Minutes-4-2-2009
From GlueXWiki
FDC Weekly Meeting
Date: April 2, 2009
Participants: Daniel, Bill, Beni, Brian, Mark S., Simon, Roger, Mark I., Eugene, Fernando, Kim
Next Meeting: April 9, 2009 @ 1:30 p.m.
Contents
Full-Scale Prototype Updates
- Cathode Board Orders
* Cathode boards: The PR is about to be signed. We have asked for a
few last minutes updates to the drawings. One is to move the artwork
on the end boards by 0.5 in. Also, remove the copper outer edge of
the boards (Bill will supply the appropriate radius). We most likely
will want the boards shipped flat using our transport box. A decision
will be made shortly along with final packing instructions. The final
order will have 7 sets of 2 micron Cu boards and 1 set of 5 micron Cu
boards.
* Corrosion issue: Roger is waiting to talk to the sales representative
at Allflex regarding these issues. Probably will include a second
deionized water rinse step.
* Cathode daughter boards: the PR will be ready when that for the cathode
boards goes out.
* Eugene has identified the accounts to be charged for these two PRs.
- Chamber Wire:
* We are waiting for the W&M SEM folks to finish training their folks
on the new SEM and then they will finish our wire QA checkout. Brian
will prepare a final QA report with photos and test results for all
wires when all studies are complete.
- Soldering Work: Kim will set up a meeting in a couple of weeks between
the FDC group and Greg's group for the soldering work for the cathodes
and wire frames. We can talk about our schedules and needs and work out
manpower details.
Wire Frame Update
- Status: Two wire frames (P4 and P1) have been wound. A third frame has had the wires attached but measurements of tension and wire position are pending. The linear transducer should have been sent off for refurbishment, but has been delayed due to IUCF red tape. Once it is sent out, it should be back and reinstalled in about 2 weeks. Keith will check on the status this week. - Folks who have not read Bill's IUCF trip report (GlueX-doc-1229) should look it over and provide feedback. Keith has just gotten back from a trip and will be looking it over to try to start filling in some missing numbers. - Bill has been updating the wire frame construction document based on lessons learned from the prototype frames. He is working to incorporate some more relevant photographs. A new version will be posted when his work is done. - Brian and Mark worked this week to electroplate Cu on the sense wires in a diameter close to what we will use in the final detector. This work was done with Tom Elliott. Five attempts were made on one of our existing full-scale wire frames. Ultimately a set of parameters (times, voltages, currents, polarities) were found that seemed to give a smooth Cu distribution with a final wire size about 4 times larger. We have not done any tests yet to see if the work is good enough for the final detector, and will have to think about it. The photographs taken will be built into the procedures document that Brian will be preparing. Bill will design an alignment jig and a system for attaching the electrical leads to the chambers. - The bearing for the rotatable platter for the Phase 2 soldering is in hand. Bill will complete the design and get the drawings to the shop shortly.
Cathode Construction
- We reviewed the cathode R&D timeline. The current schedule is being kept
on the mdrive at:
* Location: M:\halld\Individual-Schedules\FDC or for more sophisticated
folks, /u/group/halld/Individual-Schedules/FDC
- Progress updates:
* The G10 pieces for the cathode frames have arrived. The plan is
to begin production mode for the full-scale prototype frames so that
they are ready for the JLab machine shop at the end of this month.
The end of this month (beginning of May really) is when the horizontal
mill is available for our use.
* We made up a second 3 piece cathode panel with a set of our 5 micron
Cu boards. The boards looked very nice and we found fairly uniform
tension in the dimension across the strips. Along the strips, a
small gradient remained even though we had a cathode with no wrinkles.
It appears to the lack of symmetry of the boards (one connector on
side and 8 on the other) that the asymmetry may be unavoidable. Even
with this though, the tension gradient was only about 50 N/m, so
it seems reasonable. The tension gradient should be less with the
2 micron Cu boards as the copper on the 5 micron Cu boards is quite
stiff.
* Brian and Mark have made up a 2 micron Cu cathode panel and will
attach it to the transfer ring this week and perform some tension
measurements. We will most likely also make up the second 2 micron
Cu board for tension studies. We need to finalize our tension
settings and procedures with these boards for the full-scale
prototype.
* We discussed some simple modifications to the large G10 tensioning
ring that would improve the process. We will hold off on these due
to budget concerns for a bit until the budget issues are resolved.
* We have 5 prototype rigid flex assemblies (cathode daughter boards)
and 5 connectors for the preamp daughter boards. Greg Arnold's group
solder on the connectors. The boards will be fitted into a local area
on the cathode mechanical sandwich prototype to study access and
space conflicts to finalize the design. Hopefully this gets done in
the next week.
* Bill has been working on the cathode construction document. He will
circulate a draft shortly.
Cathode Flatness Measuring System
- Documentation of the system continues. See the FDC wiki page for details.
Stack Assembly Procedures
- 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 used 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. - Bill has done some ANSYS modeling to better study the connector that goes from the daughter board card to the cooling loop. These will be added to Fernando's note.
Documentation
- 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.
Cosmic Ray Test Stand
- We will be moving the FDC cosmic ray test stand from the Test Lab back to the EEL building. Beni is working on designing the room layout in EEL 126. The move of the cosmic ray test stand from the Test Lab does not need to happen in April as the planned magnet tests have been detailed for the time being. Still, we need to get things over to EEL for testing. - 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. - We would like to put together a bench test plan for the full-scale prototype within the next couple of weeks. This preliminary test plan will be used to provide information on what test stand fixtures to support the chamber we will require. Bill can then work on the design and get things prepared in the shop. Also, we would like to layout a design for the electronics before too much longer so that we can reduce time from when the full-scale prototype is constructed to when we get into the test plan.
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.
