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FDC Weekly Meeting

Date: June 26, 2008

Participants: Daniel, Simon, Kim, Roger, Mark, Micah, Eugene

Next Meeting: July 3, 2008 @ 1:30 p.m.

Cathode Planning

 - Roger has basically completed the cathode design drawings.  He has
   sent the design drawings to Fernando for blessing on the layout.
   Fernando is currently on vacation, but he may be able to bless the
   layout remotely.  After the meeting DSC spoke with Bill Crahen who
   has looked over the gas hole and through-hole locations and given
   his final blessing on these.  We still need to include the cathode
   layout into the CAD model and this will be done at some point in
   the near future (probably after the CD-3 deadlines).
 - The plan is to procure the cathode boards for the full-scale
   prototype in a two-stage process.  We will first procure two full
   sets of 2 micron Cu boards and two full sets of 5 micron Cu boards.
   We received a quote this week from Allflex on the first order.  It
   has come in at $3.2k per set with a $2k tooling charge.  After we
   bless these boards, we will hopefully then move to order an
   additional 4 sets of each board type.
 - Roger has all other information necessary to complete the PR and
   hopefully this will converge very shortly so the order can go
 - DSC asked Roger to meet with Fernando upon his return next week
   to lay out the plans for electrical checks on the delivered
   cathodes.  After we finalize the plan, we will order the test
   equipment needed if we do not already have it.
 - Roger is working with the Allflex representative to find whatever
   information is available from Nippon on the raw material specifications.
 - Additional solder tests of the rigid-flex assembly to the cathode board 
   mock up will proceed after Roger gets the hot air pencil from Fernando.
   This work will wait until the cathode board PR is completed and Roger
   has time in his schedule.
 - Due to the height of the solder connection between the cathode board 
   and the rigid flex assembly, we will have to revisit the design from 
   the standpoint of adding clearance pockets on the surfaces that mate 
   up against this solder region.  Chuck is responsible for looking into
   this and letting us know.
 - Brian will modify his Lucite box design for storage of the completed
   cathode planes.  The cathode planes can stack upon one another
   (unlike the strung wire frames).  He will make some minor modifications
   to the existing box drawings and prepare the PR.  This work will
   proceed in July when Brian gets back to town.
 - Bill found a precision straight edge 1.5 m long for $750.  We can
   decide in the upcoming weeks if this is appropriate to purchase to
   cut our cathode boards to width.

Full-Scale Prototype

 - The order for the 5 ft x 5 ft granite table has now gone out.  The 
   table should arrive in about 2 weeks of time.
 - The work to modify the existing aluminum tooling plate and make
   a second are in the queue in the JLab machine shop.  Simon found
   out from Casey that due to a new high priority FEL job, our work
   is not scheduled to begin until August.  DSC has contacted Elke
   to find out how we can get our priority for this work increased.
 - Brian found that the power cord for the clean tent did not reach any
   of the recepticles in the clean room.  He made a request to plant
   services to have an outlet installed.  No update on this work.
 - Brian and Bill will work to update our wire frame construction sequence
   document.  Brian will provide a first draft to Bill who will work to
   polish it up.  We would like to provide this to Casey so his group
   (and of course ours) can full understand the procedures.  This work has
   not yet gotten underway.

Cathode Prototyping

 - No work done on cathode prototyping this week.  Still need to pursue
   techniques to tension cathodes to a particular (pre-determined) point.
   We still need to pursue mechanical solutions (fixed weights to define
   the tension).  More work when Brian returns from vacation.
 - We will try to develop a cathode tension measuring system using our 
   laser measurement head.  The procedure will be to direct a puff of 
   air at the center of the cathode and measure the amplitude fluctuation 
   vs. time through the laser measurement system.  Fitting this amplitude  
   distribution will give us (hopefully) the fundamental frequency that 
   we should be able to convert into the membrane tension.  More to come.

