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User name Alex / Bob
Log entry time 08:34:49 on November13,2009
Entry number 299485
keyword=Compton statusSome Compton runs were taken last night. The vacuum work did some
good. We can turn the photon detector on, but we are limited to
approx. 1500V on PMT. Might be able to go a bit higher.
Consequence of this is the FADC DAQ does not work, but the
counting DAQ is producing results because it uses an amplifier
to boost the photon signal. See fig 1 for run 20962.
There is still some background, but it's better (fig 1).
I think Alex's plan is to try simple, LOW risk things to reduce
background (steering in chicane, etc).
The Edet was not in the beam yet. Alex may put it in later to see
if it can withstand the rates. If so, we may try to measure effic.
The default plan if we can't make improvements today is to run
like this for the weekend. At least we see some results (fig 1,
run 20962).
FIGURE 1
FIGURE 2
