<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>These are online at</div><div><br></div><a href="https://halldweb1.jlab.org/wiki/index.php/April_24,_2013_Tracking_CDC/FDC">https://halldweb1.jlab.org/wiki/index.php/April_24,_2013_Tracking_CDC/FDC</a><div><br></div><div><br></div><div>Regards,</div><div><br></div><div>Naomi.</div><div><br></div><div><br></div><div><br></div><div><br></div><div><p>Present: Curtis, Naomi, Beni, Simon, Lubomir
</p>
<ol><li>FDC Update
<ul><li> Package #3 is almost ready to be moved to JLab for tests using
the full electronics. Just missing one manifold that is being used in
the cooling system tests.
</li><li> The set up for the test of the cooling system in the EEL126 is
ready; still have to find a way to fill the chiller with Fluorinert and
then do the test.
</li><li> Preparation of the mock-up to practice the cabling of the FDC
at Blue Crab: half of the mesh cylinder is installed on one of the
installation cards but may need some improvements.
</li></ul>
</li><li>CDC Update
<ol><li>Naomi reported on the CDC channel testing - so far 113 boards
have been used for reading out data with HV of 2100 or 2200V, 50/50
Ar/CO2. Normally we would use 2.1kV but are going to 2.2kV now in order
to save time later on if we should need to exceed 2.1kV.
</li><li>Only 2 sets of 3 transition boards have had trouble in reaching
2kV, all the others went to 2.2kV without a hitch. The trip setting
used was 0.8uA total for 3 or 4 boards (72-96 straws). We will revisit
the less cooperative boards and use a trip setting of 8uA if necessary.
The boards usually draw very little current from the HV supply, 8nA or
less for 3 boards is typical.
</li><li>Naomi has documented some unusual CDC events on the page <a href="https://halldweb1.jlab.org/wiki/index.php/CDC_odd_events" title="CDC odd events">CDC_odd_events</a>. There are some more normal events shown on <a href="https://halldweb1.jlab.org/wiki/index.php/CDC_events" title="CDC events">CDC_events</a>. On page <a href="https://halldweb1.jlab.org/wiki/index.php/CDC_odd_events" title="CDC odd events">CDC_odd_events</a>
the top sets of events show pickup in strawless channels from huge hits
on the straws, the pickup is about 1/10 x the amplitude of the hit
signals; the lower sets of plots show some events where all 72 channels
were subject to huge oscillations starting at the cosmic ray's arrival
time. This was not seen on a subsequent run using the same straws. Apart
from that one noisy run, this occurs in less than 1% of events.
</li><li>The daisy-chain LV supply cable for the preamps is starting to
fall apart, 2 wires broke so far, Beni is going to look for some more
cables and/or minibridge connectors.
</li><li>Lubomir will talk to Slava about finding drawings for the HV
mounting blocks for the FDC in the hope that these can be copied for the
CDC.
</li></ol>
</li><li>fADC125 Update
<ol><li>Beni heard from Cody that he has almost finished testing 30
fadcs - he still has to do the full crate tests - and hopes to be able
to send some to CMU by the end of next week.
</li></ol>
</li></ol><div><br></div></div></body></html>