Minutes 10-30-2007

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FDC Weekly Meeting

Date: October 30, 2007

Participants: Daniel, Roger, Bill, Kim, Chuck

Next Meeting: November 8, 2007

Scheduling Update

 - DSC is working on a detailed schedule for each phase of the FDC
   project that will take us through the construction of the full-scale
   FDC prototype.  The present plan is to complete the construction
   by the end of June 2008.
 - This schedule has been passed on to Elke for review as she is more
   aware of the current schedule constraints on the folks working on
   the project.  Once we iterate a couple of times on this, I will
   present this to the group so we can be clear on when the individual
   sub-projects need to be completed.
 - Once we are all in agreement on the schedule we will really have
   to take this seriously and do all we can to stay on target.  Note
   that the end of June timeline is not arbitrary.  We are working 
   toward this date to be ready for the CD-3 review.

Magnetic Field Tests

 - The test run officially ended on Monday at about noon as we had to
   clear out of the Hall B alcove in order for the Hall B folks to
   finish preparations for the upcoming run.
 - We ended up collecting long data sets in the final configuration of
   the chambers with the prototype filled with an argon/CO2 mixture
   of 40%-60% at 0T, 0.6T, and 1.2T.  We also took long B=0T and 1.2T
   data runs with the prototype filled with a 90%-10% argon/CO2 mixture.
 - Simon will continue data analysis when he returns from Hawaii.
 - DSC has removed all detectors and cables from the pair spectrometer
   area and coiled up all signal and power cables in preparation for
   our move back to the Test Lab.
 - One complication that came up is getting our electronics racks out
   of the area.  The downstream beampipe is in place and has been
   surveyed.  It will have to come out to allow crane access.  I have
   been in discussions with Doug Tilles and we will work this out.

Update on Progress

 - We had a preliminary meeting on finalizing the O.D. of the FDC
   support frames.  Is the final number 1200 mm or 1178 mm?  The design
   drawings are all 1178 mm, but the frame prototypes are all 1200 mm.
   A final decision will be made at a meeting that is scheduled for
   Monday November 5 at 8:30 a.m..  Unless there are real mitigating
   reasons for going back to 1200 mm, we will stay with 1178 mm.  Also
   there are preliminary discussions ongoing about inserting another
   detector for timing measurements inside the BCAL at some point in
   the future.
 - Brian will begin construction of the 3 composite wire frames for
   the test winds starting next Monday.  He will make one or two frames
   with low density Rohacell and one or two frames with medium density
   Rohacell.  We would like to be able to bring frames of each type for
   further study in the test winds.


 - Kim is now back full time and will return to the STB/HVTB designs.
   We will have a discussion about the timelines needed for completion
   of these boards and may have to work on negotiations with Kim's
   supervisor on getting more of her time so that we can meet our
 - DSC requested copies of all of the circuit boards from Kim so
   that Chris' group could make suggestions on quicker ways to change
   the O.D. of the annulus without using brute force approaches due
   to limitations of PCAD.  It sounds like some progress was made on
   this front.
 - Kim has indicated that even with an O.D. of 1178 mm, she believes
   that there is enough real estate on the boards to get all the traces
   on the board following our design rules for minimum spacing.  We
   still need to discuss if there is sufficient room for ground plane
 - We discussed the problems with the packaging of the dummy boards
   and also the problems with the edge designs that resulted in narrow
   corners that were easily broken off.  We will make changes in the
   final design to avoid these problems.  We will also be sure to
   specify how we want the final boards packaged and shipped.

Cathode Construction

 - DSC and Brian talked offline about the current ideas for the mounting
   and alignment of the 3-piece cathode system.  Brian will be making
   a composite cathode prototype shortly and will test his current ideas.
   We will then work to tweak the process so that we have a final
   procedure that can meet our specifications.

Wire Stringing

 - DSC has been in communication with the folks at IUCF regarding
   preparation of a budget for the FDC winding project.  A budget
   has been prepared and passed on to the budget folks at IU for
   review.  Even with their overhead rate (~35%) and a large
   manpower contingency for the test wind period, their budget will
   come in at or below $100k.
 - The IUCF folks also thing there is a reasonable chance that they
   could complete the test winds for us.  One issue is that the wire
   winding lab, which remains intact, has not been used for than
   10 years.  There will be some work involved in getting thing up
   and going again.
 - Brian has been in contact with Karen Kephart at FNAL about
   performing our test winds.  It looks like they could possibly
   wind just before Thanksgiving.  More news to come.

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 brief update on his continued work on designing
   an appropriate cooling system for the FDC preamps.  He stated that
   due to all of the connections between each daughter board card and
   the cooling ring, that the design will be quite complex.  He also
   stated doubt that our $15k budget will be enough.  However, a
   cooling system is also needed for the CDC daughter boards and maybe
   also for the SiPMs for the BCAL.  For now Bill will work to come
   with a workable design without initially worry about costs.
 - DSC asked Bill to bring some sketches/drawings of his initial
   design to our next meeting so that we can have a more concrete

Daughter Boards/Transition Boards

 - Fernando has posted a document on the GlueX portal (GlueX-doc-871)
   entitled "The GPC-01 GlueX Preamp Card - Preliminary Test Results".
   Folks should look this over and direct any feedback to Fernando.
 - Fernando will deliver pictures of the front and back of the daughter
   boards and interposer boards (boards to mate the daughter boards to
   the small-scale prototype).
 - DSC, Brian, and Simon will work to reassemble the FDC test station
   in the Test Lab.  We need to accomplish this within a couple of
   weeks so that we can have sufficient time to test the characteristics
   of the daughter boards and ASICS in order to provide feedback to
   Mitch Newcomer.  This feedback will be necessary to prepare for
   submission of the design for the next version of chips needed for
   the full-scale prototype and CDC tests.

Hall D Collaboration Meeting

 - Simon gave two talks at the Hall D meeting last week (and also one
   at the software workshop that preceded this meeting).  The first
   talk that Simon gave was a general update on R&D and software
   development.  The second talk was on the choice of technology for
   the FDC.  Simon did a great job in presenting our work.  The
   feedback that we received was that folks are no longer especially
   concerned on the material thickness issues in the active and
   inactive portions of the chambers.  The biggest issue that lingers
   is the impact of the magnetic field on the chamber performance
   (in terms of resolution).

Upcoming Meetings

 - Elke wants to have a meeting for the FDC system in December to
   review the FDC technology choice.  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 will meet with him next week to finalize
   the specifics of the studies that need to be performed.
    ** Remember that one of the reasons why the cathode strip chambers
       are supposed to be an advantage over standard drift chambers
       is that they should be able to improve the track finding
       efficiency in the multi-particle + background environment of
       GlueX.  This needs to be quantified and comparisons need to be
       made between cathode strips chambers and drift chamber through
       the Monte Carlo.
   ** David has stated that he believes all of the important questions
      can be addressed on the December time scale.
 - The next formal FDC review is slated for March 2008.  Elke is 
   working to get the same reviewers as the last review as we will have
   a strong focus (obviously) on how we have addressed the concerns of
   the review committee.

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.