Minutes 8-22-2007

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FDC Weekly Meeting

Date: August 22, 2007

Participants: Daniel, Simon, Chuck, Tim, Kim, Roger, Fernando

Next Meeting: September 5, 2007

Composite Wire Frame

 - Brian has completed making the composite wire frame.  We are presently
   awaiting the machining of the o-ring groove and the through-holes.
   This is being handled by the JLab machine shop and they indicated that
   this work will be completed before the end of August.  Stress testing
   of this frame will then follow.

Composite Cathode

 - No new work since last week.  This is on Brian's to-do list.  All
   pieces (G10 skins and Rohacell core) are in our possession.  Brian
   will use the existing 3 piece dummy cathodes.  The plan is to make
   a complete full-scale cathode.


 - Roger sent a Gerber file of the two piece STB and HVTB design (just
   showing outlines of the overlapping boards) to Sierra.  They indicated
   that the size of these boards is not an issue.  So we have a final
   design that the STBs and HVTBs will be a two piece design.
 - Kim is back on the FDC project after several weeks away on other
   work.  She will begin laying out the final design for the full-scale
   prototype.  Work will begin first on the STB and then the HVTB will
   follow.  She has no questions at the current time and should have an
   initial layout by next week.
 - Roger and Kim will prepare designs for "dummy" STB and HVTB circuit
   boards in the next week.  These circuit boards should contain the
   solder pads and the sighting fiducials.  They will also prepare the
   "junction" boards that go between the STB and HVTB.  These boards
   are needed for the test winds that are scheduled at FNAL later this

Magnetic Field Tests

 - Preparations for the magnetic field test with the small-scale prototype
   continue.  We have installed the lower set of 4 MWDCs that make up half
   of our cosmic ray telescope.  The upper set of 4 MWDCs will be installed
   after a light above the magnet is removed on Thursday.  We will then
   installed the small-scale prototype chamber inside the magnet.  We will
   then work to optimize the grounding configuration of the system and then
   perform alignment of the chambers as best we can in this rather confined
   space.  Gas is flowing through the installed chambers and all cables have 
   been strung.  We should be ready on Monday of next week to begin check out 
   of the data acquisition system.

Daughter/Transition Boards

 - The FDC daughter boards should be in our hands within about a week.
   Fernando will then mount the ASICs and perform some tests.  We will
   need to be ready to install these boards on the small-scale prototype
   in October.
 - In order to be compatible with the small-scale prototype, we need
   a transition board to go between the chamber and the daughter board.
   Fernando is beginning work on this board and it should be ready in
   about 1 week.
 - The daughter boards will be compatible with the gain/shaper modules
   that Gerard provided.  To read out the entire chamber, we will need
   3 more cathode boards.  Fernando will contact Gerard about making more
   of these boards.  Also Fernando will talk to Gerard about what we
   should measure with the ASICs on the small-scale prototype.


 - We need to place our orders for procurement for this fiscal year
   by September 4.  This includes the shop charges for the wire frame, 
   dummy circuit boards for the wire frames, a spool each of field and 
   sense wire, additional G10 skins, and shipping funds to send a sample 
   of the readout cable to Gerard.
 - Brian was not in attendance at today's meeting so Simon will contact
   him this week to prepare the PRs for the procurements.  The shop
   charges should be incurred this month according to what we know.  The
   cable shipment to Gerard is awaiting the arrival of our cable from

Small-Scale Prototype

 - No work done on mounting the +/-75 deg cathodes yet.  This is on
   Brian's to-do list.

Cathode Rough Out

 - This week Roger will begin work on laying out a rough design for
   a cathode board with a hole in it about the beam.  Actually there
   will be no physical hole, we will just not have copper there.  We
   plan on reading out strips above and below the hole.  While we plan
   on having a package-dependent deadened region on the sense wires,
   we would like to have a single cathode design.  We must keep in mind
   that the readout is quantized into 24-channels.  The hole should
   be 3 cm in radius.  Once Roger has completed this layout, he will
   circulate a file for us to consider and discuss.

Cathode Board Readout

 - Our current design plans call for a flex-type cable to be epoxied or
   soldered to the face of the cathode plane and then to route through
   the cathode frame (through a cut out) to the daughter board connector
   on the back side.  We had a general discussion on possibilities and
   options for this connection.  After Roger completes the work on the
   cathode rough out, he will begin work on a design for the connections.
   We would like to be able to build a prototype of this connection
   scheme and have this done by the end of this year.

DOE Report

 - Simon and DSC will update the TDR prepared for the chamber review in
   March to reflect the current FDC design.  We will then prepare a few
   page summary as the deliverable to DOE.  This report is due at the
   end of September.

Work List

 - The FDC short-term work list has been posted on the FDC web site
   (see http://www.jlab.org/Hall-D/detector/fdc/).  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.