Difference between revisions of "August 31, 2011 Tracking CDC/FDC"

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== CDC Update ==
 
== CDC Update ==
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#minutes still under edit - below are old minutes from a previous mtg
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#Straw installation - the final row (28) was started this week, 20 straws are in place so far. All the straws for the layer have been cut.  When gluing in the straws yesterday the techs noticed that the straws were approx 1mm shorter than usual, this was tracked to the end-stop on the cutting bench having been displaced slightly, so the straws had 2mm gap rather than the usual 1mm. 90 straws have had donuts glued in already. These are being glued into the chamber with a small wedge underneath to maintain the gap at the upstream (Al) end.  This will later be filled with nonconducting epoxy.  For the 120 remaining donutless straws we will test to see if the donuts can be retracted 0.5mm each before gluing them in place whilst retaining the correct orientation.
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#Straw installation - the last stereo row (24) is nearly complete.
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#Tension tests - the wire tension was remeasured in rows ??  No more broken wires were found, the one wire found with low tension (20g) will be removed and restrung.
−
#Tension tests - 6 broken wires were found in the 6 strung layers (and will be replaced during the next stringing session).  All the wires did pass continuity testing soon after stringing; the tension measurements were made several weeks afterwards. The wires all broke in or near to the crimp pin.  We plan to remeasure the tension in the other wires.
+
#Gary has been working on the clamshell hub, joining 3 sections approx 4 ft long by splicing with a separate 3 inch long piece of G10.  After gluing in the splices and bending the hub to shape the splices snapped.  He will try again with aluminum splices.
−
#A few of the CDC photos taken by CMU's photographer are on line.[[http://halld.org/CDC/layer_23/index.html CDC photos]]
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#Tim reported that the cheeseplate contract has been awarded to a local company.
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#The wire hookup prototype is finished and is being used for wiring practice. [[http://halld.org/CDC/preamp_hkup/index.html PCB hookup prototype]]
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#The inner hub has arrived at CMU.
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#Naomi made a slight improvement to the prototype CDC resolution by improving the timing by sending the logic signals from scintillator discriminators and coincidence into the fADC.
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#Tim would like to call a meeting later in the week to discuss the drawings and remaining components, including
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#Tim has sent out the cheeseplate spec to some vendors for comment prior to bidding. Labelling every hole will be cost-prohibitive so this might be reduced to 10% of the holes.  We will have to accept stock material (polycarbonate), Tim will double-check that clear polycarbonate was specified.
+
a labelling system (from Beni) for the HVB standoffs.

Revision as of 12:18, 31 August 2011

Meeting Time and Place

Wednesday August 31, 2011 at 11:00am At Jefferson Lab, the meeting will be held in F326

Connections

To connect from the outside, please use ESNET

  1. ) ESNET: 8542553
  2. )To connect by telephone, dial:
  • You can look up toll-free number at http://www.readytalk.com/intl
  • US and Canada: (866)740-1260 (toll free)
  • International: (303)248-0285 (toll call)
  • enter access code followed by the # sign: 3421244#

Agenda

  1. Announcements
  2. FDC Update logbook
  3. CDC Update

Minutes

Participants: Curtis, Naomi, Beni, Eugene, Elton, Simon, Lubomir, Dave, Mark, Tim

FDC Update

CDC Update

  1. Straw installation - the final row (28) was started this week, 20 straws are in place so far. All the straws for the layer have been cut. When gluing in the straws yesterday the techs noticed that the straws were approx 1mm shorter than usual, this was tracked to the end-stop on the cutting bench having been displaced slightly, so the straws had 2mm gap rather than the usual 1mm. 90 straws have had donuts glued in already. These are being glued into the chamber with a small wedge underneath to maintain the gap at the upstream (Al) end. This will later be filled with nonconducting epoxy. For the 120 remaining donutless straws we will test to see if the donuts can be retracted 0.5mm each before gluing them in place whilst retaining the correct orientation.
  2. Tension tests - the wire tension was remeasured in rows ?? No more broken wires were found, the one wire found with low tension (20g) will be removed and restrung.
  3. Gary has been working on the clamshell hub, joining 3 sections approx 4 ft long by splicing with a separate 3 inch long piece of G10. After gluing in the splices and bending the hub to shape the splices snapped. He will try again with aluminum splices.
  4. Tim reported that the cheeseplate contract has been awarded to a local company.
  5. The inner hub has arrived at CMU.
  6. Tim would like to call a meeting later in the week to discuss the drawings and remaining components, including

a labelling system (from Beni) for the HVB standoffs.

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