Minutes-6-25-2009
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FDC Weekly Meeting
Date: June 25, 2009
Participants: Daniel, Simon, Bill, Beni, Rich, Mark S., Brian, Roger
Next Meeting: July 2, 2009 @ 1:30 p.m.
Contents |
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General Construction Updates
- There was a problem with the quantity of the fiber-reinforced gusset
pieces due to a communication problem with the shop. We only got half
of the pieces required. To save on costs and time, we ordered a second
set made from aluminum that will be done by the middle of July.
- The parts for the assembly jig on which the detector stack will be
constructed have been delivered. Mark S. and Brian will assemble the
jig when they have time and do some test fits.
- Bill will take on the preparation for a stack assembly document. A
draft will be prepared before assembly of the full-scale prototype and
then fleshed out during the process with relevant photographs taken.
- Cable preparations:
* The LV cables have arrived and will be tested in the near future.
* The parts n' pieces for the HV cables are now all in hand and
construction and testing will begin over the next several weeks.
* The signal cables and connectors are in hand and Mark and Brian will
begin construction as they have time.
* We still need to decide how much of the outer jacket and braid will
be stripped off the signal cables.
- We are having short daily meetings to review the work on the full-scale
prototype construction and to ensure that any snags or problems that
come up are immediately addressed.
- Brian and Mark S. will begin making up the composite frames for the
two gas windows. They should be ready within a couple of weeks.
- Mark S. will prepare the order for the cables that will be used to
attach to the cathodes for the external ground. He will also order the
sealing epoxy that is used to cover the conducting epoxy.
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Wire Frame Update
- Rich did a series of HV tests on each of the wire planes. There was a problem on one board of one frame. Upon inspection we found a sizeable number of wires that were not soldered to the solder pads. After discussion internally and with IUCF, it seems that the likely culprit is that due to the non-flatness of the wire frames, the wires were not in contact with the board in the location of the solder pads and they popped out of the solder. On the frame that we have inspected, there were about 30 such problems, all but 1 were with the sense wires. Armen and Brian did all of the repairs on the known wires. Rich will recheck all connections and the frame will be fully cleaned again. Rich will then move to inspect the remaining boards in turn. This problem is a real time sink and is taking time away from cathode construction. - We need to have a dedicated meeting to design what the schedule for work on the Phase 3 wire winding will be. The highest priority for work scheduling will be doing work on upgrades of the wire winding facility. This includes a better strongback design, the design and construction of precision combs, modification to the wire winding table, and a list of other items with the system. Stay tuned, more to come. - We are pushing hard to begin wire frame construction early next year and begin wire winding before the end of 2010. Hopefully this can all procede. We are now working to complete the simulation studies with Simon to determine if we want to offset neighboring wire layers. More to come in the upcoming months. - The wire frame construction document is located at: /u/group/halld/Engineering/PRELIMINARY DOCUMENTS. He will include the information on the wire electroplating process as well. - Bill is now designing the jig for the wire electroplating operation and it will be ready for submission to the shop at some point in the future. We will make a decision shortly if/when we will electroplate the wires for the full-scale prototype. - Brian received the SEM scans for our wire from the W&M folks. He will generate a final QA report with photos and test results for all wires in the next several weeks.
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Cathode Update
- Progress updates:
* Mark S. has completed edge sealing and gas hole inclusion and sealing
in 3 of the 8 cathode frames. He is working on this as he has time. He
has come up with a new application system for the sealing epoxy that
is faster than the hand application.
* The edge cutting on all cathode boards was completed last week.
* Brian and Mark S. laid up another panel set using the new taping
procedures. The joints between neighboring boards look fine, but DSC
was concerned that there was too much rough board handling and we
we revisit construction steps with the next cathode board layup that
should begin tomorrow and be completed on Monday. For now this board
is stored in the clean room and will be attached to a tranfer ring
shortly.
* We have a plan in place to get the completed cathode boards back under
environmental control. Hopefully this will happen next week.
* The 2 micron cathode board that had been in the tensioning system for
a couple of weeks was laminated to its frame. The procedure had only
moderate success as the procedure used during the vacuum bagging step
left a sharp annular crease about 2 inches in from the frame I.D..
The procedure will be modified to eliminate this problem. After the
frame was attached, the tension transfer ring was cleaned off and sent
to the shop to be modified like the other ring. The work on the ring
was completed in a day and the ring returned to us.
* The cathode panel that was laid up last week as installed into the
tensioning system with the modified transfer ring. We were quite
pleased with the redesign. The board will be tensioned next week
when Eugene returns from travel. At this time, Eugene will transfer
knowledge to Mark S. and Brian on how to tension the boards.
* To finish the flatness scans of our 5 micron board, Micah has
completed a flatness scan of the granite table surface. Data analysis
is in progress and we hope to be done with the measurements on this
board early next week so that it can be put under environmental
control
- We now have received the full order of rigid-flex assemblies. The parts
have been passed onto the fast electronics group to solder on the
preamp card edge connectors and the addressing resistors. The problem with
the locating holes being too small does not seem to be a problem with
these boards according to Roger. We need to double check this.
- Bill has been working on the cathode construction document. He has
circulated a draft for comment. The file is located at
/u/group/halld/Engineering/PRELIMINARY DOCUMENTS. As new pictures are
taken, they are being incorporated. As procedures are modified or
fine tuned, the document is being updated.
- We are still working to finalize the PR for the 2 micron cathode board
material. We now have word from a second source that they should be
able to produce our board material. This was the same company that
provided our 5 micron board material. We expect a budgetary estimate
in the next day or two and then will move to finalize our order for the
full production stock. Stayed tuned for new developments.
- 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.
- Bill would like to modify the design of the system for tensioning the
cathodes to enable a better technique for vacuum bagging. The big issue
is to get the air bubbles out and the system is upside down relative to
what he wants it. We will talk more next time on this.
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Cooling System Tests
- Fernando is in the process of writing up the results from his cooling system studies. Stay tuned for the GlueX note. He indicated that he is back to work on this document and it should be done shortly.
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Cosmic Ray Test Stand
- Beni is continuing work to setup the cosmic ray telescope and test system in EEL 126. He would like to have it all up and functioning and understood before the end of June. Progress is being made connecting up all detectors and getting CODA working. - We still have some mysterious behavior with the small-scale prototype response with wiggles in the X vs. Y distributions that need to be understood. We decided to have a separate meeting to discuss what work we would like to do on the small-scale prototype. - Beni has started a bench test plan for the full-scale prototype and we discussed his preliminary document briefly. He will circulate it for feedback and we will continue to flesh it out. We want to make sure that we do some checks of gas leakage with the prototype. We agreed that the best procedure would be to use the P5 gas mixture (non-flammable). - Bill has designed a system to rotate the prototype from vertical to horizontal. The drawings have been submitted to the machine shop and the pieces should be delivered in about 2 weeks. - Safety paperwork for the cosmic ray test stand has been turned over to Bert for review. Upon approval we will fill the chambers with gas and be able to turn on the high voltages
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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.
