Minutes 10-4-2006

FDC Weekly Meeting

Date: October 4, 2006

Participants: Daniel, Brian, Simon

Next Meeting: Wednesday, October 18, 2006 @ 1:30 p.m.

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Full-Scale Tensioning System

 - Brian reported that the materials for the full-scale cathode
   tensioning system have arrived.  He will ask the shop to construct
   the device once we are ready.
 - Brian asked that we verify that the largest possible diameter of
   the active cathode area is 1.2 m.  We verified this from Ravi's
   latest mechanical drawing.

Wire Plane Circuit Board

 - The wire circuit board will consist of circuit board tiles laminated
   on a g10 backing.  Brian (and Chris Cuevas) believe that this will
   give us the most flexibility in choosing a vendor and will not  
   give us any problems in precision as dowel pins will be used to
   define the relative positioning.
 - Brian has continued to work on the mechanical design and the wire
   plane design.
 - The wire plane circuit board will be divided into a signal side
   and a HV side.
 - The current design consists of a frame with a 3 in (approx)
   annulus ==> 103 sense wires, 104 field wires.

Rohacell Order

   The Rohacell order finally is signed and out the door.

Mechanical Drawings

   Brian believes his mechanical drawings are nearly far enough along
   to give to the Electronics Group for design.  DSC believes that
   we should not rush this forward.  We need to work on such areas
   as the gas distribution design for the chambers to reduce the
   number of design iterations.

Cooling System

   We need to think about the on-chamber cooling system for the
   electronics.

Mechanical Design

   We discussed how to attach the FDC layers within a package.
   Currently we have ~48 ``threaded rods".  This is necessary to
   compress the o-rings.  DSC asked Brian to consider a ``quick"
   disconnect system to enable access to the chamber faster.  Brian
   suggested a cam-type securing bolt that could be easily released.

Monte Carlo Update

   Simon reported that HDFast is really broken.  DSC asked Simon if
   he could use an old version.  Simon will look into this.

Copper Thickness

   It is not clear what copper thickness we have on our flex boards
   for the cathodes.  1/4 oz vs. 1/2 oz?  Brian and Simon will look
   into this (check the order form that Randy Wojcik put together).

Schedule

   Meet in two weeks after the GlueX Collaboration meeting.

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