Minutes 9-26-2007

FDC Weekly Meeting

Date: September 26, 2007

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

Next Meeting: October 4, 2007

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Composite Wire Frame

 - Brian is slowly getting the items that he ordered for the test.
   He now has the wire and is awaiting the tensioning scale.  He
   expects to have everything in his hands this week and then will
   set up the stress test on our composite wire frame.  Tim will of
   course be present for all of the fun and to be sure that our tests
   are being done in such a manner as to compare against his
   calculations.
 - For the construction of the 3 frames for the wire stringing tests,
   we have the Rohacell in hand.  The order for the G10 rings has just
   gone out and delivery is expected on October 10.  I also believe
   that the order for the sense and field wire has gone out, but the
   delivery date needs to be confirmed.
 - Brian estimated that he will need less than a week to complete
   construction of the 3 composite wire frames for the test wind.  The 
   JLab machine shop has been contacted and they will handle the quick
   turn around time for the frame construction.

Composite Cathode

 - No work done yet.  Brian will get to this soon.
 - We discussed a plan to butt the neighboring cathode pieces up against
   each other and to seal the joint with kapton tape.  This would
   eliminate the overlap that was used in the last prototype.

STB/HVTB Design

 - Dummy boards for FNAL test wind have been ordered and we expect
   delivery on October 10.
 - Kim has not started design of the real STBs and HVTBs, but plans on
   having something to show us at our next meeting.

Magnetic Field Tests

 - The magnetic has been energized for a week now and we have taken some
   data at 1.2 T.  Simon gave a report at the morning Hall D meeting and
   his presentation is posted on the Hall D wiki.
 - He has managed to perform crude calibrations of the time to distance
   relation for the external chambers as well as the prototype.  He
   has also done a preliminary gain calibration for the cathodes.
 - We have some noise issues in the external chambers that are causing
   us to run at a higher discriminator threshold than we need to obtain
   full chamber efficiency.  We tracked this down today to the use of
   unshielded readout and power cables.  We are in the process of ordering
   shielded cables and will get them into the setup as soon as we can.
 - We will have a meeting tomorrow afternoon with Elke to go over the
   issues with the setup and the current state of affairs of this test
   to be sure that we are on track.

Small-Scale Prototype

 - Brian has not gotten to the mounting of the +/-75 deg cathode
   boards.  He has everything he needs to do this work, but has not
   had time.  He will get to this soon.

Cathode Rough Out

 - We worked through the issues with the cathode board size and the
   number of strips with Roger.  The board should have strips with
   4-mm width and a 1-mm gap.  The total number of strips across the
   active area should be 192 + 24.  This amounts to 9 24-pin connectors
   for the readout.  This also accounts for the beam hole in the center
   of the boards.
 - Chuck will work on defining the size of the 3 individual cathode
   boards that make up a single cathode plane.  The maximum size is
   19.5-in wide.  We need to define the placement of the daughter board
   connectors.

Cathode Board Readout

 - Roger has started this work by contacting various vendors.  His plan
   is to make several physical prototypes of the design for feedback and
   optimization.  We decided at our last meeting to remove the gap
   between neighboring cathode boards.  This will be done by burying the
   daughter board connectors inside the cathode frame.  We plan on using
   a flex-type cable that will run through the board to connect the
   cathode to the daughter board connector.

DOE Report

 - The FDC report on FY07 R&D has been posted as GlueX-doc-861 and it
   was turned over to Elke last week.  She will put it into the final
   form needed for DOE.

FNAL Budget

 - We had a meeting today to go over the FNAL budget and to discuss what
   our options for winding the chambers are.  We agreed to revisit what
   labs have the capability to wind chambers of this size.  We will
   contact BNL, DESY, SLAC, and IUCF.  
 - We are still planning on winding the test planes at the beginning
   of November at FNAL.  However, details are still to be worked out.

Daughter Boards/Transition Boards

 - Fernando showed us the prototype daughter boards and transition
   boards for the small-scale prototype.  He went over the features
   of these boards and the basic component layout.
 - Fernando will take pictures of both boards and circulate them.
 - The 4 cathode boards and 1 anode board for the small-scale prototype
   should be ready for us to install in less than a month or so.

Cable Order

 - The order for the readout cable should be in our hands any day now.
   The connectors will not be shipped for another month or so.  We will
   still proceed with tests once the cable arrives.  Joe Beaufait will
   be handling this.  A sample of the cable will be shipped to Gerard
   Visser at IUCF.

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.