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FDC Weekly Meeting

Date: November 6, 2008

Participants: Daniel, Simon, Fernando, Mark I., Mark S., Herun, Roger, Drew

Next Meeting: November 13, 2008 @ 1:30 p.m.

Full-Scale Prototype Updates

 - Procurements:
    * Roger has finished the design work on the cathode rigid-flex assemblies.
      He still has some minor work to do on the ground rigid-flex assemblies.
      He has been in contact with Allflex and is working out details on the
      specifics for the order.  The plan is to order two runs of boards -- a
      first run of 5 to 12 prototypes, followed by a production run of about
      70 boards.  The first run is to ensure the boards fit in position given 
      their tolerances.  A quote has been received from Allflex of about $5k
      for everything.  The PR for the first run should be ready for Elke to
      sign in about a week. Remember that before the design work is considered 
      done, Fernando will double-checking the drawings.
       * Roger should communicate the board stuffing needs with Kim and she
         can arrange for the work in-house.
    * The order for the sense wire has arrived.  Mark S. is making plans to
      test the wire according to our requirements (surface plating check in
      the SEM and strength test).  Mark has been given a copy of the wire
      specification document prepared by DSC.  The field wire order is
      expected any day now and it too will be tested.  Brian will work with
      Mark to train him on how to handle the wire spools to prevent
      damage and contamination.
    * G10 ring order status:
      * Brian has verified that the order for the G10 rings has gone out
        the door.  Expected delivery date is roughly 4 weeks.
    * 110IG Rohacell order status:
      * Bill checked that the Rohacell order has gone out.  The expected
        delivery date is Dec. 17.
 - Mark S. will take responsibility for watching over the FDC component
   stores and keeping the database up to date.  Kim will provide him with
   the excel spreadsheets for what we now have.  All boxes are sitting in
 - 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.
 - Kim has placed the procurement spreadsheet on the mdrive.
      * 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.
 - Additional prototyping work by Mark S. has led us to essentially finalize
   our PCB annulus lamination technique.  A chamber-safe epoxy choice has
   been made (a type of JB weld adhesive) and studied to ensure that it is fully 
   controllable under gluing pressure (no voids or epoxy on the board surface).  
   Mark S. has constructed a simple notched scraper tool to control how much 
   epoxy is in the lap joint.  The prototypes that Mark S. brought looked
   beautiful. The machine shop is working on manufacturing a simple clamping jig 
   designed by Bill.  After some low-level design verification, this system will 
   be used to glue up the PCB annuli for the full-scale prototype wire frames.  
   This gluing should take place next week.
 - A new epoxy application system for laminating the G10/Rohacell layer to the
   PCB layer has been devised that gives a very satisfactory control of the
   epoxy during the vacuum-bagging procedure.  A soft foam roller has been
   used that is dipped in an epoxy reservoir.  The epoxy is then rolled on to
   the PCB boards.  In the past, we used a hard-rubber fingerprint roller with
   epoxy poured onto the PCB.  The new system has been shown to give fully
   satisfactory results to date.  A few more tests are planned to study the
   seepage of epoxy through the holes in the circuit boards before declaring
   success.  The prototypes that Mark S. brought looked beautiful.
 - The JLab machine shop is in the process of modifying one of our aluminum
   jig plates to work as a vacuum table.  This will be done very shortly and
   will be tested out.
 - Mark S. will modify the wire frame construction procedures document after
   things are a bit further along.  He will take photographs of the necessary

Cathode Planning

 - The specification/tolerance document for the cathode frames is being worked
   on.  It will be circulated shortly.
 - Mark S. will check on the cathode boards in the storage box to make sure that 
   there are no problems.  This still has not been done yet.  However, there
   has been regular checking on the nitrogen source.
 - Fernando has communicated with the W&M SEM folks and will be heading up another
   check of the surface deposits on our sample cathode board.  More to come soon.
 - Bill has nearly completed the design of the cathode edge cutting system.
   He will need another week (when he gets back from vacation next week) to
   complete the fabrication drawings.  We will then have a procurement window
   for some parts before we can test it out for tolerances.  More soon.
 - Cathode flatness measuring system:
     * Micah is doing some test measurements now.  He has defined a grid
       size of 1 in by 1 mm that allows a cathode scan to be completed in
       15 minutes or so.
     * Micah will do a measurement of the surface flatness of our granite
       table and then complete the cathode flatness measurements with our
       high tension cathode prototype.  He expects to have results early
       next week.
     * Waiting on results of measurements.  Presumably some have been completed
       but no report is now available.
 - Brian has prepared a first draft of a cathode construction document.
   Bill is working on expanding it with available pictures.  DSC passed
   his comments on to Bill to be added.
 - DSC and Bill have prepared a short-term cathode R&D schedule (derived from
   the full schedule that was prepared several months ago).  It has been
   circulated to Elke, Brian, and Drew for feedback.  We will need to have a
   meeting to figure out how much time we can get from Brian to work on this.
   The first work to be completed is to update the cathode tensioning system.
   This will lead to construction of a cathode prototype or two that will be
   used to finalize the cathode tension choice and the artwork distortions.
   Roger will have some redesign to do (most likely) to be sure that the
   board stretching does not lead to problems with the through holes.  DSC
   stated that we will use one set of our new cathode boards to make a prototype.
   However, before this happens, we will work with blank Kapton sheets and
   our existing dummy boards to finalize all techniques and requirements.
 - We discussed a bit more about the glue strip design. Mark S. and Brian will
   study using 2-in Kapton tape with Hysol adhesive applied with the new soft
   rollers.  There is hope that this may work and eliminate our worries about
   the glue strips.
 - Just before Bill left for vacation he had come up with a new idea for
   attaching the external grounds to the cathode boards.  We will discuss this
   more fully with Fernando when Bill returns.

Full-Scale Prototype Wire Winding

 - The IUCF folks modified the dates in the Phase 2 contract and this
   was O.K.'d by JLab.  Looks like we are days away from a signed contract.
 - We are going to struggle from our end to get the wire frames to IUCF
   before the end of the year.  1 week to complete orders, 4-ish weeks
   for bits and pieces to arrive, 3 weeks to manufacture 4 frames, 2 days
   for shipping.  (Heavy sigh).
 - The Moire pattern masks have been received by IUCF.  They were inspected
   and found to be satisfactory.
 - IUCF sent us back our transport box for the wire frames.  Brian has placed
   it in a secure (undisclosed) location.

Spacer Design

 - Bill reported that we have a sheet of polyethylene and a sheet of
   polypropylene.  The blue print 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.

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 will revisit this problem by taking some
   new pulser calibration data to see if this makes the apparent problem
   go away.

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.