Minutes-4-9-2009

FDC Weekly Meeting

Date: April 9, 2009

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

Next Meeting: April 16, 2009 @ 1:30 p.m.

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Full-Scale Prototype Updates

 - Cathode Board Orders
    * Cathode boards: The PR has been signed and is in the JLab Procurement
      Office. Bill provided Roger a final list of changes to the boards that
      will be incorporated. Roger has sent these on to Allflex and is
      awaiting feedback. Roger will finalize with the sales representative
      the final rinsing procedure. We will also send Allflex our transport
      box shortly. Delivery is being specified as 6 weeks, but the Allflex
      representative believes it should actually be closer to the first week
      of May. The final order will have 7 sets of 2 micron Cu boards and 1 
      set of 5 micron Cu boards.
    * Cathode daughter boards: the PR is essentially ready and will go
      out shortly. Turn around for the order will be less than 2 weeks.
 - Chamber Wire:
    * We are waiting for the W&M SEM folks to finish training their folks
      on the new SEM and then they will finish our wire QA checkout. Brian 
      will prepare a final QA report with photos and test results for all 
      wires when all studies are complete.
 - Soldering Work: Greg Arnold's group will not be available for our work
   until the middle of May. This will probably be O.K.. We need to make
   sure that this work is planned and coordinated.

Wire Frame Update

 - Status: The linear transducer has finally been sent off for refurbishment
   It should be back and reinstalled in about 2 weeks.
 - Folks who have not read Bill's IUCF trip report (GlueX -doc-1229)
   should look it over and provide feedback.
 - 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. The newest version is located at
   /u/group/halld/Engineering/PRELIMINARY DOCUMENTS.
 - Brian will gather all the bits n' pieces for a write-up on the wire
   electroplating and post his document on the mdrive for feedback.
 - Bill is now designing the jig for the wire electroplating operation
   and it will be ready for submission to the shop at some point in the
   future. This is not a high-priority job at the moment.
 - 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.
 - Mark will test fit the wire frame protective cover to be sure it is
   idiot-proof and does the required job.

Cathode Construction

 - We reviewed the cathode R&D timeline.  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:
     * Frame construction has now begun in earnest and should be done by
       the end of next week. All Rohacell pieces have been cut and 3 foam
       annuli have been put together. One G10/foam laminate has been made.
       Bill will communicate all details to Eugene so that we can arrange
       to have the machine shop work done by the second week of May. We
       plan on making up 8 cathode frames.
     * The second 5 micron Cu board was attached to our last complete
       support frame and is stored flat in the Lucite box. This board may
       be used in the full-scale prototype.
     * The first 2 micron Cu board was laid up. There were some issues with
       epoxy seepage onto the face of the boards. We discussed an alternative
       procedure to eliminate this problem and it will be tried out on the
       next 2 micron Cu board.
     * The 2 micron Cu board was put into the tensioner for Eugene to work
       on. The cathode was stretched to 450 N/m. The same pressure by the 
       springs produced 650 N/m for the 5 micron Cu cathodes. There is a 
       "gradient" along the strips 370-500 N/m, see sample 9 in
       http://www.jlab.org/~gen/gluex/Foil-tension-2.xhtml.
     * Due to work on other things, the attachment of the rigid-flex
       assemblies to the cathode sandwich mechanical prototype has not
       been completed yet. We discussed again what needs to be done and this
       work will be done shortly (I promise).
     * Bill has been working on the cathode construction document. He will
       circulate a draft shortly.
 - We will need to make up the metal cooling bracket pieces that attach to
   the preamp cards and lock the Cu cooling loops to the readout. We will
   go with aluminum for the prototype tests and hope that they are good
   enough. If necessary, they can be made from copper.
     

Cathode Flatness Measuring System

 - Documentation of the system continues. See the FDC wiki page for details.
 - In order to make decisions on the tension settings for the cathode planes,
   we want to understand the surface flatness. We will want to scan our
   5 micron Cu cathode and then to scan our 2 micron Cu cathode once we have
   a frame to mount it to.  This is important input on the minimum tension
   values.

Stack Assembly Procedures

 - 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.

Documentation

 - 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. Beni is working on designing the room layout in
   EEL 126. The move of the cosmic ray test stand from the Test Lab does
   not need to happen in April as the planned magnet tests have been
   detailed for the time being. Still, we need to get things over to EEL
   for testing.
 - We still have some mysterious behavior with the small-scale prototype
   response with wiggles in the X vs. Y distributions that need to be
   understood. We decided to have a separate meeting to discuss what work
   we would like to do on the small-scale prototype.
 - 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.
 - For the full-scale prototype tests, we will have roughly 30 preamp
   boards stuffed (to be shared among everyone), 3 125 MHz FADCs, and
   "plenty" of TDCs. We need to flesh out a plan for who gets what and
   when. Beni is starting to work on this.
 - We discussed the thoughts regarding a beam test for the full-scale
   prototype. It looks like there may not be enough time and readout,
   but no final decision has been made. For now, we are pursuing what
   we can learn with cosmics and sources.

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.