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Hi Amrit,<br>
<br>
For the RICH N2 test to make any sense, the leak rate out of the
detector volume must be reduced. The leak rate was 100% of the gas
at 0.05 inches water column pressure. Detector pressure was unable
to increase to the point that the bubbler is set at, 0.1" wc. Simply
flowing gas without attending to the leaks does not solve the
problem.<br>
<br>
George<br>
<br>
<div class="moz-cite-prefix">On 10/29/2017 2:17 PM, Amrit
Yegneswaran wrote:<br>
</div>
<blockquote type="cite"
cite="mid:132310729.2173821.1509301064925.JavaMail.zimbra@jlab.org">
<div style="font-family: tahoma,new york,times,serif; font-size:
14pt; color: #009900">
<div>hello george, marc, and brian.<br>
</div>
<div>i trust we have another liquid N2 dewar, if not, <em>first
thing monday morning, connect the RICH system to the gas
cylinders</em> that i asked marc to procure. </div>
<div>There should be 10 N2 cylinders and 5 UHP cylinders.<br
data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>I guess there must be way to check how much liquid N2 is in
a dewar.<br data-mce-bogus="1">
</div>
<div>we should do that, and keep a log.<br data-mce-bogus="1">
</div>
<div>we have run out of gas on many occasions.<br
data-mce-bogus="1">
</div>
<div>my count is three times so far this year (another couple of
months to go!).<br data-mce-bogus="1">
</div>
<div>amrit<br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div>anecdotally, i still can recall my grandma, who never went
to school, from whom i learned how to look beyond the horizon
and into people's soul, telling me when i was in school: "on
any given matter: if you are smart you won't make the mistake,
if you are average you'll make it once. so amrit, what do you
call those who make the mistake over and over, hmm?" </div>
<div>I thought about it for a beat and replied "you are right,
the principal must be really dumb, he has caned me so often!"<br
data-mce-bogus="1">
</div>
<div>i guess repeating the same the same thing doesn't make me
bright!<span id="transmark" style="display: none; width: 0px;
height: 0px;"></span><br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div><br data-mce-bogus="1">
</div>
<div><br>
</div>
<hr id="zwchr" data-marker="__DIVIDER__">
<div data-marker="__HEADERS__"><b>From: </b>"Marco Mirazita"
<a class="moz-txt-link-rfc2396E" href="mailto:Marco.Mirazita@lnf.infn.it"><Marco.Mirazita@lnf.infn.it></a><br>
<b>To: </b>"dsg-rich" <a class="moz-txt-link-rfc2396E" href="mailto:dsg-rich@jlab.org"><dsg-rich@jlab.org></a><br>
<b>Sent: </b>Sunday, October 29, 2017 12:11:24 PM<br>
<b>Subject: </b>[Dsg-rich] Nitrogen test in the RICH<br>
</div>
<div><br>
</div>
<div data-marker="__QUOTED_TEXT__">Hi all,<br>
the N2 system in the RICH run for most of the weekend.<br>
The system was started at 13:50 on Friday with two lines
feeding 24 slm <br>
each.<br>
The initial humidity was about 37%, then started to drop quite
rapidly.<br>
We reached a minimum level of about 2% at 4:30 am on Saturday
night, <br>
then started to slowly increase because of the reduction in
the N2 flow <br>
due to the dewar that was almost empty.<br>
At 10 am on Sunday the flow was about 1.5 slm and the humidity
was about <br>
9%.<br>
See the elog entry <a class="moz-txt-link-freetext" href="https://logbooks.jlab.org/entry/3490201">https://logbooks.jlab.org/entry/3490201</a> and
<br>
<a class="moz-txt-link-freetext" href="https://logbooks.jlab.org/entry/3490246">https://logbooks.jlab.org/entry/3490246</a> for more details.<br>
<br>
The plan for next week is to restore the system as soon as
possible, <br>
then fill again the RICH and run for some time at the nominal
flow level <br>
of about 20 slm total.<br>
To do this a new dewar is necessary.<br>
<br>
Best regards,<br>
Marco<br>
<br>
<br>
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</div>
<br>
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</blockquote>
<br>
<pre class="moz-signature" cols="72">--
George Jacobs
Jefferson Lab (TJNAF)
STE 12
12000 Jefferson Ave.
Newport News, VA 23606
(office) 757-269-7115
(cell) 757-876-0480
(email) <a class="moz-txt-link-abbreviated" href="mailto:jacobsg@jlab.org">jacobsg@jlab.org</a>
(website) <a class="moz-txt-link-freetext" href="https://userweb.jlab.org/~jacobsg">https://userweb.jlab.org/~jacobsg</a></pre>
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