Minutes 11-5-2007

FDC Special Meeting on Frame Size

Date: November 5, 2007

Participants: Daniel, Brian, Simon, Elke, Bill, Kim, Chris, Tim

Next Meeting: November 8, 2007

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FDC Frame Size

 - A special meeting was held today to finalize the decision on the
   O.D. of the FDC wire and cathode frames.  Two different values have
   been floating around, namely 1178 mm and 1200 mm.
 - The 1200 mm O.D. was based on the original design that left a
   5-mm clearance around the perimeter of the FDC for cables and 
   support hardware.  This number was changed some time ago (possibly
   as long ago as December 2006) in the CAD model to allow room for
   the signal cable connectors.
 - Brian and Tim reported that there are no issues with mechanical
   strength of the smaller frame O.D..  Even though Brian has made
   all of his frame prototype at an O.D. of 1200 mm, Tim's calculations
   were based on the 1178 mm design.
 - Kim reported that with the 4-layer STB board, there are no issues 
   with real estate for the traces and ground planes on the circuit
   boards.
 - Elke had indicated that there were some thoughts about a future
   upgrade to install some sort of detector outside of the FDC at the
   downstream end to improve hermeticity between the BCAL and FCAL.
   Given that with the 1178 mm design there is only between 1 and 2
   inches of clearance outside of the FDC, that this should not drive
   any of the FDC design.  In fact, with the changes in the placement
   of the FDC packages, this point may be moot anyway.
 - The bottom line: The FDC group has adopted a final frame size for
   the FDC system that has an I.D. of 970 mm and an O.D. of 1178 mm.
 - Brian will begin construction today of the composite wire frames that
   include the dummy boards.  These frames will be used in the upcoming
   wire stringing tests that will take place in November of December
   of this year.

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