Minutes-1-22-2009
From GlueXWiki
FDC Weekly Meeting
Date: January 22, 2009
Participants: Daniel, Simon, Brian, Mark I., Mark S., Bill, Beni, Fernando, Micah, Elke, Dave, Roger, Eugene
Next Meeting: February 5, 2009 @ 1:30 p.m.
Contents
Full-Scale Prototype Updates
- Elke raised the issue of signed drawings for the FDC prototype. She
asked that we follow established lab procedures for getting drawings
signed. This entails that at least one person outside of the work
being done look them over. Bill will talk with Tim about making this
happen.
- Procurements:
* Roger is waiting on a call back from the company making the rigid-flex
assemblies. He stated that our order should be here by the end of this
month.
* The replacement order for the Rohacell should arrive any day now.
Bill has had some trouble getting in contact with the company, but
he will follow up on this.
- Wire QA studies:
* Brian has provided samples of our sense and field wires to the
SEM folks, they will complete the mass spectroscopy analysis and
get back to us shortly.
* Brian will prepare a final QA report with photos and test results
for all wires when all studies are complete.
* Beni circulated an updated draft of the wire QA specifications
based on my earlier document and additional feedback from Steve
Christo. DSC will look over and give feedback.
- Mark S. is also 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.
- The Hall A folks have inquired about use of the clean tent. Brian has
had some discussions, but not enough is known about their time line.
Brian will send the Hall A folks to DSC to finalize the plans.
Calibrations
- Fernando has posted a new GlueX document entitled Calibration of the CDC and the FDC Readout Electronics. Folks should look this over and we can talk about it at a future tracking meeting or FDC meeting.
Wire Frame Construction
- All Rohacell/G10 laminates have come back from the machine shop and are within the promised specifications. - Two wire frames have been successfully laminated to the PCB annuli and a third is in the vacuum-bagging facility at present. The fourth frame will be done tomorrow. - All completed frames have a thickness variation of within a mil! This is outstanding - The last step to complete the wire frames is to use epoxy to seal the Rohacell along the inner diameter and the outer diameter, as well as the through-holes. We should be ready to start packing the frames (and the sense and field wire spools) into the shipping crate on Tuesday of next week. - Brian/Mark will alert shipping and receiving so we can try to get the crate to IUCF by the end of next week. - Elke has sent email to Vladimir Derenchuk with an official schedule update and to request information on when they will be ready to start working. She also alerted them that we want Bill there for some portion of the work. - Kim needs to complete the PCB stuffing/cleaning document. This should be done by the middle of February. She has made a request for the relevant information from Fernando so that she can finish this document.
Cathode Planning
- We reviewed the cathode R&D timeline. Folks are reminded to pass on
progress updates to Chuck every Wednesday. 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 cathode edge cutting system has been assembled. Bill is not
fully satisfied with the clamp design but thinks he has a satisfactory
work around. Mark will put some attention on doing test cuts after
the wire frames are done and gone.
* No progress on completing the cathode construction document. Stay
tuned.
* The laminates that were made up for the cathode frames for the
full-scale prototype were made and found to be too thin in places.
Mark will make up another pair with improved QA selection for the
foam. These are needed in the shop for machining ASAP as the window
given to us by Casy is closing.
* Brian will start laying up 2 sets of cathode planes for the
full-scale prototype. He will use blank Kapton for this. He will
not need the edges cut with the new system.
* Eugene stated that he believes the average cathode tension should
be set to 500 N/m after his most recent analysis.
* We discussed more about the artwork distortions on the cathode boards
that will result from the tension. We expect no more than 3 mm across
the strips and maybe another 0.5 mm at the tape joints. Instead of
worrying about the complications of using scaling factors in the
artwork, we will opt for the simplest solution. Allow for the
stretching and correct for the increased strip pitch in software.
To proceed to the next step, Roger will work to modify the board
design to allow for appropriate clearance around all through-holes
to accommodate this stretching. The connections for the rigid-flex
assemblies have enough slop for shifting the connection point to
the cathode board.
* Roger has started dialog with the cathode board house. We need to
finalize exactly what we plan to order. Probably 6 more sets of
2 micron Cu boards. We currently feel that we will not have to
resort to using 5 micron Cu boards given the flatness of the boards
in the first order.
* We discussed that the time line for the next cathode order is about
1 month. Roger is aware of this and will start on the board redesign
work.
* We discussed plans for using an optical system to measure the
cathode board distortions after they have been tensioned. Presumably
we could use the horizontal mill in the machine shop using their
camera system. This will most likely be needed in about 6 weeks.
* Bill raised a clearance issue on the space between neighboring
cathodes. The ERNI power/address connector on several boards is in
conflict with the positioning of nearby cathode daughter boards. Two
solutions were discussed, the first is to use thicker Rohacell in the
cathode frames to increase separation, the second is to redesign the
cathode daughter boards to rearrange the layout. Roger will look
into this last option.
Cathode flatness measuring system
- Documentation of the system continues. See the FDC wiki page for details. - Drew has offered to use Detector Meister money to buy another laser for the FDC effort so that we don't have to share one between the tensioning facility and the flatness facility. Brian will put the PR together. We will get another computer that Brian has so that we can have two separate systems.
Spacer Design
- Bill has completed the prints for the spacer construction and will pass them onto the machine shop shortly. - The material order will arrive soon. This work is not super high priority and we will use it as filler work in the machine shop.
Stack Assembly Procedures
- DSC, Brian, 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 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.
Small-Scale Prototype
- We will be moving the FDC cosmic ray test stand from the Test Lab back to the EEL building. This move should be completed in the next 6 months or so.
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.
