[Halld-tracking-hw] Tracking meeting minutes posted

[Naomi Jarvis]

https://halldweb1.jlab.org/wiki/index.php/November_7,_2012_tracking_CDC/FDC

Participants: Curtis, Naomi, Beni, Simon, Lubomir, Mark

FDC Update
There was over-pressure in the first package over the weekend. It was caused by the bubbler that at higher flow somehow blocked (or significantly reduced the flow of) the exhaust line. No issues with the package were found due to the over-pressure.
We started testing the second half of the first package this week: so far no problems. The cells from the first half showed lower current than before.
Beni and Simon are trying to estimate the wire resolution of the third package. Beni estimated ~250 microns averaged resolution for a configuration with two parallel wires and similar drift times.
We are discussing the possibility to move the testing set-up to Blue Crab. Fixing the HVAC at 126 requires at least $20k and will not happen soon.
CDC Update
Wiring the transition boards was completed last week. See CDC Photos
Gary made some a cooling ring with 32 holes in (at a 45 degree angle to the endplate) to blow air onto the electronics and fitted it to the chamber temporarily.
There was a fairly large discrepancy between the volume of air being blown into the chamber and the volume coming out through the bubblers. This is thought to be partly due to a gap in the sealing of the temporary downstream plenum. Whilst the chamber was being inspected for potential leaks, cracks were spotted in the neoprene U-channels forming part of the upstream plenum wall. These will be covered with DP-190 to seal the cracks. Then we will refit the temporary plenum (gasbag) and compare gas flow in and out.
Naomi mentioned that she'd measured the pedestal noise with and without the prototype attached to the HVB+preamp (with HV on, off and disconnected) and adding the prototype made very little difference (added 1.5 to a sigma of 15 ADC bins, range 0-4095).

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