Difference between revisions of "Minutes-8-25-2011"
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#* Results with new gas mixture: [http://www.jlab.org/htbin/PHYSICS/halld/enote112.pl?nb=notebook&action=view&page=573] | #* Results with new gas mixture: [http://www.jlab.org/htbin/PHYSICS/halld/enote112.pl?nb=notebook&action=view&page=573] | ||
# Other: [http://www.jlab.org/Hall-D/detector/fdc/movies/FDC_1_1.mov how to assemble a package] | # Other: [http://www.jlab.org/Hall-D/detector/fdc/movies/FDC_1_1.mov how to assemble a package] | ||
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= Minutes = | = Minutes = | ||
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- Dave: yesterday finished with stringing and taping wire frame #6, today did the position measurements and by the end of the day the wires will be glued. The cutter is now again operational and the techs will continue with cutting the foils for the cathode set #7; working also on the flaps for the cathode type 2 from set #6. | - Dave: yesterday finished with stringing and taping wire frame #6, today did the position measurements and by the end of the day the wires will be glued. The cutter is now again operational and the techs will continue with cutting the foils for the cathode set #7; working also on the flaps for the cathode type 2 from set #6. | ||
| − | - HV cap problem (see pictures linked above). Everybody was surprised by the size and the abundance of the solder balls: 1-2mm (compared to the gap of 4.5mm between the pads) under more than 50% of the caps. This is the result from two wire frames that were re-soldered by Anatoly. The leakage current after re-soldering went down to several nA for the whole frame. | + | - HV cap problem (see pictures linked above). Everybody was surprised by the size and the abundance of the solder balls: 1-2mm (compared to the gap of 4.5mm between the pads) under more than 50% of the caps. This is the result from two wire frames that were re-soldered by Anatoly. The leakage current after re-soldering went down to several nA for the whole frame. Not all the boards are like these: when we started testing the capacitors a month ago, Anatoly re-soldered the capacitors on another board we didn't see such solder balls there. |
| − | + | After some discussions we agreed that it is worth informing the company that populated the boards. Chris will take care of the communications with them. Eugene: probably it's not worth pursuing this problem legally, but suggested to consult with the procurement. | |
== Engineering == | == Engineering == | ||
| + | |||
| + | <!-- | ||
- Bill showed pictures (linked above) of the deadened area of one of the samples made by the W&M microscope. The surfaces, including the transition areas, look well polished and free of any sharp edges. The thicknesses along the wire and also for the different wires are very similar of about 66-68 microns, except at the very end of the deadened area where it is ~57 microns. Bill will look also at the last wire sample. | - Bill showed pictures (linked above) of the deadened area of one of the samples made by the W&M microscope. The surfaces, including the transition areas, look well polished and free of any sharp edges. The thicknesses along the wire and also for the different wires are very similar of about 66-68 microns, except at the very end of the deadened area where it is ~57 microns. Bill will look also at the last wire sample. | ||
Revision as of 15:57, 25 August 2011
August 25, 2011 FDC meeting
Contents
Agenda
- Production Construction Tracking (Dave)
- Engineering (Bill)
- Electronics update (Chris)
- Chamber testing at EEL126 (cell#2) (Beni)
- Results with new gas mixture: [6]
- Other: how to assemble a package
Minutes
Participants: Eugene, Bill, Dave, Beni, Chris, Simon, and Lubomir.
Production
- Dave: yesterday finished with stringing and taping wire frame #6, today did the position measurements and by the end of the day the wires will be glued. The cutter is now again operational and the techs will continue with cutting the foils for the cathode set #7; working also on the flaps for the cathode type 2 from set #6.
- HV cap problem (see pictures linked above). Everybody was surprised by the size and the abundance of the solder balls: 1-2mm (compared to the gap of 4.5mm between the pads) under more than 50% of the caps. This is the result from two wire frames that were re-soldered by Anatoly. The leakage current after re-soldering went down to several nA for the whole frame. Not all the boards are like these: when we started testing the capacitors a month ago, Anatoly re-soldered the capacitors on another board we didn't see such solder balls there. After some discussions we agreed that it is worth informing the company that populated the boards. Chris will take care of the communications with them. Eugene: probably it's not worth pursuing this problem legally, but suggested to consult with the procurement.
![[1]](http://www.jlab.org/Hall-D/detector/fdc/images/P8220381.JPG){kind=link}
![[2]](http://www.jlab.org/Hall-D/detector/fdc/images/P8220383.JPG){kind=link}
![[3]](http://www.jlab.org/Hall-D/detector/fdc/images/P8220385.JPG){kind=link}
![[4]](http://www.jlab.org/Hall-D/detector/fdc/images/P8220373.JPG){kind=link}
![[5]](http://www.jlab.org/Hall-D/detector/fdc/images/P8220375.JPG){kind=link}