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<div class="moz-cite-prefix">Hi Tim,<br>
<br>
Great!<br>
<br>
Thanks and best regards,<br>
Fernando<br>
<br>
<br>
On 4/18/2014 12:43 PM, Timothy Whitlatch wrote:<br>
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<div style="font-family: arial,helvetica,sans-serif; font-size:
12pt; color: #000000">Hi Fernando,<br>
<br>
I believe the spacers will be fine. We can get them in many
thicknesses. When the hub is ready, we will bring it to you
along with the spacers and verify this assumption by attaching
the ST1s. The Hub should be ready by the end of next week.<br>
<br>
Cheers,<br>
<br>
<div><span name="x"></span>Tim Whitlatch<br>
Hall D Engineer<br>
Jefferson Lab<br>
12050 Jefferson Ave ste 402<br>
Newport News, Va 23606<br>
757-269-5087<span name="x"></span><br>
</div>
<br>
<hr id="zwchr">
<div
style="color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><b>From:
</b>"Fernando J Barbosa" <a class="moz-txt-link-rfc2396E" href="mailto:barbosa@jlab.org"><barbosa@jlab.org></a><br>
<b>To: </b><a class="moz-txt-link-abbreviated" href="mailto:halld-pid@jlab.org">halld-pid@jlab.org</a><br>
<b>Sent: </b>Friday, April 18, 2014 11:48:24 AM<br>
<b>Subject: </b>Re: [Halld-pid] Start Counter Meeting
Minutes, April 17, 2014<br>
<br>
Hi Mark,<br>
<br>
Maybe I missed something but the spacers were always part of
the design. <br>
The question, as I understood at the meeting, was whether the
spacers <br>
provided enough precision and uniformity during attachment of
the ST1s.<br>
<br>
Best regards,<br>
Fernando<br>
<br>
<br>
On 4/18/2014 11:42 AM, Mark Ito wrote:<br>
> Folks,<br>
><br>
> Please find the minutes below and at<br>
><br>
>
<a class="moz-txt-link-freetext" href="https://halldweb1.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_April_17,_2014#Minutes">https://halldweb1.jlab.org/wiki/index.php/GlueX_Start_Counter_Meeting,_April_17,_2014#Minutes</a><br>
><br>
> -- Mark<br>
>
___________________________________________________________________<br>
><br>
> GlueX Start Counter Meeting, April 17, 2014<br>
> Minutes<br>
><br>
> Present:<br>
> * FIU: Werner Boeglin, Eric Pooser<br>
> * JLab: Fernando Barbosa, Eugene Chudakov, Mark
Ito (chair)<br>
><br>
> Electronics<br>
><br>
> Fernando gave us a report.<br>
><br>
> All fabrication of ST-1, ST-2, and ST-3 boards is
done. The signal<br>
> split for ADC and TDC is now done on ST-3, not on
ST-2 as before. The<br>
> ST-3 testing is complete. The pre-testing (checking
SiPM connections,<br>
> etc.) of the ST-1s is done and the 10 ST-2s are
being tested now. That<br>
> should be done by tomorrow. After that the 30
channels on the ST-1s<br>
> will be tested with a laser in the dark box. Also a
test will be done<br>
> to measure the electronic component of time
resolution using the laser.<br>
> It has a 100 ps rise-time and negligible jitter.
This will be done with<br>
> a complete chain from ST-1 to ST-2 to ST-3 to
discriminator to TDC. A<br>
> diffuser is used so that all four SiPMs can be
illuminated. A set of a<br>
> few amplitudes will be measured, and both ADC-bound
and TDC-bound<br>
> signals will be looked at. All tests should be done
by the end of the<br>
> month.<br>
><br>
> On the mechanical side, there is a plan to do a test
fit of the<br>
> electronics on the aluminum support ring once that
becomes available.<br>
><br>
> When the items have been shipped to FIU, Nick
Sandoval will go down and<br>
> help to get the test set-up started. Fernando needs
about one month<br>
> notice to arrange travel.<br>
><br>
> We had a discussion on the scheme for making sure
that the ST-1 boards<br>
> do not short against the aluminum support ring.
[Added in press: this<br>
> discussion assumed that there is no allowance for
spacing washers in<br>
> the design. This turned out not to be the case; a 40
mil washer is<br>
> called out in the drawings. This rendered the
discussion moot.]<br>
><br>
> The group reminded Mark that we will not ship ADCs,
TDCs, or<br>
> discriminators to FIU for testing the detector
there. FIU will use<br>
> their existing read-out electronics. We will send an
MPOD and all<br>
> cables that connect the ST-2s to the ST-3. We
discussed how many signal<br>
> cables need to be shipped (those running from the
ST-3). We decided to<br>
> defer a decision on that.<br>
><br>
> We decided that we should do a test mechanical
assembly at JLab before<br>
> shipping the support structure to FIU, including as
much as is<br>
> practical: support ring to target support, ST-3 on
installation cart,<br>
> cables from ST-2 to ST-3, etc. The exact plan needs
to be worked out.<br>
><br>
> Schedule<br>
><br>
> Werner laid out a very rough schedule given what we
know now.<br>
> 1. scintillators arrive at FIU: mid-May<br>
> 2. scintillator testing and detector assembly done:
end of June<br>
> 3. Nick visit: early July<br>
> 4. testing done: end of July<br>
> 5. ship to JLab: mid-August<br>
><br>
> Assembly Jig<br>
><br>
> Eric presented the final design for the assembly
jig. See his slides<br>
> ([18]PDF, [19]Powerpoint) for details. Eric plans to
call Chuck Hutton<br>
> and discuss the design as well.<br>
><br>
> Progress at McNeal<br>
><br>
> [Added in press: Eric talked to Robert McNeal just
after the meeting<br>
> and sent in this report.]<br>
><br>
> All 50 paddles have been inspected and have passed
the initial QA<br>
> check. Machining of the paddles has not yet
commenced. They are waiting<br>
> for the machines to finish other jobs. However,
production should begin<br>
> within a week.<br>
><br>
> Robert quoted that the paddles will be shipped out
to FIU, no later<br>
> than 05/02/2014 which is right at the 4 week lead
time we were quoted.<br>
><br>
> Eric provided Robert with the most up to date
mechanical drawing of the<br>
> paddles. There were no substantial differences
between the two drawings<br>
> and this update will have no negative consequences.<br>
><br>
> Robert mentioned that they do quantify the final
dimensions of the<br>
> paddles after they are machined. This is done both
optically and by<br>
> machine. Standard operating procedure dictates that
they will only<br>
> measure approximately 8 of the 50 paddles. He is
willing to provide us<br>
> with this data. It is possible for them to inspect
all 50 paddles and<br>
> provide us with their associated measurements for a
minor inspection<br>
> fee initially estimated at $200.00. Further
discussions will be made<br>
> regarding whether we should purchase this inspection
data.<br>
><br>
> References<br>
><br>
> 18.
<a class="moz-txt-link-freetext" href="https://halldweb1.jlab.org/talks/2014-2Q/Finalized_Assembly_Jig.pdf">https://halldweb1.jlab.org/talks/2014-2Q/Finalized_Assembly_Jig.pdf</a><br>
> 19.
<a class="moz-txt-link-freetext" href="https://halldweb1.jlab.org/talks/2014-2Q/Finalized_Assembly_Jig.pptx">https://halldweb1.jlab.org/talks/2014-2Q/Finalized_Assembly_Jig.pptx</a><br>
><br>
<br>
<br>
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