<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div><div><br></div><a href="https://halldweb1.jlab.org/wiki/index.php/November_7,_2012_tracking_CDC/FDC">https://halldweb1.jlab.org/wiki/index.php/November_7,_2012_tracking_CDC/FDC</a><div><br></div><div><p>Participants: Curtis, Naomi, Beni, Simon, Lubomir, Mark
</p>
<ol><li>FDC Update
<ol><li>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.
</li><li>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.
</li><li>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.
</li><li> 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.
</li></ol>
</li><li>CDC Update
<ol><li>Wiring the transition boards was completed last week. See <a href="http://www.halld.org/CDC/index.html" class="external text" rel="nofollow">CDC Photos</a>
</li><li>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.
</li><li>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.
</li><li>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).
</li></ol>
</li></ol><div><br></div></div></body></html>