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Hi all - <br>
<br>
Please see Jay's comments on whether to start at 4 or 5 pass. It sounds like he supports having Hall C start at 4th pass.<br>
<br>
Cheers,<br>
Dave
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<th valign="BASELINE" align="RIGHT" nowrap="nowrap">Subject: </th>
<td>Re: starting pass for higher current running in Hall C</td>
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<th valign="BASELINE" align="RIGHT" nowrap="nowrap">Date: </th>
<td>Thu, 3 Jul 2025 09:28:15 -0400</td>
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<th valign="BASELINE" align="RIGHT" nowrap="nowrap">From: </th>
<td>Jay Benesch <a class="moz-txt-link-rfc2396E" href="mailto:benesch@jlab.org"><benesch@jlab.org></a></td>
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<th valign="BASELINE" align="RIGHT" nowrap="nowrap">To: </th>
<td>Dave Gaskell <a class="moz-txt-link-rfc2396E" href="mailto:gaskelld@jlab.org">
<gaskelld@jlab.org></a></td>
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<th valign="BASELINE" align="RIGHT" nowrap="nowrap">CC: </th>
<td>Mark Kevin Jones <a class="moz-txt-link-rfc2396E" href="mailto:jones@jlab.org">
<jones@jlab.org></a></td>
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<br>
<br>
Dave,<br>
<br>
The present schedules has C switching to fourth, back to fifth, and then to fourth again. Since A isn't taking fourth, there's no longer any reason for that sequence. As you write it makes sense to take Hall C to fourth pass first and get the RF under control
at 780 kW, assuming 25 uA to A and 60 uA to C, and then try for 1000 kW. 23 days at fourth pass followed by 24 days at fifth pass with only two pass changes is probably the way to go.<br>
<br>
The Hall C run certificate and RSAD have 60 uA maximum currents so the 80 uA on fourth pass in Doug's latest schedule is not allowed.<br>
<br>
Decide and relay to Doug.<br>
<br>
Jay<br>
<br>
On 7/3/25 08:21, Dave Gaskell wrote:<br>
<blockquote type="cite">Hi Jay -<br>
<br>
In our experiment planning meeting yesterday for the upcoming higher<br>
current running, we were discussing whether to start at 4 or 5 pass. I<br>
don't think there's any significant reason for the experiment to favor<br>
starting at one or the other. I was thinking, though, that it might be<br>
easier to transition to the higher current running at 4 pass instead of<br>
5. There would be less total current in the machine, and then there<br>
would be time to gradually optimize before we went to 5 pass, the more<br>
challenging condition.<br>
<br>
What do you think?<br>
<br>
Cheers,<br>
Dave<br>
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<br>
<br>
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