Minutes 11-15-2007

FDC Weekly Meeting

Date: November 15, 2007

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

Next Meeting: November 29, 2007

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Manpower Update

 - Everyone matrixed into our working on the FDC hardware aspects
   excluding Tim and Chuck have been provided with a detailed list
   of tasks and an associated time line for work until the end of
   June 2008.  This is our internal deadline for completion of the
   construction of the full-scale FDC prototype.
 - DSC would like everyone in the group who has not already talked
   to him to schedule a brief meeting with him to go over the 
   schedule to be sure we have an agreement on the list of tasks
   and the schedule.  Please do this in the next few working days.

Composite Wire Frames

 - The machine shop has nearly completed construction of the wire
   frame construction/alignment jig (which will ultimately become
   our package construction jig).  This should be ready by the end
   of this week.
 - The construction of the 3 composite wire frames with the medium
   density Rohacell core will commence on Monday.  The shipment
   containing our low density Rohacell core pieces is set to arrive
   at JLab next week.  Construction on the 2 composite frames with
   this core then will proceed.
 - We discussed the issue of the possible "slop" in the positioning
   of the frames on the alignment fixture due to the use of plastic
   pins.  A number of alternatives were discussed and we decided for
   now to replace 3 of our 24 pins with rigid steel "master" pins to
   ensure the alignment of the package stack layer to layer.
 - We discussed how to epoxy the dummy circuit boards together.  DSC
   is in favor of painting epoxy along the full overlap region to
   give the strongest bond.  Brian's original idea was to use a
   quick drying epoxy with simple tacks of epoxy along the joint.
   There was consensus that we want epoxy covering the full overlap
   region.
 - The detailed design of the supporting strongback has not advanced
   as of yet, but Brian has a pretty clear picture of what this will
   look like and the detailed design layout and associated drawings
   will take him no more than an afternoon.  This work will take
   place after we make more progress in the construction of the
   composite wire frames.
 - Kim reported that one of the sets of fiducial sights on the dummy
   boards is not aligned with respect to the wires.  These sights
   should be removed before winding to avoid confusion.
 - The order for our first 8-slot storage box is due into JLab next
   week.

STB/HVTB Design

 - Weekly design meetings have been set up with Kim, Fernando, and 
   DSC to go over the PCB design and address questions as they come
   up and to give feedback on the layout.  Our first meeting was
   yesterday and there was a lot of good discussion of details that
   we were able to hash out and finalize.
 - The STB board design should essentially be finalized this month
   and then work on the layout of the simpler HVTB will commence.
 - Kim brought along drawings of the current STB layout and discussed
   recent progress and what her plans were over the next week or so.
   Our next design meeting will be held next Tuesday before the break.
 - We discussed briefly how we will make the HV connections to the
   HVTBs.  The current idea is that wire pigtails will be soldered
   to the HVTB and end in a Reynolds-type low-profile connector.  These
   connectors would be attached to a distribution board on the downstream
   face of each package where the connections to the mother cables
   would be made.  Fernando suggested that we have the mother cable
   connect directly to the distribution panel with a single connector
   and then have connections to the individual pigtails at that point.
   We need to better understand what the HV connection options are
   and choose a connection scheme that is both robust and minimizes
   materials.  We will return to consider this design in more detail
   after the holiday break.

Wire Stringing

 - DSC has talked to the folks at IUCF.  The budget that was prepared
   by the wire chamber lab has passed across the desk of the lab
   director and is now in the hands of IU procurement.  We expect
   to get the budget shortly.
 - The current thinking is that the wire winding project will be
   opened up for bid.  In preparation for this, DSC has prepared a
   detailed statement of work and it is on Elke's desk for review
   at the current time.  When this is finalized, we will start
   discussions with the JLab procurement office.  The time line for
   all of the paperwork is unclear, and it seems hard to believe that
   anything can happen before the end of the year.  However, we will
   proceed as quickly as the system will allow us.
 - If we string at IUCF, we will have to construct a support system
   for the chamber frames to position them vertically for the wire
   measurement system.  We will work on this design only after it
   is known where the work will take place.

Magnetic Field Tests

 - Not much has happened on analyzing the data over the past week as
   Simon has been working on setting up the Test Lab and working on
   the Monte Carlo.  Details will be reported when there is something
   to show.

Cathode Board Readout

 - Roger showed a drawing of his planned design for making the connection
   between the cathode board and the daughter board connector.  He has
   given his design drawings to an outside outfit called Innovative
   Circuits, Inc.  They are reviewing the design.  Once we process their
   feedback, we will work to order parts for a mechanical prototype to
   study the design.

Cooling Scheme

 - Bill was at CAD training this week, so there was no update on the
   design of the cooling system.  DSC and Fernando will meet with Bill
   on Monday to have a discussion specifically on the cooling system.
 - Fernando will work to make some thermal images of the loaded
   daughter board to provide input to Bill's design.  We also need to
   continue to evaluate the design from the standpoint of minimizing
   material while designing a system that can handle the expected heat
   load.

Other Work

 - Simon and Denny are working to restore our cosmic ray test stand
   in the Test Lab.  They might even be able to start an acquisition
   run to check things out by tomorrow.  Fernando is expecting to give
   us loaded daughter boards and interposer boards before the break
   next week.  Fernando will talk to Joe about making cables for the
   tests so that they are ready when we are.
 - The second FDC Monte Carlo progress meeting took place just after
   the FDC meeting.  Mark gave a talk on the inefficiencies seen
   within the current helix fitting algorithm.  We discussed possible
   sources of the problem.  Dave went over progress on developing a
   track finding code, first for single charged particles, and then
   for charged particles in a realistic background, and then also
   for multiple real tracks.  The current work is ongoing for a
   beam-target luminosity of 102 photons/sec.  He will work
   to get things working here before increasing the photon flux by
   an order of magnitude.

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.