the orders arrive. 
 - The test laminate that was made by Mark (consisting of G10/foam) was
   seen to be highly warped last week. This week it is flat as a board.
   Neat! The issue is due to humidity. We will modify the construction
   document to give some time for the frame to sit in vacuum to pull out
   all water before machining and assembling.   
 - The templates for cutting the foam core pieces have been completed in
   the JLab machine shop and are in our possession. Bill will look into
   having these pieces anodized (to make them more resistant to nicks and
   dents). We will also consider having their surfaces treated in a simple
   way to avoid oxidation.
 - We reviewed the remaining machine shop work for the wire frames. After
   construction of the G10/foam laminates is completed, these pieces will
   be machined for through-holes. These pieces will then be laminated to
   the PCB annuli using our vacuum bagging procedure on the construction 
   jig fixture.
 - The Phase 2 contract with IUCF for winding the full-scale prototype
   has now been signed by all parties.  Our window for getting the
   completed wire frames to IUCF is from the middle to end of Jan. 2009.
 - Kim has provided a draft of a procedures document for the Phase 1 and
   Phase 2 wire frame PCB component attachment. She has merged this
   document with Fernando's cleaning and handling document.  The document
   is being finalized with some additional language on soldering iron
   temperature vs. time profiles.  It must be completed before the
   start of the Phase 2 component soldering.

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
     * Bill has asked for some modifications to the specific tasks for
       the cathode edge cutter. DSC will work on the language and pass
       this on to Chuck for inclusion.
     * Copies of the timeline were handed out to folks for reporting on
       their work progress.
     * DSC will replace Micah's name on schedule with Mark S.'s name for
       all work required in 2009.
 - Bill has completed a draft of a specification/tolerance document
   for the cathode frames.
 - Bill has completed the design of the cathode edge cutting system. He is
   finalizing the fabrication drawings and then the procurement will begin. 
   Some of the parts actually have already been ordered and delivered to
   JLab. Some machining work is necessary and we are trying to figure out
   the quickest delivery/lowest cost option now. After assembly of the 
   system, we will work through a full test plan before cutting any of our 
   "real" cathodes.
 - Still waiting on an updated version of the cathode construction document.
   Bill has this now and will get back to it soon. This will need some
   priority soon.
 - Before construction of our first "real" cathode for the full-scale
   prototype, all tasks must be prototyped with final procedures! We will
   be making (at least) one more cathode mock-up using the final procedures.
   Note: The tensioning of the cathode will be done with a full cathode
   frame laminate, not just a G10 annulus. DSC will talk to Brian about
 - Minor design problems with the cathode tensioning system are being
   addressed with some work done by the machine shop. Some of the work
   has been completed (adding a filler piece on the aluminum jig plate)
   and others are in progress (associated with the arm holding the laser).
 - We need to begin considering construction of the cathode sandwich
   prototype. It may be that we will want to construct a prototype before
   making our first "real" cathode for the full-scale prototype. This
   discussion will take place next week. There may be issue with connecting
   the ground plane that will require study and machining of frames.
 - We looked at the ground connection prototype and will talk about it
   more at our next meeting (where more folks will be present).
 - Brian has cut off a piece of the 2-micron cathode prototype and put it
   into a mini-stretcher. Eugene and Brian found that the design of this
   tensioner (square with only 4 tightening bolts - 1 in each corner) was
   inadequate. It caused board puckering, resulting in different tensions
   in different portions of the board.  The mini-tensioner has been given
   to the JLab machine shop for modifications. The board will be tensioned
   to 400 N/m and the distortions of the electrodes parallel and perpendicular
   to the strips will be measured. Studies of the board distortion on this 
   real board material are crucial to our design approach. More to come soon.
 - Mark will perform some handling tests on the 2-micron board that will
   be typical during construction to ensure that we have techniques in
   place to reduce handling defects. More to come.

Cathode flatness measuring system

 - It was verified that the problems seen in the scan data presented
   last week by Micah were due to rail misalignment problems. The rail
   was reset and the granite table surface rescanned.  It seems that a
   rail misalignment still remains, although at about half the level
   it was at before.
 - The JLab Survey Group came in and surveyed the granite table. It
   is very flat (as it should be darn it). Details from their report
   were provided in a data document provided by Bill.
 - Micah showed some data from scans of the high-tension (600 N/m) cathode
   at 4 different rotation angles. See his talk slides for details. Presently
   Micah analyzed the data using a linear correction function for the
   rail misalignment. We discussed the preferred mode of actually
   subtracting the granite table measurement from the cathode data. This
   is a bit tricky now due to data handling. We may revisit this issue.
   There was a problem with the data that Micah acquired that he found
   that the frame was fully tightened down to the granite table. Micah
   will redo the scans.
 - Bill has asked for Micah to remeasure the granite table surface as
   a reproducibility check of the system.
 - Micah would like feedback from the FDC Group on what data we would
   like back from the scan.  DSC talked to David after the meeting and
   discussed two types of data: 1). data that shows the electrode
   surface bowing, which can be somewhat coarse in binning (say 1 in by
   1 in bins), 2). data on with finer grid size to look for sharp
   surface defects.
 - 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.
 - Documentation of the system continues. See the FDC wiki page 
   for details.

Spacer Design

 - Bill has declared that the spacer ring will have two o-ring grooves.
   This is the best solution (and most viable). He will move to have
   the machine shop prepare the polyethylene and poly propylene rings.
   These will be complete spacers, and thus, will include the o-ring
   grooves and the gas plumbing. Bill will also order the remainder of
   the material needed for the full-scale prototype.

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.

Gas System Design

 - Slava has worked on a preliminary layout of the gas handling system 
   for the CDC and FDC.  He provided two options for the FDC system design 
   that were essentially a basic version and a fancier version.  Slava's 
   design work was based on the original concept that Brian came up with 
   long ago.  We will continue the design work as we have time.


 - 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.