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FDC Weekly Meeting

Date: May 7, 2009

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

Next Meeting: May 14, 2009 @ 1:30 p.m.

Full-Scale Prototype Updates

 - Cathode Board Orders
    * Cathode boards: The cathode order delivery date has slipped a bit.
      The boards will be prepared next week and should be here at JLab
      by May 18 or so. Allflex is still considering the procedure of
      adding a second rinse stage to clear off developer and other 
      potential corrosive chemicals. Roger is awaiting word. Roger still
      has to specify shipping requirements. The JLab transport box is
      now at Allflex.
    * Cathode daughter boards: The order for the cathode daughter boards
      and ground boards (rigid-flex assemblies) is out. Roger has ordered
      60 of each type. Delivery expected within a couple of weeks. Roger
      still has to supply final set of Gerber files. Fernando has these
      now and will give official blessing.
 - Chamber Wire:
    * The SEM studies of our wires should be completed very shortly. This 
      includes a check of the ovality of our sense wire and the mass 
      spectroscopy reports. Stay tuned.  Brian will prepare a final QA report 
      with photos and test results for all wires when all studies are 
 - Soldering Work: 
    * Greg Arnold's group will not be available for our work until maybe the 
      end of May/beginning of June. It looks like we can get manpower if 
      needed through Chris Cuevas' group so that delays on the wire board 
      Phase 2 soldering and the connection of the rigid-flex assemblies to 
      the cathodes is not delayed.  We may need to borrow the wave solder 
      machine from Greg's group. More to come as schedules come into focus.
    * To avoid concerns with melting the epoxy on the cathode boards during
      soldering of the rigid-flex assemblies, we want to do a test to make
      sure that there are no problems. Mark and/or Brian will set this up.
    * Fernando was asked to finalize the component values for the preamp
      card addressing resistors for the wire frames and cathode frames.
 - We are sharing the clean tent with Hall B.  The Hall B folks will
   need about 2 to 3 weeks of time to finish their work.
 - The cooling clamp assemblies for the preamp boards are in our possession.
   There are enough pieces for the full-scale prototype.
 - Bill will put together the order for the o-ring material for the
   full-scale prototype.
 - Mark, Brian, and Bill have been asked to ensure that all parts 'n pieces
   needed for prototype construction are in hand. We may need some longer
   pins for the assembly jig and they will look into G10 pieces to hold
   our cathode frames flat.
 - Design planning: Eugene is working to justify the remaining FDC design
   work and costs to the CLAS12 project management. DSC, Beni, and Tim are
   helping to prepare the necessary documentation. Eugene will meet with
   management on Monday.
 - Fernando reported that the HV cable has been received and we are now
   waiting on the connectors. The signal cable and connectors are in hand
   are Mark S. will make the signal cables for the FDC and CDC prototypes.

Wire Frame Update

 - Status: The linear transducer has been returned to IUCF and reinstalled.
   IUCF rescanned the wire positions in the third plane and the trends in
   the measurements were identical, but the point-to-point spread was
   noticeably reduced. The level of improvement seems to be at the +/- 20
   micron level.
 - IUCF found other problems in the winding system including a bad 5V
   power supply and a bad op amp driver for the wire feeder. These have been 
   repaired and checked and the system is functioning.
 - There was a strong systematic in the wire positioning. It is believed
   that this is due to systematics in the stripe positions in the Moire
   pattern mask that has been seen. Alan Eads adjusted the wires to the
   stripe positions, but as the stripe positions are off from the ideal,
   this translated into wire offsets.
 - We would like to rewind the table for the last/fourth wire plane, but
   there is not enough wire to do this. IUCF will find a "good" section
   of the Moire mask and use this to adjust the wire positions. They will
   plan on gluing and soldering next week.
 - A no-cost contract extension has been completed until May 31, 2009.
 - We are presently planning to have Mark S. drive to IUCF the week of May
   18 to pick up the wire frames. Keith will give us a final date shortly.
 - IUCF will plan on winding the table with what wire remains after the
   fourth frame is off to continue to check out the system now that
   repairs of the electronics and refurbishment of the transducer are
 - Keith has been reminded that a budget estimate for production winding
   is part of the Phase 2 contract.
 - Bill will send Keith some information on which sections of the wire
   winding procedures document needs input from them to filling in holes.
   The start of this procedures document is included in Bill's IUCF trip 
   report (GlueX-doc-1229).
 - Bill has been updating the wire frame construction document based on 
   lessons learned from the prototype frames. The newest version is located 
   at /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. Please read it over 
   and give him feedback.
 - 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. He will get back to this work after the tagger review is done.
 - Mark and Brian completed work on the turntable for the soldering techs.
   This system has a magnifier mounted across it. Protective covers for
   the wires are nearly done.

