Difference between revisions of "Minutes-11-11-2010"

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- Bill showed his model of the wire stringing table (linked above). He made improvements in the height adjustment of the strongback. Eugene
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- Bill showed his model of the wire stringing table (linked above). He made improvements in the height adjustment of the strongback. The movement system will be attached to the sides of the table and movable over the chamber. There were different suggestions how to install it so that it's not obstructive when stringing. We discussed also how the calibrate/set starting point for the position measurements. 
  
- Bill send the strongback back to the machine shop for some modifications. Working on the spool holder and the weights (out of steel). Bill explained how the
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- Stepper motor controller: Beni tried to use JLab controllers from the target group to control the motor. It works only without using the encoder. We will order the controller
movement system will be attached to the granite table. This may require drilling additional holes in the granite, but this time horizontally.
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- Wire tensions: Lubomir investigated to effect of the wire offsets on the gain and on the strip signals. As long as the tension is above 15g on the sense wires and above 60g on the field wires, the effects on the chamber operation are small. We can use as nominal tensions: 20g and 132g based on Dan's estimates and Bill's correction of the field wire linear density. However, too high tension on the field wire is not needed (since we can tolerate some difference in the gravitational sag) and may cause frame deformation. Bill will estimate the deformation effects and after that we can decide about the tension values.
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== Full-scale prototype tests ==
 
== Full-scale prototype tests ==

Revision as of 19:11, 11 November 2010

November 11, 2010 FDC meeting

Tentative Agenda

  1. Production (David)
    • Blue Crab status sketch
    • Frame lamination
    • Production plan
  2. Electronics (Fernando, Chris, Roger)
    • Update on PCB inspection
    • Other
    • Cathode foil production
    • Rigid-flex procurement
  3. Engineering (Bill, David, Beni)
    • Wire stringing status model ; stepper motor controller.
    • Other
  4. Full-scale prototype tests
  5. Other


Minutes

Participants: Eugene, Fernando, Bill, Casey, Mark, Chris, Roger, Simon, Beni, and Lubomir.

Production

- They are going to install phones and work on the Internet today at Blue Crab. We can now use heaters at low temperatures; must be above 60degF for gluing.

- By next Wednesday expect to have all the wire frames laminated. 18 frames came back from Vision machine after fly cut. They started there also the cathode frame production.

- Dave made the next version of the production plan. We start production in March 2011, the first package will be ready by September 2011 and then every ~4 months we plan to have a new package. According to the plan we will produce chamber by chamber serially, so that we can test them at the same time.

Electronics

- Chris received all the populated PCBs. The inspection showed that the packaging was not done correctly (as for the first article) and as a result 8 PCBs (3+3+2 of different types) had broken tips up to 1.5". Bill thinks that this is not crucial and one should be able to glue the PCBs together. The main problem is that the PCBs have much more flux than the first article PCBs; the latter also were not acceptable. Fernando discussed the issue with the company and we will ship all the PCBs back for cleaning. In addition Chris found some other problems that are not crucial (Fernando). Find many pictures from the PCB inspection at M:\halld-electronics\Documents\FDC\Populated FDC First Articles on Windows, or at the /group/halld-electronics/Documents/FDC/Populated FDC First Articles on linux.

- Roger received the Gerber files from Allflex adjusted to the production, for final approval. Bill and Fernando looked at them and agreed. The first cathode foils will be produced in the week of 11/29-12/3. The rigid-flex contract was awarded with a company also near Minneapolis. We will have the first article also by the end of the month.

- Cathode foil inspection: George Jacob suggested moving the two tables inside the Hall B clean area in the evening before the week of 12/6-12/10, using the roll-up door, so that the particle count goes down by 12/6. We have one 2x5' table and need to find another one. Fernando: need to check the connectivity (resistance if measurable) for each strip, but also between the strips; the latter was an issue before. Fernando will send David the QA procedure for the cathode foils and the PCBs.

Engineering