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Dear Christina,<br>
<br>
Based on the measurements by David and Tara, we approve the Bcal
First article samples you sent us. The two issues that we discussed
earlier, which need modification for the production units, are 1)
the length of the cable connecting the Bcal boards should be
increased by 5 cm. 2) input connector with bias and trigger lines
should be moved from its present location to the middle of the board
to avoid interference with the screws to attach the top plate.<br>
<br>
Thank you for your patience. Sincerely, Elton.<br>
<br>
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<th align="RIGHT" nowrap="nowrap" valign="BASELINE">Subject: </th>
<td>Re: OK for Monitoring boards</td>
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<th align="RIGHT" nowrap="nowrap" valign="BASELINE">Date: </th>
<td>Tue, 5 Jun 2012 10:37:53 -0600</td>
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<th align="RIGHT" nowrap="nowrap" valign="BASELINE">From: </th>
<td>Zisis Papandreou <a class="moz-txt-link-rfc2396E" href="mailto:zisis@uregina.ca"><zisis@uregina.ca></a></td>
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<th align="RIGHT" nowrap="nowrap" valign="BASELINE">To: </th>
<td>David Lawrence <a class="moz-txt-link-rfc2396E" href="mailto:davidl@jlab.org"><davidl@jlab.org></a></td>
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<th align="RIGHT" nowrap="nowrap" valign="BASELINE">CC: </th>
<td>Elton Smith <a class="moz-txt-link-rfc2396E" href="mailto:elton@jlab.org"><elton@jlab.org></a>, Christina Kourkoumeli
<a class="moz-txt-link-rfc2396E" href="mailto:hkourkou@phys.uoa.gr"><hkourkou@phys.uoa.gr></a>, Tara Bogart
<a class="moz-txt-link-rfc2396E" href="mailto:tara.bogart.10@cnu.edu"><tara.bogart.10@cnu.edu></a>, Andrei Semenov
<a class="moz-txt-link-rfc2396E" href="mailto:semenov@jlab.org"><semenov@jlab.org></a></td>
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<pre>Hi Elton:
from what Tara and David showed today (slide 3) the far:near is 3:1, although with the manual bias setting the SiPMs were powered in 1 V intervals (i.e. 74 or 75 V but nothing in-between). This should not affect the conclusion that the devices are working as expected. And these tests are at room temperature.
David, Andrei and I will work on a run plan of what to do next, including computer control of SiPM bias, varying LED bias and trigger frequency, and temperature tests as well as cosmics.
For now though, please look over the presentation and if it looks ok to you too, grant the green light for the LED procurement. Christina is at CERN so she can start pushing the process through.
Cheers, Zisis...
On 2012-06-05, at 9:18 AM, David Lawrence wrote:
> Hi Elton,
>
> Hopefully, you've been able to have a look at the slides I pointed you to in the previous e-mail. These were shown at the Calorimetry meeting today. There was some question remaining on the JLab approval for board production. From what we have seen, all of the LEDs and SiPMs look to be firing. The LED signal amplitude is easily adjustable via the Vbias. Are there any additional tests you'd like to see done prior to production? If not, I think they are just waiting for word from you.
>
> <a class="moz-txt-link-freetext" href="https://halldweb1.jlab.org/wiki/images/4/4c/20120605_miniBCAL_bogart.pdf">https://halldweb1.jlab.org/wiki/images/4/4c/20120605_miniBCAL_bogart.pdf</a>
>
> Regards,
> -David
---
Prof. Zisis Papandreou, Ph.D., P.Phys.
Department of Physics | tel.: (306) 585-5379
University of Regina | fax.: (306) 585-5659
Regina, SK S4S 0A2 | email: <a class="moz-txt-link-abbreviated" href="mailto:zisis@uregina.ca">zisis@uregina.ca</a>
Web: <a class="moz-txt-link-freetext" href="http://web.me.com/zisis/professional/">http://web.me.com/zisis/professional/</a>
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