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Alex,<br>
<br>
I will keep the idea of another beam test in the Spring in mind. We
have the new preamp design finished, and a run of 3 new pcb's is out
on order to the manufacturer now. A new order of 35 Hamamatsu
SiPM's has just gone out as well. We should have two new completely
instrumented preamp boards in the lab by the end of the year. They
have the same form-factor and pin-out as the original, so they can
go straight into the prototype detector and work right away.<br>
<br>
I will plan to fire up the prototype with the existing electronics
on the bench, and measure the pedestal lineshape to extract the
single-pixel response. I have a few things I wonder if you could
look up for me. <br>
<ol>
<li>the discriminator thresholds on all of the SiPM 8 signals
(chan. 0-4, 12-14). If they changed, the date/times when they
were changed.</li>
<li>the gain setting (adc chan/mV) on each channel in the FADC.<br>
</li>
</ol>
Knowing these things will help me cross-check all of my assumptions
that I used in extracting the number 350 pixels from the adc
spectra. I agree that the detected pixel count is an important
thing to make sure we got right.<br>
<br>
Let's plan to review these results at one of our biweekly meetings
and assess what risks still exist in our design, which may be
reduced by a second run in Hall B in 2012.<br>
<br>
-Richard Jones<br>
<br>
On 11/3/2011 9:34 AM, Alexander Somov wrote:
<blockquote type="cite" cite="mid:Pine.LNX.4.64.1111030928050.6795@jlabl1.jlab.org">
<pre wrap="">Hello Richard,
Yes, I agree. I think that once we confirmed the
amount of light in the scintillator fiber, the
rest of tests can be done on the test bench.
( though if you get some part of the detector ready
by spring, we can test it with the beam again -
I volunteer to help with the tests..., but again,
it's up to you )
Cheers,
Alex
</pre>
</blockquote>
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