Minutes 11-5-2007
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FDC Special Meeting on Frame Size
Date: November 5, 2007
Participants: Daniel, Brian, Simon, Elke, Bill, Kim, Chris, Tim
Next Meeting: November 8, 2007
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.