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FDC Weekly Meeting

Date: September 4, 2008

Participants: Daniel, Simon, Fernando, Mark, Kim, Roger, Chuck, Eugene, Bill, Micah, Herun, Jim, Beni

Next Meeting: September 11, 2008 @ 1:30 p.m.

Full-Scale Prototype Updates

 - Clean Room:
    * Brian is working to put our clean room/tent together.  He has gathered
      sticky mats, gowns, hats, gloves, shoe covers, cleaning equipment, 
      trash cans, etc..  He has ordered a few things such as sticky rollers 
      to clean the area that will arrive soon.  He will get a bench and a 
      storage closet soon.  
    * Brian and I are now finalizing a procedure for entering into and 
      leaving the clean space that we will all have to follow.  After this 
      procedure is finalized, we will all meet at the clean tent have a 
      walkthrough of everything.  As of now, we will be following full clean 
      room procedures in the tent.
    * Someone unplugged the clean tent and we do not know who.  Simon
      will post signs on the clean tent for contact information should
      there be any questions.
    * Alexandre Deur's group needs 220 V power and has asked if they
      could borrow our outlet.  There is another outlet on the side of
      the clean room by the viewing window that can be used potentially.
      DSC will talk about this with Brian upon his return from vacation
      next week.
 - Procurements:
    * Roger is still working to finish the design work for the cathode
      rigid-flex assemblies.  He still has several days of design work to 
      do and hopes to put the order together in the next several weeks.  We
      will be ordering enough of these assemblies to outfit the entire
      full-scale prototype.  The final number (roughly 70) has yet to be
    * Kim has completed the PR for the signal cable connectors and for the
      manufacture of the LV cables.  No word yet as to delivery date.
    * Elke asked us to prepare a spreadsheet listing all expenditures for the
      full-scale prototype.  Kim has started to prepare this including all
      of her procurements (including those through Fernando) and those of
      Bill.  She still needs input from Brian, Roger, Lorelei, Simon, and
      anyone else who has order parts n' pieces.  We will post a draft of
      this spreadsheet in an accessible place shortly.
    * Brian is working on the procurement of the sense and field wires
      for the full-scale prototype.  DSC has prepared two documents for our 
      wires: Wire Specifications Document and Wire Testing Document.  
      These documents have been passed on to the wire suppliers.  More discussion 
      on this when Brian returns.  These documents are posted on the FDC procedures 
      web page.
 - Fernando has considered how we will make the connections from the HVTBs 
   to the power supplies.  He has identified a connector that will connect 
   to the baby cables soldered to the HVTB and the cables that go to the 
   power supply.  Bill is working to put the connectors into the 3D CAD
   model and to detail how they will be attached (as they are quite massive).
   Once we get some of these details worked out, we will discuss when we
   want to place the order.
 - Brian identified a group that can do our SEM wire studies.  Brian brought
   them our already prepared sample from our earlier SEM tests to see if they
   are content with our slide.  Note that our new SEM contact can be used to 
   study a sample of the cathode board that we received from Allflex.
   Fernando has prepared the sample and given it to DSC.

Cathode Planning

 - Roger heard from Allflex on Tuesday.  Five of the six 2 micron Cu
   boards were done and they are working on the sixth.  Once this is
   done, they will move onto the 5 micron Cu boards.  We should expect
   delivery in about 1 week.
 - We have not yet devised methods for handling the boards when they
   arrive from Allflex.  This will have to be developed once the boards
   arrive.  Presently we are planning on doing a battery of QA checks on
   all boards in the first order.
 - Bill has not done any more work on the system to cut the cathode edges.
   More to come when he gets back to this.
 - Bill has gotten a hole punch for cutting out the center of the cathode
   boards.  He will gather the necessary parts and pieces to do some
   test cuts.  It also turns out that Allflex will send us the punch that
   they had purchased for our job (before we told them not to do this).
   This work will proceed shortly.
 - The nominal plan as of now is to set the cathode tension on the
   boards and then to add the central hole.  We also are not planning
   to add additional gas holes in the active region of the cathodes.
 - DSC and Chuck have completed work (for now) on preparing the R&D
   schedule for the cathodes.  Copies of the plan have been circulated
   to all folks involved.  Please consult this regularly as you plan your
   work to understand better the order and the time assignments.  Contact
   DSC with questions.
 - Cathode flatness measuring system:
     * All parts n' pieces have arrived.  The machined parts from FSU
       have apparently not arrived.  Bill will check into this.
     * Mark has prepared the stabilizers for the granite table and is
       working on attaching the pieces for the rail installation.
     * The plan is to move the granite table to the EEL building early-ish
       next week.
     * Micah is standing by to install/attach his parts n' pieces to the
       system once Bill and Mark are done.
     * Micah reported on work that he has been doing to generate contour
       plots of the surface flatness from the 2D data.  He has sent around
       some sample plots for folks to look at, but he still has some work
       to do.
     * We will have to work out a time-sharing plan for the laser measurement
       head for the flatness measurements and the tension measurements.
 - Eugene has posted GlueX-doc-1090 containing all details regarding his
   studies on the cathode tension measurements and the allowed flatness
   variations.  He believes that if we can keep the flatness within 200 
   microns, we will be in good shape.
 - Brian and Bill should begin to layout a detailed outline for the cathode
   construction steps and circulate for feedback.

