<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">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="">jacobsg@jlab.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">
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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 wrap="" class="">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
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</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">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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