Minutes 11-8-2007

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FDC Weekly Meeting

Date: November 8, 2007

Participants: Daniel, Brian, Simon, Roger, Bill, Kim, Chuck

Next Meeting: November 15, 2007

Manpower Update

 - DSC reviewed (briefly) the manpower time-lines and work plans that
   he has prepared.  He and Simon will meet with Elke this afternoon
   to go over the plans and then DSC will talk to the individuals
   matrixed into the project.
 - Several points of good news regarding manpower. 1). Kim will be
   changing over to 95% Hall D starting next week (she has been at
   50%).  2). Elke has arranged for 50% of a Hall B technician to
   work on the FDC project starting soon (details to come).  The
   plan is to have this person work to alleviate pressures on both
   Simon and Brian.

Magnetic Field Tests

 - Simon has been working on the preliminary calibrations of the
   detectors for the runs taken.  Simon and DSC will have separate
   analysis meetings to review the work and to discuss problems and
   issues.  The group will be kept informed of progress as we go

Composite Wire Frames

 - Brian has begun work to construct the composite wire frames for
   the test stringing that is coming up this year.  We plan on
   constructing 3 composite wire frames using the dummy boards with
   a medium density Rohacell insert and 2 composite wire frames with
   the dummy boards and a low density Rohacell insert.  3 of the 5
   planes will be sent off for the test winds.  At least one of these
   will include the low density Rohacell filler.
 - To progress on the construction, we need to construct an alignment
   jig to ensure that all of the circuit boards and filler boards are
   properly aligned during the lamination and attachment procedure.
   The current plan is to use the big aluminum tooling plate that Brian
   is using as the weight.  The machine shop will machine in places
   to attach dowel pins over which the circuit boards can be placed
   during lamination.  This same alignment jig will also serve as the
   tooling used during FDC stack construction.  The dowel pins that
   will be used will have a slight taper at the end to allow easier
   construction.  Brian will circulate drawings of his plan.  He
   will be in contact with the machine shop to get this work completed
   with a week or two.
 - We discussed the plans for construction of the strong-back that will
   be used to keep the wire plane flat during the process of attaching
   the wires.  This same strong-back, or a separate piece of similar
   design, will also be used during FDC stack construction to ensure
   that the wire frame will be easy to install on the FDC stack during
   construction.  Brian has a rough design laid out.  He will finalize
   the design and circulate for comments.


 - We discussed the plans for the holes on the circuit boards.  The
   current plan is to include slightly undersized holes of 3/16-in
   diameter where the through-rods will go.  These undersized holes
   have been chosen to be of a size that matches with stock dowel
   pins.  Once the wire frame has been constructed, we will complete
   the drilling of the through holes through the circuit boards, the
   Rohacell, and the solid G10 ring.
 - We also discuss some minor changes to the design of the geometry
   of the STB and HVTB boards.  One thing that we learned from the
   design of the dummy boards is that we want to eliminate the long
   skinny sections of the PCB board.  The second is that we want a
   much tighter tolerance on the overlap regions between boards so
   that they but nicely up against each other.  Both of these issues
   are relatively minor changes to the design that involve minimal
   work to update.
 - Kim is working with several other folks to improve the efficiency
   of laying out the boards.  Due to limitations of the CAD program
   her group is using, it is not easy to draw certain shapes at certain
   scales.  She has worked to find a work around to this problem that
   will speed things up.

Wire Stringing

 - Discussions continue regarding where the wire winding for the FDC
   project will occur.  DSC has been in contact with the procurement
   folks at JLab to get them more involved in the organization and
   contacts.  IUCF is now preparing a budget estimate that they should
   deliver to us soon.
 - In discussions with Elke, we have come up with a plan to write a
   statement of work for the project complete with all specifications
   and time lines, and then open up the project for bids.  As there
   are only two competitors in this race (FNAL and IUCF), I think that
   we would have the best chance to get the best price, i.e. one that
   can fit within the FDC budget.
 - DSC will contact the folks at FNAL to bring them up to speed on
   where JLab is in the process.
 - Brian has completed the design of the wire frame transport/storage
   container and the paperwork has been signed.  We expect delivery
   in about 2 weeks.

Cathode Board Readout

 - Roger has continued to flesh out his design for making the
   connections between the cathode boards and the daughter board
   connector.  He is nearly ready to order parts for a mechanical

Cooling Scheme

 - Bill presented a CAD model of what he foresees is needed for the
   FDC on-chamber cooling hardware.  It involves tubing lines, one
   for each package, that connect to a manifold located on each package.
   Lines from this manifold that run in loops up between the different
   layers that come into contact with the bracket on the daughter boards.  
   This design introduces some new material into the frame region.  
   Currently, his model includes a total of 2.5 kg of aluminum (brackets
   that thermally connect the cooling lines to the daughter boards),
   18 kg of copper lines (which could possibly be replaced with aluminum),
   and about 1.4 kg of coolant.  The options are water and fluorinert.
     > From wikipedia: It is an electrically insulating, inert 
       perfluorocarbon fluid which is used in various cooling applications 
       but is mainly for cooling electronics.
   The fluorinert would certainly be less harmful to our electronics 
   compared to water in case of a coolant leak.
 - As a next step, Bill needs to meet with Fernando to go over the
   detailed specs of the cooling system from the standpoint of the
   ASICS so we can finalize the cooling capacity needed.  Bill also
   wants to construct a prototype test system to do some cooling
   measurements in an environment similar to that the daughter boards
   will live in.

FDC Mini-Review

 - Elke wants to have a meeting for the FDC system in December or
   possibly January to review the FDC technology choice.  This meeting
   would most likely be with internal JLab experts.  In order to be 
   prepared for this review, we still have several important Monte Carlo 
   studies that must be performed.  This will be a priority for David 
   Lawrence over the next month.  We had a meeting with David, Mark, and
   Elke this week to go over the list of questions that need to be
   answer, a rough time line, and we identified the manpower to work
   on the various aspects of these studies.  We will keep folks updated
   on progress.
 - This meeting and the results that come out of it are designed to
   help us better prepare for the formal FDC chamber review in March.

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.