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FDC Weekly Meeting

Date: May 14, 2009

Participants: Daniel, Mark S., Simon, Mark I., Fernando

Next Meeting: May 21, 2009 @ 1:30 p.m.

Full-Scale Prototype Updates

 - Cathode Board Orders
    * Cathode boards: The cathode boards are being prepared this 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 
      has prepared a draft of the shipping requirements and will pass this
      on to Allflex.
    * Rigid-flex assemblies: The order for the rigid-flex assemblies
      (readout + ground boards) is out. Roger has ordered 60 of each type. 
      Delivery expected within about a week.
 - 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: 
    * Fernando's group will handle the Phase 2 soldering work for the
      wire frame boards. This work should be able to begin on May 22 if
      Mark S. gets back from IUCF on schedule. DSC has contacted Kim to
      see if we can get the soldering equipment from Greg Arnold for this
    * DSC contacted Kim to set up Greg's group to do the soldering for
      the rigid-flex assemblies (preamp connectors + addressing resistors)
      in early June. The cathode soldering work should be ready to proceed
      by the third week of June.
    * To avoid concerns with melting the epoxy on the cathode boards during
      soldering of the rigid-flex assemblies, a test was carried out. There
      were no problems whatsoever mechanically. The issue was the lack of
      control of the height of the solder joint. This needs to be looked into
      to develop better controls.
    * Fernando was asked to finalize the component values for the preamp
      card addressing resistors for the wire frames and cathode frames.
      This work is in progress.
 - 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. We need to work
   out a reasonable schedule for our work in the clean tent to be sure
   that we have no conflicts with FDC work.
 - The cooling clamp assemblies for the preamp boards are in our possession.
   There are enough pieces for the full-scale prototype. Note that there
   are several different types of these assemblies to allow mating with the
   cooling ring loop. This was news to some of us, but at least now we
 - Bill will put together the order for the o-ring material for the
   full-scale prototype. We will also make sure that we have enough of
   the epoxies, syringes, and applicator tips that we nominally use.
 - We need to make sure that we have the support rods that go through the
   full-scale prototype on hand. DSC will follow up on this. Also we need
   to make sure that we have the appropriate pins for the construction jig.
 - We will use 5 existing 5-mm thick G10 rings for supporting our cathodes
   in a flat position after construction.
 - 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.
   Kim is ordering the LV cables.

Wire Frame Update

 - Status: IUCF is working to wind the fourth frame. They thought that
   there was a problem with the tensions of the wires on the table as
   they had sat for about 1.5 months. The table was cleaned off and then
   they found that there was a mistake in their calculations. They wound
   the table with the remaining sense wire and field wire and it was not
   enough for a full plane (84 sense wires instead of 96). They will use
   wire on both sides of the table and be able to wind the full plane. The
   wire soldering will be done by early Tuesday and measurements of position
   and tension will follow on Tuesday and Wednesday.
 - Mark S. will drive out to IUCF next Wednesday and pick up the frames
   on Thursday.
 - The systematic problems with wire placement on the first three frames
   have been linked to systematic problems with the Moire mask. IUCF did
   optical measurements and sent us a report. For the fourth plane, we will
   position the wires using a 30-cm length of the Moire mask that is in
   reasonable shape.
 - IUCF is now working on the budget for Phase 3 (production winding). This
   will be delivered to JLab by the end of May (the end of the 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.
 - Mark found that our the rigid-flex assembly solder clearance slots on
   the back of the fifth wire frame that we have (with the solder mask
   boards) had very noticeable non-uniformities in the depths of the slots.
   Some problem from machining. DSC asked Keith at IUCF to check the slots
   on the frames that he has. If the problems are there too, we will have
   to do something about this. Bill is aware of the problem and will think
   of a solution (after the Tagger review).
 - We are starting to consider moving up production winding to the end
   of next year. DSC and Eugene are now in discussions.
 - Eugene will look into the state of the agreement with Hampton University
   for FDC construction in their clean rooms. The loop on this needs to
   be closed soon.

Cathode Construction

 - 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.
     * 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. We are looking into purchasing the 
    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.
 - Additional space on the walls of EEL 126 has been set up for storage
   of our completed cathodes.
 - 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.

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 have scanned the flatness
   of our 5 micron Cu cathode and are going through the data now. We will
   also 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

 - 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.

Cosmic Ray Test Stand

 - We will be moving the FDC cosmic ray test stand from the Test Lab back
   to the EEL building early next week. Beni has come up with plans for the 
   room layout in EEL 126. The room has been prepared for the move.
 - 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).
   Bill and/or Brian will start to think about designing a system to rotate
   the prototype from vertical to horizontal.
 - 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.