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Thank you for all the reply and the good information, these things will help. </div>
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-Brian</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> mhattawy@odu.edu <mohammad.hattawy@gmail.com><br>
<b>Sent:</b> Friday, August 28, 2020 9:57 AM<br>
<b>To:</b> Sebastian Kuhn <kuhn@jlab.org>; Bob Miller <rmiller@jlab.org>; David Hamlette <hamlette@jlab.org>; Eugene Pasyuk <pasyuk@jlab.org><br>
<b>Cc:</b> Brian Freeman <bfreeman@jlab.org>; Michael Tiefenback <tiefen@jlab.org>; Dennis Turner <dturner@jlab.org>; HyeKyoung Park <hkpark@jlab.org>; bteam@jlab.org <bteam@jlab.org>; Stepan Stepanyan <stepanya@jlab.org>; Paul Vasilauskis <vasilaus@jlab.org><br>
<b>Subject:</b> Re: [BTeam] [EXTERNAL] Follow up on Hall B Halo Rates Troubleshooting</font>
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<div>Hello all, <br>
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<div> David Hamlette surveyed the upstream beam pipe, around 9 AM, and did not find any hot spot. The beam has gone at 5:00 AM, so maybe the 4 hours down time did kill all the activation. Bob Miller is in the Hall to cycle the other valve, VBF2H01A, and check
the beamline components once more for any displacement. <br>
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<div>Mohammad. <br>
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<div dir="ltr" class="x_gmail_attr">On Fri, Aug 28, 2020 at 9:28 AM Sebastian Kuhn <<a href="mailto:kuhn@jlab.org">kuhn@jlab.org</a>> wrote:<br>
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<div style="">Just a small addition: We have already tried re-centering the beam on the target structure - TWICE - and also changing the angle with which it comes into the Hall. Nothing changed the background, and we could not find any obstructions other than
the known target walls, which we avoid by centering the beam.
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<div>- Sebastian<br>
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<div>On Aug 28, 2020, at 6:01 AM, Brian Freeman <<a href="mailto:bfreeman@jlab.org" target="_blank">bfreeman@jlab.org</a>> wrote:</div>
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<li>We could simply try angle and position changes into the target ? It looks like things got really noisy after a target change in the hall on the 15th, probably a coincidence (<a href="https://logbooks.jlab.org/entry/3835820" id="x_gmail-m_7452309039069088108LPlnk901337" target="_blank">https://logbooks.jlab.org/entry/3835820</a>)
. I believe that the Midstream counters sit around the Target somewhere, and Downstream counters are after CLAS. So perhaps we just have a bad angle going into the Target? ( 1hr )</li></ol>
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<div dir="ltr" class="x_gmail_signature">Best regards,<br>
Mohammad Hattawy.<br>
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