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FDC Weekly Meeting

Date: November 13, 2008

Participants: Daniel, Simon, Brian, Micah, Bill, Fernando, Mark I., Mark S., Herun, Elke, Eugene, Chuck

Next Meeting: November 20, 2008 @ 1:30 p.m.

Full-Scale Prototype Updates

 - Procurements:
    * Roger has gotten quotes from Allflex on the rigid-flex assembly
      order.  He will pass the cathode daughter board drawings to
      Fernando for final inspection.  The PR for these boards (for the
      qualification run) should be ready in a couple of days.  Roger will
      hold off on order the ground rigid-flex assembly boards in the first
       * Roger should communicate the board stuffing needs with Kim and she
         can arrange for the work in-house.
    * Mark S. and Brian have been working to test the sense wire spool that
      arrive two weeks ago.  They have prepared samples for the SEM checks
      and have done some strength tests following the outline in our wire
      specification document.  Mark S. and/or Brian will prepare a baseline
      report for comparison with all future orders.  
       * As it was not clear if the contract depended on our qualification
         tests, Brian will follow up with the procurement folks to find out.
         We definitely need our qualification tests built into the order.
    * The order for the field wire just arrived and Mark S. and Brian will
      start on the qualification checks.
    * G10 ring order status:
      * No new news. Expected delivery date is roughly 3 weeks.
    * 110IG Rohacell order status:
      * No new news. Expected delivery date is Dec. 17.
 - Mark S. has taken responsibility for watching over the FDC component
   stores and keeping the database up to date.
 - 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.
 - Brian and Bill will send their procurement information for the full-scale 
   prototype to Mark S. who will update the excel file.
      * Location: M Drive/halld/Electronics, or for more sophisticated folks, 
      * Folks should fill it out in the given format.

Wire Frame Construction

 - We have settled on a thickness tolerance for the wire frame of 8 mils to 
   match the thickness tolerance for the cathode frames. DSC and Bill are
   working to complete a specification/tolerance document for the wire
   frames for circulation.
 - Mark S. has done quite a bit of prototyping with the wire frame construction
   during the past week.  This includes finalizing the tooling and assembly
   procedures for laminating the print circuit board ring, studying epoxy
   seepage through the circuit board holes, making the G10/foam laminate.  All
   tests were very successful and it looks like all procedures are now essentially
   final.  We still need to very that the JLab machine shop can mill the 
   G10/foam laminate to the tolerances that they quoted us.
 - Mark S. and Brian are presently using the clamp bar assembly designed by
   Bill to lay up the first print circuit board annulus.  After this is
   fully inspected and vetted, they will proceed to make up the remaining
   three annuli.  The 4 rings will be wrapped and stored away until they
   are needed.
 - Mark S. will modify the wire frame construction procedures document after
   things are a bit further along.  He will take photographs of the necessary
 - We think we have a signed Phase 2 contract in place with IUCF, but we
   have not received final word from either end.

Cathode Planning

 - DSC has put together a modified R&D plan for the cathodes.  Chuck is
   putting this into FastTrack now and it will be circulated shortly.  Folks
   should look this schedule over carefully, especially those areas where
   your name is listed.  Brian will be responsible for defending the progress 
   on this plan, including all work done, delays encountered, successes, etc.  
   He will work with DSC to keep the schedule up to date.  He will defend the 
   work timeline at each FDC meeting.
 - The specification/tolerance document for the cathode frames is being worked
   on.  It will be circulated shortly.
 - Mark S. checked on the cathode boards in the storage box and they have not
   disintegrated.  He will also regularly check the pressure in the dewar and
   replace it when necessary.
 - Fernando reported on the additional SEM studies of the dark spots that were
   on the cathode prototype board from Allflex.  The dark spots are most
   likely copper oxide.  There is still not a great answer as to why they
   seem to have a higher resistivity. We could study how the spots charge up
   in the SEM, but may delay this as it is not a major issue now, just a 
   point of curiosity.
 - Bill has nearly completed the design of the cathode edge cutting system.
   He will need another week to complete the fabrication drawings and then the
   procurement will begin. More to come.
 - Cathode flatness measuring system:
     * Micah has completed a scan of the granite table surface and it looks
       like there is a misalignment problem with the system at the level of
       1 mm across the table surface. Bill will look into this and make
       adjustments.  Whatever system problems remain can be used as a baseline
       measurement that can be subtracted from the measurements for the
     * Micah has measured the high tension cathode in one orientation, but has
       not accounted for the misalignment issues yet. More to come.
 - Still waiting on an updated version of the cathode construction document.
   Bill has this now and will get back to it soon.
 - Mark S. and Brian have done some studies of making their own Kapton tape
   for joining the cathode panels.  Earlier prototypes look good, but studies
   are still in progress.  They are laying up three panels of our dummy
   cathodes presently. They will then move on to do some load testing. Eugene
   will help out with the tension measurements.
 - Bill laid out an idea that he had for connecting the external ground to
   the cathodes.  He will discuss this further with Mark S. and have him put
   together a prototype or two to see if it works.  More to come.

Spacer Design

 - Bill reported that we have a sheet of polyethylene and a sheet of
   polypropylene.  The blueprint for construction of the space frame is
   ready for submission to the JLab machine shop.
 - Bill is in the process of evaluating two adhesives for attaching this
   frame directly to the cathode boards.  This will eliminate one o-ring
   groove on these spacers.  More to come.

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.
 - 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 should be completed before the
   start of the Phase 2 component soldering.

Small-Scale Prototype

 - ASIC specifications for the dynamic range have now been completed for both
   the CDC and FDC.  Fernando is now communicating all details to Mitch
   Newcomer to finalize the design before submission.  The hope is to have
   submission for the beginning of December.  If we are not ready by then, the
   submission will slip into 2009.
 - We still have the lingering issue of the problematic x-y plots from the
   2-micron Cu cathodes.  Simon looked at data that was collected and remade
   the picket fence plots. Details are given in the FDC Log Book.
   Using a better pulser calibration run, he managed to remove the lion's 
   share of the wiggles, but they are still there at a lower level.  More
   thought is needed on this.

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.