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FDC Weekly Meeting

Date: January 22, 2009

Participants: Daniel, Simon, Brian, Mark I., Mark S., Bill, Beni, Fernando, Micah, Elke, Dave, Roger, Eugene

Next Meeting: February 5, 2009 @ 1:30 p.m.

Full-Scale Prototype Updates

 - Elke raised the issue of signed drawings for the FDC prototype. She
   asked that we follow established lab procedures for getting drawings
   signed. This entails that at least one person outside of the work
   being done look them over. Bill will talk with Tim about making this
 - Procurements:
    * Roger is waiting on a call back from the company making the rigid-flex
      assemblies. He stated that our order should be here by the end of this
    * The replacement order for the Rohacell should arrive any day now.
      Bill has had some trouble getting in contact with the company, but
      he will follow up on this.
 - Wire QA studies:
    * Brian has provided samples of our sense and field wires to the
      SEM folks, they will complete the mass spectroscopy analysis and
      get back to us shortly. 
    * Brian will prepare a final QA report with photos and test results
      for all wires when all studies are complete.
    * Beni circulated an updated draft of the wire QA specifications
      based on my earlier document and additional feedback from Steve
      Christo. DSC will look over and give feedback.
 - 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, 
 - The Hall A folks have inquired about use of the clean tent. Brian has
   had some discussions, but not enough is known about their time line.
   Brian will send the Hall A folks to DSC to finalize the plans.


 - Fernando has posted a new GlueX document entitled 
   Calibration of the CDC and the FDC Readout Electronics.
   Folks should look this over and we can talk about it at a future 
   tracking meeting or FDC meeting.

Wire Frame Construction

 - All Rohacell/G10 laminates have come back from the machine shop and
   are within the promised specifications.
 - Two wire frames have been successfully laminated to the PCB annuli and
   a third is in the vacuum-bagging facility at present. The fourth
   frame will be done tomorrow.
 - All completed frames have a thickness variation of within a mil! This
   is outstanding
 - The last step to complete the wire frames is to use epoxy to seal the
   Rohacell along the inner diameter and the outer diameter, as well as
   the through-holes. We should be ready to start packing the frames (and
   the sense and field wire spools) into the shipping crate on Tuesday of
   next week.
 - Brian/Mark will alert shipping and receiving so we can try to get the
   crate to IUCF by the end of next week.
 - Elke has sent email to Vladimir Derenchuk with an official schedule
   update and to request information on when they will be ready to start
   working.  She also alerted them that we want Bill there for some portion
   of the work.
 - Kim needs to complete the PCB stuffing/cleaning document. This should
   be done by the middle of February.  She has made a request for the
   relevant information from Fernando so that she can finish this document.

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
 - Progress updates:
     * The cathode edge cutting system has been assembled. Bill is not
       fully satisfied with the clamp design but thinks he has a satisfactory
       work around. Mark will put some attention on doing test cuts after
       the wire frames are done and gone.
     * No progress on completing the cathode construction document. Stay
     * The laminates that were made up for the cathode frames for the 
       full-scale prototype were made and found to be too thin in places.
       Mark will make up another pair with improved QA selection for the
       foam. These are needed in the shop for machining ASAP as the window
       given to us by Casy is closing.
     * Brian will start laying up 2 sets of cathode planes for the
       full-scale prototype. He will use blank Kapton for this. He will
       not need the edges cut with the new system.
     * Eugene stated that he believes the average cathode tension should
       be set to 500 N/m after his most recent analysis.
     * We discussed more about the artwork distortions on the cathode boards
       that will result from the tension. We expect no more than 3 mm across
       the strips and maybe another 0.5 mm at the tape joints. Instead of
       worrying about the complications of using scaling factors in the
       artwork, we will opt for the simplest solution. Allow for the 
       stretching and correct for the increased strip pitch in software.
       To proceed to the next step, Roger will work to modify the board
       design to allow for appropriate clearance around all through-holes
       to accommodate this stretching. The connections for the rigid-flex
       assemblies have enough slop for shifting the connection point to
       the cathode board.
     * Roger has started dialog with the cathode board house. We need to
       finalize exactly what we plan to order. Probably 6 more sets of
       2 micron Cu boards. We currently feel that we will not have to
       resort to using 5 micron Cu boards given the flatness of the boards
       in the first order.
     * We discussed that the time line for the next cathode order is about
       1 month. Roger is aware of this and will start on the board redesign
     * We discussed plans for using an optical system to measure the
       cathode board distortions after they have been tensioned. Presumably
       we could use the horizontal mill in the machine shop using their
       camera system. This will most likely be needed in about 6 weeks.
     * Bill raised a clearance issue on the space between neighboring
       cathodes. The ERNI power/address connector on several boards is in
       conflict with the positioning of nearby cathode daughter boards. Two 
       solutions were discussed, the first is to use thicker Rohacell in the 
       cathode frames to increase separation, the second is to redesign the
       cathode daughter boards to rearrange the layout. Roger will look
       into this last option.

Cathode flatness measuring system

 - Documentation of the system continues. See the FDC wiki page for details.
 - Drew has offered to use Detector Meister money to buy another laser
   for the FDC effort so that we don't have to share one between the
   tensioning facility and the flatness facility. Brian will put the PR
   together.  We will get another computer that Brian has so that we can
   have two separate systems.

Spacer Design

 - Bill has completed the prints for the spacer construction and will pass
   them onto the machine shop shortly.
 - The material order will arrive soon. This work is not super high priority
   and we will use it as filler work in the machine shop.

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.