Minutes-1-21-2010

FDC Weekly Meeting

Date: January 21, 2010

Participants: Daniel, Simon, Beni, Eugene, Lubomir, Mark S., Bill, Kim, Fernando, Chuck, Glenn, Brian

Next Meeting: February 4, 2010

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Next FDC Meeting

 - The GlueX Collaboration meeting takes place next week. The next FDC
   Group Meeting will take place in two weeks.

General Construction Updates

 - We finally figured out the leakage/pressure problems that we were having
   with the prototype. We identified a leak in the ground plane in one of
   our cathode sandwiches. We are now scratching our heads trying to figure
   how/if it can be repaired. In addition to a leak in the ground plane
   itself, we seem to be leaking through the majority of the through holes.
 - As we have a problem with one of our cathode sandwiches, we have 
   reassembled the two-layer prototype and leak checked it. It is in very
   reasonable shape. We moved it into the cosmic ray test stand in a
   vertical position and its leak results and pressure readings are what we
   had measured in the clean room on the assembly jig.
 - Casey has hooked up the chamber grounds in preparation for the HV checkout 
   work that will proceed shortly.
 - Casey and Mark have completed a system that mounts around the prototype
   to hold a source and a trigger scintillator. The system allows for
   horizontal and vertical translations and verniers to locate the source
   position relative to the chamber.
 - The plan now is to give Beni and few weeks to work on testing the
   full-scale prototype. We will make a decision shortly on when to add the
   third layer back into the prototype.
 - We still have to add the stiffening pieces to the gusset arcs for the
   full-scale prototype to help reduce the flexing of the structure when it
   is rotated into a horizontal position. These pieces have been delivered
   by the shop and just need some holes drilled and tapped into the existing
   gusset arcs for attachment.
 - As we could not find a system to measure the oxygen contamination in our
   chamber gas, Bill will instead look into the system that we already have
   in our gas panel. It is an antique, that was last calibrated/used back
   in 1995.
 - We need to hook up the FDC prototype gas system to a UPS as we lost
   gas flow this morning due to some (suspected) power glitch.
 - The preliminary FDC stack assembly document draft is located at:
   /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. We will review this
   document after tests get underway on the full-scale prototype to update
   out-of-date or old procedures.

Frame Redesign Studies

 - Beni has gotten word that Mihajlo Kornicer has gotten his MC code working
   to study photon conversions in the detector. We expect preliminary results
   in the next day or two. Stay tuned.
 - The inner frame pieces for the wire frame and cathode frames have been
   delivered by the JLab machine shop. We will soon proceed to assemble 
   frames with these pieces and test their mechanical properties. Stay tuned 
   for details.

Wire Frame Update

 - The wire frame construction document is located at:
   /u/group/halld/Engineering/PRELIMINARY DOCUMENTS.
 - The parts of the jig to use for the wire electroplating operation
   are in our hands. They will be assembled as we find time.
 - We need to prepare a document for the electrical QA of the preamp
   connectors on the wire boards.
 - Kim is in the process of getting quotes for single piece boards from the
   board house. As soon as we have something that we understand, we will
   discuss it with the group.
 - DSC, Kim, and Fernando met on Tuesday to finalize plans for work on the
   wire frame circuit board work. Kim will be working full time on the
   redesign work starting on Monday of next week. 
 - We are working to remove the zig-zag overlap region on the join region
   for the STBs and HVTBs. We may even have to move to a 4-layer board for
   the HV side. Decisions will be made soon.

Cathode Update

 - The current draft of the cathode construction document is located at:
   /u/group/halld/Engineering/PRELIMINARY DOCUMENTS.
 - We need to prepare a document for QA/stuffing/cleaning for the cathode 
   boards and a similar document for the cathode daughter boards and ground 
   boards. Casey has a draft of a document that Mark S. began preparing. He
   will take this over and complete the document.
 - The cathode board material is now in Minnesota. It has been inspected by
   the distributor. They will send some photos to Roger. Roger will contact
   Allflex to see if they will store the board material until our order is
   ready. Stay tuned.
 - The next rigid-flex design meeting will take place in the first half of
   February.
 - We would like to push to get the cathode board procurement done on the
   time scale of this March. Stay tuned.
 - David Lawrence is working to give us input on the hole size in the
   cathode center. Stay tuned.

Cosmic Ray Test Stand

 - The current version of the full-scale prototype test plan is on the
   GlueX portal as (GlueX-doc-1304).
 - A while ago we focussed on the wiggles seen in the reconstructed wire 
   position from the cathodes (see log entry 419) in the
   FDC logbook. We believe that the periodicity seen is due to the algorithm
   Beni is using to determine the U and V centroids. Stay tuned.
 - To connect the full-scale prototype to the readout electronics, Fernando
   will design a simple translator board that allows connection from the
   24-channel preamp connector to the 16-channel connectors on the ADCs and
   TDCs. These boards should be ready in early February.
 - The signal cables for the full-scale prototype are being made up by
   Fernando's group and should be ready shortly.
   

Construction Updates

 - The wire sample checks are now in progress with the W&M folks. They 
   expect to be done by the end of the first week of February assuming no
   unexpected work comes up for them.
 - DSC will meet with the IUCF Associate Director overseeing the Wire Chamber 
   Lab on Friday to discuss planning for the Phase 3 contract.
 - Next IUCF meeting on Phase 3 preparations will take place in about 2 weeks.
   See the work plan at: Phase 3 Preparation Work
 - Master list on wire and cathode frame redesign work is located at:
   Frame Modification Work.

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.