<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="">Hi Amrit,<div class=""><br class=""></div><div class="">Back of the envelope, 2 days at 100 liters / day would be only 3% of the volume. Perhaps we did not notice this.</div><div class=""><br class=""></div><div class="">We did eliminat several sources of leaks from the original box, where the leaks where on the same order of magnitude you mentioned. </div><div class="">New backwal, hermetical connectors, walls sealed form the inside, window better placed, nose sealed better.</div><div class=""><br class=""></div><div class="">In any case, my question remains: do we know where it is coming from? If it is the box perhaps we can improve the situation?</div><div class=""><br class=""></div><div class="">David did find more leaks after installation but he worked on those and minimized them until nothing was detectable with the freon detector anymore.</div><div class=""><br class=""></div><div class="">Thanks,</div><div class="">Mauri</div><div class=""><br class=""></div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Apr 26, 2017, at 3:11 PM, Amrit Yegneswaran <<a href="mailto:yeg@jlab.org" class="">yeg@jlab.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><div style="font-family: tahoma,new york,times,serif; font-size: 14pt; color: #009900" class=""><div class="">hi maurizio,<br class=""></div><div class="">these leakage rates are the measured rates while we are flowing N2.<br data-mce-bogus="1" class=""></div><div class="">assuming low leakage rates initially, we are driven to believe that in the process of installing, something happened.<br data-mce-bogus="1" class=""></div><div class="">also, since the leakage rate wasn't quantified, i don't see how you can say that these rates are an order of magnitude higher.<br data-mce-bogus="1" class=""></div><div class="">amrit<br data-mce-bogus="1" class=""></div><div class=""><br class=""></div><hr id="zwchr" data-marker="__DIVIDER__" class=""><div data-marker="__HEADERS__" class=""><b class="">From: </b>"Maurizio Ungaro" <<a href="mailto:ungaro@jlab.org" class="">ungaro@jlab.org</a>><br class=""><b class="">To: </b>"Amrit Yegneswaran" <<a href="mailto:yeg@jlab.org" class="">yeg@jlab.org</a>><br class=""><b class="">Cc: </b>"dsg-ltcc" <<a href="mailto:dsg-ltcc@jlab.org" class="">dsg-ltcc@jlab.org</a>>, "Patrizia Rossi" <<a href="mailto:rossi@jlab.org" class="">rossi@jlab.org</a>>, "David Anderson" <<a href="mailto:dla@jlab.org" class="">dla@jlab.org</a>><br class=""><b class="">Sent: </b>Wednesday, April 26, 2017 2:57:41 PM<br class=""><b class="">Subject: </b>Re: [Dsg-ltcc] ltcc leakage rates.<br class=""></div><div class=""><br class=""></div><div data-marker="__QUOTED_TEXT__" class="">Hi Amrit,<div class=""><br class=""></div><div class="">These rates are rather big. Where do they come from? </div><div class="">David took many precautions to ensure the box was tight. We didn't quantify it but I would gess the remaining leaks we had were order of magnitudes below these.</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">Thanks,</div><div class=""><br class=""></div><div class="">Mauri</div><div class=""><br class=""><div class=""><blockquote class=""><div class="">On Apr 26, 2017, at 2:52 PM, Amrit Yegneswaran <<a href="mailto:yeg@jlab.org" class="" target="_blank" data-mce-href="mailto:yeg@jlab.org">yeg@jlab.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><div style="font-family: tahoma,new york,times,serif; font-size: 14pt; color: #009900" class="" data-mce-style="font-family: tahoma,new york,times,serif; font-size: 14pt; color: #009900;"><div class="">brian, marc, and george measured the leakage rates of the ltcc sectors over an extended period of time.<br class=""></div><div class="">based on these measurements the results are</div><div class=""><table style="width: 253px; table-layout: fixed;" class="" data-mce-style="width: 253px; table-layout: fixed;" border="1px" cellpadding="3px"><tbody class=""><tr class=""><td style="text-align: center;" class="" data-mce-style="text-align: center;">sector <br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;"><div class="">C4F10</div><div class="">L/day<br class=""></div></td><td style="text-align: center;" class="" data-mce-style="text-align: center;">C4F10 kg/day<br class=""></td></tr><tr class=""><td style="text-align: center;" class="" data-mce-style="text-align: center;">1<br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;">95<br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;">1.06<br class=""></td></tr><tr class=""><td style="text-align: center;" class="" data-mce-style="text-align: center;"><span style="background-color: rgb(255, 255, 153);" class="" data-mce-style="background-color: #ffff99;">2</span><br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;"><span style="background-color: rgb(255, 255, 153);" class="" data-mce-style="background-color: #ffff99;">32</span><br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;"><span style="background-color: rgb(255, 255, 153);" class="" data-mce-style="background-color: #ffff99;">0.36</span><br class=""></td></tr><tr class=""><td style="text-align: center;" class="" data-mce-style="text-align: center;">3<br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;">118<br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;">1.32<br class=""></td></tr><tr class=""><td style="text-align: center;" class="" data-mce-style="text-align: center;"><span style="background-color: rgb(255, 255, 153);" class="" data-mce-style="background-color: #ffff99;">4</span><br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;"><span style="background-color: rgb(255, 255, 153);" class="" data-mce-style="background-color: #ffff99;">38</span><br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;"><span style="background-color: rgb(255, 255, 153);" class="" data-mce-style="background-color: #ffff99;">0.43</span><br class=""></td></tr><tr class=""><td style="text-align: center;" class="" data-mce-style="text-align: center;"><span style="background-color: rgb(255, 255, 153);" class="" data-mce-style="background-color: #ffff99;">5</span><br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;"><span style="background-color: rgb(255, 255, 153);" class="" data-mce-style="background-color: #ffff99;">27</span><br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;"><div class=""><span style="background-color: rgb(255, 255, 153);" class="" data-mce-style="background-color: #ffff99;">0.30 </span><br class=""></div></td></tr><tr class=""><td style="text-align: center;" class="" data-mce-style="text-align: center;">6<br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;">101<br class=""></td><td style="text-align: center;" class="" data-mce-style="text-align: center;"><div class="">1.13<br class=""></div></td></tr></tbody></table><br class=""></div><div class="">sectors 2, 4 and 5 are best.<br class=""></div><div class="">sectors 1, 3, and 6 are worst.<br class=""></div><div class=""><br class=""></div><div class="">as we have 155 kg of C4F10, and it takes 73 kg to fill a sector we could in principle use any of the sectors for a 30 day run period, e.g. engineering run.<br class=""></div><div class="">of-course best would be to select a sector from 2,4,and 5.<br class=""></div><div class=""><br class=""></div><div class=""><span style="color: rgb(255, 0, 0);" class="" data-mce-style="color: #ff0000;"><em class="">we advise against the removal of the good sectors (2,4, and 5), as it appears the leaks are caused during the process of installation and/or removal.</em></span><br class=""></div><div class=""><br class=""></div><div class="">for physics runs, if the RICH could be installed in sector 1 we could run run with sectors 2, 4, an 5 at a cost of:<br class=""></div><div class="">filling: 3*73kg =219kg -> cost = 219kg*170 $/kg = $37230.<br class=""></div><div class="">leakage(ops) : (0.36+0.43+0.30) 1.1kg/day -> cost 1.1kg/day*170 $/kg= 187$/day<br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div></div></div>_______________________________________________<br class="">Dsg-ltcc mailing list<br class=""><a href="mailto:Dsg-ltcc@jlab.org" class="" target="_blank" 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