Minutes 12-20-2006

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FDC Weekly Meeting

Date: December 20, 2006

Participants: Daniel, Brian, Tim, Chuck, Roger, Fernando, Elke, Kim

Next Meeting: Wednesday, January 3, 2007 @ 1:30 p.m. (tentative)

Chamber Frames

 - Brian brought one each of the blank G10 and CH2 frames that 
   have been constructed for the cathode mechanical construction
   effort.  We studied the floppiness and the basic properties.
 - We discussed an option to use carbon fiber frames for the 
   spacers that do not have o-rings (as this is hard to machine).
   This choice will have roughly 1/2 the mass for a given thickness
   compared to G10, but costs a factor of several more.  Brian is
   working to get a realistic quote for these rings.
 - We are still waiting for feedback from Zisis and David regarding
   the allowable material thickness in the annulus before making a
   final design decision regarding material choices.
 - The current annulus I.D. is 970 mm and the O.D. is 1198 mm.  These
   number are still in flux somewhat.  At the current time Roger and
   Kim have defined the layout of the STB board geometries.  The
   HVTB geometries will be the same as the STBs.

Design Work

 - Fernando has been working on the preamp daughter boards and work
   is still ongoing.  He is working to make the boards as small as
   possible.  Once this design is finalized and the position for
   the connector is finalized, Roger and Kim will work to layout the
   traces and final component locations.  
 - The current design of the radial extent of the daughter boards is
   66 mm.
 - Based on our use of 4-layer boards for the wire plane, Roger is
   confident that we should have enough room for everything to
   safely fit on the annulus in its current size.
 - Fernando brought a sample of the daughter board connector that
   he is planning on using.  This is a surface-mount connector with
   plastic feet that go into the board to give it stability.  The
   thickness of the connector is 5.44 mm, which was actually the
   thinnest that he could find.  It turns out that this connector
   thickness dictated the half-gap in the chambers!

FDC Budget

 - The FDC budget for CD-2 has been completed and was turned in for
   internal (collaboration) review.  Daniel will send it around for
   folks to comment on.  Everyone should look over the sections that
   they are responsible for to make sure that things are O.K..
 - The budget item for winding the wire planes has not been finalized.
   We are in negotiations with Karen Kephart at FNAL where we plan
   to have the planes wound.
 - Now that we know roughly where the surface-mount components will
   go, Brian will talk to Karen about possibility of winding planes
   after the components have been soldered on.

Cathode Sandwiches

 - Brian is working to make sure that all of the hardware and materials
   needed to begin construction of a cathode-sandwich mechanical
   mockup are in-hand (or on order) before the end of the year shut down.
 - We have the G10 and CH2 frames in our possession, as well as the
   Rohacell.  The kapton will come from Steve Christo and the aluminized
   mylar is on order.  We will be working in the machine shop.
 - Brian and Daniel will meet in early January upon Brian's return to
   make plans for cathode construction. 
 - Brian will touch base with the survey crew here at the lab about
   making the flatness measurements of our cathodes.  They had indicated
   already that they might be able to rent a suitable system or even
   come up with funds to purchase one.  We may also have the option of
   contracting this out locally.  We would like to have measurement
   feedback on our constructed cathodes before the end of January.

Minutes prepared by Daniel. Send any comments or corrections along.