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User name A. Camsonne
Log entry time 18:43:44 on August 25, 2009
Entry number 285968
keyword=Compton electron detector noise study and tests
I added the ferrites with the help of Jack this morning, I haven't really
seen a major.
I might have found an interesting correlation. Noise if bigger when at
lower threshold indicating still a bit of crosstalk. So when going down
from 17 to 13 or 10 the noise increases which could explain the lack of
major improvement of efficiency when lowering the threshold.
I think one possible fix could be to use only the lower part of the
detector and put a metalic plate instead of a discrimator board as
additionnal shielding.
I will check that tomorrow during the pass change.
I also try to ground a bit better the right side but have not seen major
changes so far. When it is quiet background is still aound 14 mV. So
better grounding shielding could still help.
A copy of this log entry has been emailed to: brossard@clermont.in2p3.fr,hyde@jlab.org
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