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<div class="moz-cite-prefix">Hi Richard,<br>
<br>
the division in time is 10ns for the scope if I read the picture
correctly. So the change in peak amplitude<br>
is much faster than the 4ns sampling rate of the FlashADC. As a
result the flashADC is a very poor tool<br>
to be use as a peak sensing adc. I think you need to integrate the
signal to get results that you can compare.<br>
<br>
my half cent input,<br>
<br>
Beni<br>
<br>
</div>
<blockquote
cite="mid:CABfxa3RoXQv7vp7rXgTaCx9CZEh6yRCN2Q=PCajN1ribHMntmg@mail.gmail.com"
type="cite">
<div dir="ltr">Dear colleagues,
<div><br>
</div>
<div>We are working to obtain light yields for the first article
fiber bundle that was produced for the tagger microscope some
time back. We have run into a problem trying to interpret
what we see coming from the FADC250 module that is installed
in the data acquisition crate we are using for fiber QA tests.
Please see the plots on the wiki page linked below that
illustrate the problem we are seeing.</div>
<div><br>
</div>
<div><a moz-do-not-send="true"
href="https://halldweb1.jlab.org/wiki/index.php/Tagger_Microscope#Light_yield_tests">https://halldweb1.jlab.org/wiki/index.php/Tagger_Microscope#Light_yield_tests</a><br>
</div>
<div><br>
</div>
<div>When we look at the signals on the scope, we see one set of
amplitude ratios that clearly reveal the differences in light
yield resulting from different lengths of the fibers that are
covered in reflective paint. The results from the FADC are
much less distinguished, and disagree in the ratios of pulse
heights. Comments or suggestions as to what we are doing
wrong would be appreciated.</div>
<div><br>
</div>
<div>-Richard Jones</div>
</div>
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