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Hi Stepan,<br>
<br>
The only way to keep the window inflated is to flow gas. We could
switch to N2 to maintain sufficient pressure to maintain window
shape. But, that may result in an increase is gas C4F10 loss during
during N2 flow operation and again during the later "topping off"
process. Since we have not done this before, there is no reference
to point to. It does add an additional layer of complexity to the
activity.<br>
<br>
George<br>
<br>
<div class="moz-cite-prefix">On 3/9/2018 2:54 PM, Stepan Stepanyan
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:1FE0E147-0E44-4CEE-A25A-ED770A3B590C@jlab.org">
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George,
<div class=""><br class="">
</div>
<div class="">Thanks for the details. Yes, it seems not much can
be saved, but anything we can save is a plus. </div>
<div class="">Of course we cannot allow window come down on
mirrors. In that respect, is there a option to reduce the loss?</div>
<div class=""><br class="">
</div>
<div class="">Regards, Stepan</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
<div>
<blockquote type="cite" class="">
<div class="">On Mar 9, 2018, at 2:23 PM, George Jacobs <<a
href="mailto:jacobsg@jlab.org" class=""
moz-do-not-send="true">jacobsg@jlab.org</a>> wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
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charset=windows-1252" class="">
<div text="#000000" bgcolor="#FFFFFF" class=""> Ho Mauri,<br
class="">
<br class="">
An additional 2 weeks of running will result in a
decrease of ~7 kg gas from the supply tank, assuming
0.5kg per day usage.<br class="">
<br class="">
Currently, ~56 kg C4F10 remains in the supply tank. This
is a 112 day supply assuming 0.5 kg per day usage.<br
class="">
<br class="">
So, if we do nothing, in 2 weeks there will be ~49 kg
C4F10 remaining in the tank. No change in detector
pressure. Same as now.<br class="">
<br class="">
If we do turn it off, there will be ~56 kg remaining in
the tank when we restart flow. Detector pressure and
fill will be reduced due to gas leakage and the loss
from ambient pressure changes during the outage. The
detector will need to be "topped off" once we turn the
gas back on. This will require X amount of gas. Since X
is unknown, but most likely X < 7 kg and most
definitely X > 0, the amount of gas saved will
definitely be < 7kg. So, we do not know how much gas
this will actually save. Once gas flow is restarted, it
may require 1-2 days to refill. My only real concern is
if the window deflates to the point were it contacts and
applies pressure to the mirrors. That would be bad<br
class="">
<br class="">
I do not see much of a savings or advantage in turning
it off. But, that's not my call, it's yours. We can turn
gas flow off if you want it off. Let me know what you
decide. We will need to turn the gas off at the supply
tank.<br class="">
<br class="">
Cheers,<br class="">
George<br class="">
<br class="">
<div class="moz-cite-prefix">On 3/9/2018 11:03 AM,
Maurizio Ungaro wrote:<br class="">
</div>
<blockquote type="cite"
cite="mid:0094C616-BF59-40A8-A414-65928169E57C@jlab.org"
class="">
<pre class="" wrap="">Hi George,
We'll have a downtime in accelerator that may run for a couple of weeks.
In the spirit of saving as much gas as possible, what are our options?
Thanks,
Mauri
</pre>
</blockquote>
<br class="">
<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" moz-do-not-send="true">jacobsg@jlab.org</a>
(website) <a class="moz-txt-link-freetext" href="https://userweb.jlab.org/%7Ejacobsg" moz-do-not-send="true">https://userweb.jlab.org/~jacobsg</a></pre>
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</blockquote>
</div>
<br class="">
</div>
</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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