Cathode Construction

 - We reviewed the cathode R&D timeline.
 - Progress updates:
     * The 8 cathode frame laminates and G10 annuli will be done in the
       machine shop on May 21.
     * Other JLab machine shop work: The aluminum clamp ring for the 
       tensioning facility will have its I.D. increased to give better
       access; One of the G10 tensioning rings will have its I.D. increased
       and will get a skim cut to remove old glue and Kapton; the thin G10
       rings that make up the remainder of the cathode frame laminates will
       have all the through-holes and gas holes added. These pieces will 
       also be done on May 21.
     * Some progress on the mechanical prototype. The power connectors
       have been soldered to the rigid-flex assemblies and the preamp card
       connectors have been added to the wire frame. Next week this system
       will be put together for design checks. This will include the cooling
       lines for the preamp cards.
     * Bill has been working on the cathode construction document. He will
       circulate a draft shortly. He has been tied up with the tagger review.
  - The cathode cutter is ready for action once the cathode boards arrive
    from Allflex.
  - The company that makes our 2 micron Cu board material will end production
    of this line in the next few months due to profitability issues. We are
    looking into purchasing the full amount needed (~1500 ft) for the
    full production run of the boards. The raw material will be stored in
    an inert environment until needed for construction. Roger is getting an
    estimate now for the material.
  - As the rigid-flex assemblies will be soldered onto the cathodes directly
    over a region where the Kapton is laminated to the G10 skin, we were
    worried about delamination that could occur due to the heat from the
    solder gun. A test was done and a rigid-flex assembly was soldered onto
    a test piece. Robustness/destructive tests are still planned as part
    of this work.

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

Stack Assembly Procedures

 - Brian agreed to start a draft of the stack assembly document. This 
   document should be in place before we get too far in the construction 
 - Bill has some design work to do to finalize the plans for stack
   compression. He is starting to think about this more.

Cooling System Tests

 - Fernando is in the process of writing up the results from his cooling 
   system studies.  Stay tuned for the GlueX note. He indicated that he
   is back to work on this document and it should be done shortly.
 - 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.
 - Brian has been charged with putting together a first draft for the
   package construction/assembly document. We want something in place
   before assembly of the full-scale prototype.

Cosmic Ray Test Stand

 - We will be moving the FDC cosmic ray test stand from the Test Lab back
   to the EEL building. Beni has come up with plans for the room layout in
   EEL 126. The big shelving unit has been removed from the room as well as
   a number of Detector Meister cabinets. The room is being rearranged as
   per Beni's master plan. The test stand should be moved over to EEL by the
   end of the month. We may be able to get the Hall B techs to help out.
 - 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.
 - Beni has started a bench test plan for the full-scale prototype and
   we discussed his preliminary document briefly. He will circulate it
   for feedback and we will continue to flesh it out. We want to make sure
   that we do some checks of gas leakage with the prototype. We agreed that
   the best procedure would be to use the P5 gas mixture (non-flammable).
   Simon will start putting together the OSP safety paperwork for this task.
   Bill will start to think about designing a system to rotate the prototype 
   from vertical to horizontal. This will proceed after the tagger review.
 - 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.