Wire Frame Construction

 - The frame that was used for our wire tension load test (which is 
   discussed in the FDC TDR) has been modified to include the pockets for the 
   rigid-flex assembly and the bolt holes.  It was machined to the 
   nominal I.D. and O.D. of our wire frames.  The foam core and the G10 
   skin were removed to an I.D. of 1032 mm to account for the problem 
   with the HV decoupling capacitor placement.  The plan is to redo our 
   loading tests and measure the in-plane and out-of-plane distortions of the
   wire frame up to a load of roughly 50 lbs (the full wire load is about
   35 lbs).  Bill is working on the FEA calculations to determine the
   loading limits for the frame.  This will also tell us how high in tension
   we can go with our load test, which uses a single wire down the middle
   of the frame (which is significantly worse that the distributed load of
   the real frame).
 - The nominal wire frame construction plan devised by Brian will be
   updated by Bill before the start of wire frame construction.  The
   current version of the plan is posted on the FDC web page under the 
   procedures link.  It will be updated when Bill is done working his magic.
 - We are presently planning on borrowing an A-frame for EEL 126 for the
   wire frame construction (that Tim arranged).  No other frames could
   be found in storage that we could claim.
 - The PCBs for the FDC will need to be handled by all folks involved with
   more care.  Many of the boards have sustained damage to the fragile
   lap ends.  The damage is not severe enough to cause any construction
   worries, but handling procedures do need to be established and followed.
 - Kim has started to move the decoupling capacitors on the back side of
   the STBs.  She has nearly completed work on one board.  All capacitors
   will be inward of D=1020 mm!  The o-ring lives again.

Test Frame Wire Winding

 - IUCF has supplied the official report from the Phase 1 wire winding
   continuation and an official budget for Phase 2.  We will have a
   teleconference with IUCF upon Elke's return from vacation.

Spacer Design

 - Since our last meeting more thinking about the design of our spacer 
   ring has been done.  Last week we discussed the possible advantages
   of laminating the ring directly to the face of the cathode.  Bill
   is souring on this idea as this would not give us the freedom to
   interchange the cathode boards due to the required positioning of the
   gas inlets and outlets on the spacer.  For the full-scale prototype
   Bill is content to live with a spacer ring with two o-rings.
 - Bill has not yet finalized a choice of material.  It looks like the
   best choice may be polypropylene.  He would prefer nylon-6 due to its
   superior mechanical properties, but nylon-6 absorbs water like a 
   sponge.  One problem with polypropylene is that it is very difficult
   to epoxy to it.  If this ring has o-rings on both sides, there is no
   problem here, but Bill needs to be able to attach the gas inlet and
   outlet tubings.  He described a number of potential work arounds.
 - We will be working to make a mechanical prototype as soon as the
   design is finalized.

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.
 - Bill has found some plastic threaded rods that could be use to 
   compress the stack.  We will be receiving some samples shortly and
   will carry out some loading tests.

Cooling System Tests

 - Fernando is in the process of writing up the results from his
   cooling system studies.  Stay tuned for the GlueX note.

Gas System Design

 - Slava is working on a preliminary layout of the gas handling system 
   for the CDC and FDC.  He provided two options for the FDC system design 
   that were essentially a basic version and a fancier version.  Slava's 
   design work was based on the original concept that Brian came up with 
   long ago.  Slava provided some drawings that DSC will review.  We will 
   then continue the design work as we have time.


 - 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.
 - Kim has provided a draft of a procedures document for the Phase 1 and
   Phase 2 wire frame PCB component attachment. She has merged this
   document with Fernando's cleaning and handling document.  The document
   is being finalized with some additional language on soldering iron
   temperature vs. time profiles.

Small-Scale Prototype

 - Simon and Fernando are in the home stretch on completing the specification
   of the cathode and anode ASIC dynamic range.  All required measurements
   have been completed and work is ongoing to finalize the test results in 
   the document.  What we have so far is posted as GlueX-doc-1070.
 - Yves Van Haarlem from CMU visited JLab yesterday to meet with Simon
   and Fernando on the work to specify the ASIC dynamic range for the CDC.
   Simon will post minutes from this meeting shortly on the GlueX wiki
   under the Tracking Meeting link.
 - We still have the lingering issue of the problematic x-y plots from the
   2-micron Cu cathodes.  Simon will revisit this problem by taking some
   new pulser calibration data to see if this makes the apparent problem
   go away.

CAD Model

 - We discussed a bit about making sure all relevant design features
   of the FDC are in the full CAD model.  Tim will have Slava work to
   put in the capacitors and resistors on the wire frame PCBs into the 

Work List

 - The FDC short-term work list has been posted on the FDC web site).  
   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.