Test Frame Wire Winding

 - We had a teleconference with IUCF at noon today to finalize the
   planning on the continuation of phase 1.  A budget of $10k was
   agreed on by all parties and we will move ahead with finalizing
   the paperwork early next week.  We then will want to ship two
   additional wire frames to IUCF for this work.  In this regard, DSC
   will provide a brief statement of work for Elke to review this
   week and we will then send it on to the JLab contracts folks.
 - We have one frame ready to go to IUCF for the continuation of Phase 1.
   A second wire frame is being worked on in the JLab shop to add the
   through-holes to the frame.  As mentioned above, our delivery date
   has slipped considerably in the JLab queue due to other work.  DSC
   has contacted Elke to get the work on the second frame done ASAP.
   More information to come.
 - DSC is working with Steve Christo to prepare a wire specification
   document for the tungsten and CuBe wires leading up to procurement.
   Steve is preparing a document for the Hall B chambers and we will
   most likely adopt this document for Hall D.  DSC reviewed the
   existing Hall B documents to give folks a flavor of how these
   documents have been prepared in the past.  We need to make decisions
   on what is required for the FDCs.

Stack Assembly Procedures

 - DSC, Brian, Tim, and Bill will work to finalize the stack assembly
   construction document that has been prepared.  This document should
   be in place before we get too far in the construction process.

Cathode Flatness Measurements

 - Micah is working on upgrading the system readout electronics.  He
   has prepared a time line for the system work so that we can
   have a rough idea how he plans to make progress and complete the
   system upgrade and complete the required suite of measurements
   before the end of the summer when he disappears.  DSC will go over
   the schedule and give feedback.
 - Micah will also put together a list of things that need to be
   purchased so that we can start the procurement process as soon as
   we can.  This is nearly ready.  When the plan is fleshed out, DSC
   will meet with David and Micah to go over things.
 - Micah presented some laser scans done on a frame that Denny had
   already done some measurements on.  In short, the features seen
   in Denny's measurements were not reproduced in Micah's data.  This
   needs to be investigated and we suggested a number of simple checks
   that could be done as basic sanity checks that the system is
   providing accurate data.  It was also the case that Micah's data
   showed a bulge that was twice as big as what Denny found.

Cooling System Tests

 - Fernando is nearly ready to perform the cooling system measurements.  
   Bill has ordered a flow control valve that will arrive shortly and be 
   installed in the system.

Gas System Design

 - Vladislav (Slava) Razmyslovich is working on a preliminary layout
   of the gas handling system for the CDC and FDC in preparation for
   the upcoming systems review.  We will sit down with him in a
   specialized meeting to review the design concepts when we get a chance.

STB/HVTB Discussion

 - Kim needs to provide an instructional writeup for the Phase 1 and
   Phase 2 wire frame PCB component attachment.  This is on her to-do
   list, but is not a high priority for now.

Cathode Board Discussion

 - Roger needs to prepare a document for QA/stuffing/cleaning for the
   cathode boards and a similar document for the cathode daughter
   boards and ground boards.

Small-Scale Prototype

 - Simon has continued his data acquisition with the small-scale
   prototype and has taken new 55-Fe source data and cosmic data
   with the new grounding configuration.  He in principle has 
   everything that he needs to complete a first attempt at extracting
   numbers for the cathode and anode dynamic ranges.  However, there
   are a number of assumptions that we will have to make along the
   way.  Certainly these assumptions will have to be advertised and
   discussed.  Simon will aim to make a presentation to the Hall D
   group next Wednesday as well as to update his GlueX note on this
   topic.  This work is posted as GlueX-doc-1070.


 - DSC has collected all of the available FDC subsystem design drawings
   and placed them on the FDC website.  The URL is:
   http://www.jlab.org/Hall-D/detector/fdc/drawings.html.  Folks should
   go through the drawings and let DSC know what drawings and/or categories
   are missing for a complete design set.
 - Also folks should send DSC the latest design drawings where there
   have been changes to keep this web site up-to-date through the
   review season.

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.