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If you look in the logbooks from last night, the beam got stuck in 1L after changing the energy. Much steering was required to get the beam into 1R</div>
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<a href="https://logbooks.jlab.org/entry/3896169">https://logbooks.jlab.org/entry/3896169</a><br>
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The message is that we do produce significant radiation in Tune mode when steering the machine. Is anyone surprised by this?</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> BTeam <bteam-bounces@jlab.org> on behalf of Jay Benesch <benesch@jlab.org><br>
<b>Sent:</b> Tuesday, August 24, 2021 6:41 AM<br>
<b>To:</b> BTeam <bteam@jlab.org><br>
<b>Subject:</b> [BTeam] large radiation readings during 980 setup</font>
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<div class="PlainText">In the few minutes since I first read this I haven't come up with
<br>
anything actionable, which is why I didn't send it to mcc_ops.<br>
<br>
<a href="https://logbooks.jlab.org/entry/3896176">https://logbooks.jlab.org/entry/3896176</a> by Pavel Degtiarenko<br>
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The 7A15 detector is operational, further troubleshooting is not needed. <br>
All NDX detectors are live and produce signals now. Few photon channels <br>
are noisier than others, not critical for the neutron measurements in <br>
normal conditions.<br>
Illustrations to the beam losses during beam recovery are shown in the <br>
attachments. Observed signals at 1L08, 1S01, and 7A15.<br>
The beam first produced spiked dose rates at 1L08, at the levels ~550 <br>
R/h photons, ~90 rem/h neutrons.<br>
Then for about 10 min intermittent dose rates at 1S01 at levels ~30 R/h <br>
photons, ~20 rem/h neutrons.<br>
Then a single spike at 1S01 at the level of ~230 R/h photons, ~70 rem/h <br>
neutrons.<br>
Then there was a photon flash at 7A15 at 20:49:05, very short, even not <br>
registered in the beam current PV, at the level of about 1 kR/h photons, <br>
and no neutrons. The currents in the photon and neutron ICs were about <br>
the same, and their weighted difference was corresponding to -1 rem/h <br>
neutrons, meaning that there was no neutrons during that flash. The <br>
illustration to the limitations of the method: can't measure neutrons if <br>
their dose rate level is about or below ~1/1000 of that of photons'.<br>
Then at 21:04:45 there was a "normal" beam loss around the Arc 7A15, <br>
with the dose rates about 16 R/h photons, and 11 rem/h neutrons, for a <br>
couple minutes.<br>
<br>
<a href="http://devweb.acc.jlab.org/CSUEApps/atlis/view_attachment.php?attachment_id=14980">http://devweb.acc.jlab.org/CSUEApps/atlis/view_attachment.php?attachment_id=14980</a><br>
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<a href="http://devweb.acc.jlab.org/CSUEApps/atlis/view_attachment.php?attachment_id=14981">http://devweb.acc.jlab.org/CSUEApps/atlis/view_attachment.php?attachment_id=14981</a><br>
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