Minutes-3-26-2009
From GlueXWiki
FDC Weekly Meeting
Date: March 26, 2009
Participants: Daniel, Bill, Beni, Brian, Mark S., Simon, Roger, Mark I., Eugene, Fernando
Next Meeting: April 2, 2009 @ 1:30 p.m.
Contents
Full-Scale Prototype Updates
- Cathode Board Orders
* Cathode boards: The PR is waiting for a budget code that Roger will
get from Eugene. The PR will be on Eugene's desk before the end of
the week. The total for the order is roughly $13k. Roger has gotten
some additional packing instructions from Brian (no securing tape and
non-static paper) that Roger will put into the order. We have been
given an initial delivery time of 6 weeks. Roger will see what he
can do to push this.
* Corrosion issue: Simon compared photographs of the boards taken upon
delivery to the latest photos and it does not seem the corrosion is
worse now than when the boards arrive (good news). We will still pass
our QA concerns to Allflex and they may opt to do another rinse stage.
* Cathode daughter boards: The PR is waiting for a budget code that Roger
will get from Eugene. The PR will be on Eugene's desk before the end
of the week. The turn around time for the order is a couple of weeks.
Roger will talk to Greg Arnold's group about doing the board stuffing
as soon as the boards come in. Fernando will have a scheme for
the addressing resistors by that time.
- 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.
- Mark S. is responsible for upkeep of the list of procurements for the
full-scale prototypes.
* Location: M Drive/halld/Electronics, or for more sophisticated folks,
/u/group/halld/Electronics.
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 has been sent off for refurbishment and should be back and reinstalled in about 2 weeks. - Bill was at IUCF last week observing, documenting, and interacting with the IUCF team. He prepared a trip report that has been posted as: GlueX-doc-1229. The relevant folks should look this over and consider Bill's comments and recommendations. The report has been forwarded to IUCF as they have some blanks to fill in. At some point in the near future, we will have a phone meeting to go over this issues. - Wire combs: The wire positioning on the IUCF winding table is not as well controlled as it could be. We may ultimately design precision combs to help locate the wires. Several ideas were discussed for Phase 3 winding, but we won't take this too far until we get closer to Phase 3. - 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 were supposed to spend some time honing the procedure for electroplating Cu onto the sense wires with one of the JLab chemists (Tom Elliott) but he has been sick this week. This work has been rescheduled for next Monday. All of the parts n' pieces are in hand. 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 are on order and are due at
JLab this week. We will start manufacture of cathode frames when
the order arrives.
* From available G10 pieces, a third cathode ring was made and
machining completed in the JLab machine shop.
* All of the cathode boards from our first board order were tripped
using our nice cutting facility. Photographs and notes will be
given to Bill to include in our construction document.
* We made up a 3 piece cathode panel with a set of our 5 micron Cu
boards. The two seams were absolutely beautiful. During attachment
to the transfer ring, wrinkles developed on one edge of one of the
boards. We installed this cathode in the tensioner and Eugene
measured the tension along one diameter that met up with the wrinkles.
The board had a steep gradient in measured tension from 600 N/m
on one side to 450 N/m on the other. We could not find a way to
adjust the tensioner to remove the gradient. We will set this board
aside as it is out of spec (i.e. it will be removed from the transfer
ring and stored for later use, if needed).
* The wrinkles that formed in attaching the transfer ring occurred due
to a flaw in the process that has been corrected. Our second
5 micron Cu board was laid up and will be attached to the transfer
ring this week. We will then see how the tension varies across the
board early next week in the tensioning fixture.
* Our next cathode layup will employ a set of our 2 micron Cu boards.
* We have 5 prototype rigid flex assemblies (cathode daughter boards)
and 5 connectors for the preamp daughter boards. We will have Greg
Arnold's group solder on the connectors. The boards will then be
fitted into a local area on the cathode mechanical sandwich prototype
to study access and space conflicts to finalize the design. This
should be done by the end of 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.
