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FDC Weekly Meeting

Date: March 19, 2009

Participants: Daniel, Beni, Brian, Mark S., Mark I., Kim, Eugene, Fernando

Next Meeting: March 26, 2009 @ 1:30 p.m.

Full-Scale Prototype Updates

 - Cathode Board Orders
    * Cathode boards: Roger received price estimates from Allflex. The
      remainder of the cathode order for the full-scale prototype will
      be about $13k. The design work on the boards is done and Roger should
      have the cathode board PR to Eugene by Monday or Tuesday of next
    * We have seen evidence of corrosion on both the 2 micron Cu and
      5 micron Cu boards. Mark has taken photographs and will have Greg
      Adams take some more. Next week when Simon comes back, we will compare
      the original board photographs with the latest to see if there is
      any evidence of corrision since the boards arrived. Roger has
      already had some communications with Allflex on this, but we will
      provide them more information shortly. Allflex has already proposed
      adding a second deionized water rinse in the manufacturing process
      to remove any additional developer. More to come.
    * Cathode daughter board: The board is design is done and checked. This
      order will go out shortly after the cathode board order is complete.
 - Chamber Wire:
    * Brian talked to the SEM folks and their new machine has arrived.
      The operators are getting trained and they should be ready to complete
      our wire measurements in the next couple of weeks.  Brian will prepare
      a final QA report with photos and test results for all wires when all 
      studies are complete.
 - Mark S. is responsible for upkeep of the list of procurements for the
   full-scale prototypes.
      * Location: M Drive/halld/Electronics, or for more sophisticated folks, 

Wire Frame Update

 - Status: Two wire frames (P4 and P1) have been wound. A series of
   tension measurements and position measurements have been completed and
   the data has been transmitted to us. 
   * The tension measurements for both the sense and field wires appear to 
     be reasonably within our 5% tolerance specification after we account 
     (qualitatively) for the wire load distortions of the wire frames on the 
     strongback. Bill wants to do some better FEA modeling to understand
     the wire frame distortions.
   * The position measurements show a systematic issue that gives the same
     behavior on both wire planes. After investigation, two issues have
     arisen. The first is that there is a plastic seal/covering on the
     linear transducer that is broken and aged right at the position where
     the position anomalies appear. Also, there appears to be a discrepancy
     between the encoder data at the readout computer and at the readout
     electronics. We do not believe that we have accurate measurements
     for the wire positions. IUCF believes that the true wire positions
     are better than the position data reveals. This is based on studies
     with the Moire pattern mask.
   * The third wire frame is being glued today and will be soldered
     tomorrow and the fourth wire frame will be glued and soldered in the
     first part of next week.
   * The company that made the linear transducer still exists and can
     refurbish the piece for $1.5k and claim a 7 business day turn around.
     We have given IUCF the go-ahead to have this work done and charged
     to the Phase 2 contract. Bill feels that this is essential to do.
 - Bill has been updating the wire frame construction document based on 
   lessons learned from the prototype frames. He is working to incorporate
   some more relevant photographs. A new version will be posted when his
   work is done.
 - Brian will be working on fine-tuning of the wire electroplating process
   using one of the full-scale wire planes from Phase 1. This work will
   take place on Tuesday. Brian will produce a procedures document with
   photographs of each step for this work.
 - The bearing for the rotatable platter for the Phase 2 soldering is in
   hand. Bill will complete the design and get the drawings to the shop
   shortly after his return.

Cathode Construction

 - We reviewed the cathode R&D timeline.  We did not have an updated
   schedule to go over as both Chuck and Bill are away this week.  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
 - Progress updates:
     * All cathode boards from the first order have been trimmed. The
       work was deemed quite satisfactory. We should prepare a procedures
       manual for this work including our lessons learned.
     * The G10 pieces for the cathode frames are on order and should arrive
       at JLab within 2 weeks.
     * As we don't have the associated frames, we decided to go ahead and
       make up 3-piece cathode panels and put them in storage. So far, one
       5 micron Cu board panel has been prepared. It will be moved to
       storage this afternoon. Work on further panels will continue this
       week and next.
     * We will use Roger's sample cathode daughter boards with the mechanical
       cathode sandwich prototype to study the clearance and space between
       neighboring cathodes. This will happen next week.
     * 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.

Stack Assembly Procedures

 - We 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.

Cosmic Ray Test Stand

 - We will be moving the FDC cosmic ray test stand from the Test Lab back
   to the EEL building. This move should be probably take place in April.
 - We still have some mysterious behavior with the small-scale prototype
   response with wiggles in the X vs. Y distributions that need to be
 - We would like to put together a bench test plan for the full-scale 
   prototype within the next couple of weeks. This preliminary test plan 
   will be used to provide information on what test stand fixtures to 
   support the chamber we will require. Bill can then work on the design 
   and get things prepared in the shop.  Also, we would like to layout a 
   design for the electronics before too much longer so that we can reduce 
   time from when the full-scale prototype is constructed to when we get 
   into the test plan.

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.