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Dear all, and in particular RG-C SPOKESPERSONS, <font color="#ff2600" class=""><b class="">ESPECIALLY THOSE INTERESTED IN KAONS</b></font>,
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<div class="">while we had a great rally to repair and install LTCC in all sectors (2,3,5,6) not occupied by RICH in time for RG-C, two of these sectors (2 and 6) have now developed significant leaks (see below), to the point where we can NOT complete the run
while keeping them filled the entire remaining 8 months.</div>
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<div class="">For this reason, at today’s RG-C RC meeting, we decided to empty sectors 2 and 6 for now to preserve C4F10 gas. (Yes, sometimes important decisions ARE being made at these meetings). The reasoning is that this first part of the run with FTOn configuration
is mostly dedicated to DVCS, where Kaons are not as important. Once we switch to ELMO / FTout, we can reassess and fill at least one of them again for the rest of the run, or both (until we run out of gas). Just a heads-up - let me know if you have any comments.</div>
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<div class="">Greetings - Sebastian
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<blockquote type="cite" class="">I have tracked the leak rate of the LTCC system since they were filled in early June. At the current leak rate of ~ 25 kg per month for 4 detectors, we will be out of gas in 6 months.<br class="">
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Sector 2 leaks about 11 kg per month,<br class="">
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Sector 6 leaks about 8 kg per month,<br class="">
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Sectors 3 and 5 each leak about 3 kg per month.<br class="">
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New C4F10 is currently unavailable. We may be able to order some on a long lead time and high expense. For reference, we purchased 500 kg in 2018 for $67.5K ($135/kg). This was existing inventory at the time and they notified us that the price of future
purchases would be much higher.<br class="">
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Therefore, we should consider when all 4 detectors are needed and when we can empty sector 2, and possibly sector 6. If we empty sector 2 and leave it empty for the entire run, the gas will last approximately 10 months. I do need access to the Hall for a
short time to empty a detector.<br class="">
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I would like to discuss this at the RC meeting today at noon.<br class="">
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Thanks,<br class="">
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Bob<br class="">
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