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Please keep me (crew chief) posted on the plan to address optics today.</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Jay Benesch <benesch@jlab.org><br>
<b>Sent:</b> Friday, May 23, 2025 07:27<br>
<b>To:</b> Michael Merz <mmerz@jlab.org><br>
<b>Subject:</b> Fwd: B beam is blown. For that matter, the whole machine is blown.</font>
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-------- Forwarded Message --------<br>
Subject: Re: B beam is blown. For that matter, the whole machine is blown.<br>
Date: Fri, 23 May 2025 07:24:53 -0400<br>
From: Jay Benesch <benesch@jlab.org><br>
To: BTeam <bteam@jlab.org>, mmeuller@jlab.org<br>
<br>
More recent material<br>
<br>
Ops matched at 7E01 <a href="https://logbooks.jlab.org/entry/4381741">https://logbooks.jlab.org/entry/4381741</a><br>
harp traces post-match<br>
<a href="https://logbooks.jlab.org/entry/4381745">https://logbooks.jlab.org/entry/4381745</a> 7E01 A beam<br>
<a href="https://logbooks.jlab.org/entry/4381746">https://logbooks.jlab.org/entry/4381746</a> 7E01 B beam still big<br>
<a href="https://logbooks.jlab.org/entry/4381751">https://logbooks.jlab.org/entry/4381751</a> AE01 A beam<br>
<a href="https://logbooks.jlab.org/entry/4381755">https://logbooks.jlab.org/entry/4381755</a> AE01 B beam still big<br>
<a href="https://logbooks.jlab.org/entry/4381756">https://logbooks.jlab.org/entry/4381756</a> 2C05 X below design, Y 3x design<br>
<a href="https://logbooks.jlab.org/entry/4381753">https://logbooks.jlab.org/entry/4381753</a> Hall B now makes it to the
<br>
dumplette without tripping ILM7S/9S01!<br>
<br>
My recommendation to reduce the B laser spot to ~1.3 mm round still <br>
holds. I also recommend rematching Injector to NL YMMV<br>
<br>
On 5/23/25 07:16, Jay Benesch wrote:<br>
> Colleagues,<br>
> <br>
> A selection of elogs. Scan the logbook for a fuller picture.<br>
> <br>
> <a href="https://logbooks.jlab.org/entry/4380694">https://logbooks.jlab.org/entry/4380694</a> Yan's summary Wednesday<br>
> <a href="https://logbooks.jlab.org/entry/4381729">https://logbooks.jlab.org/entry/4381729</a> IHAAE01 with B beam<br>
> <a href="https://logbooks.jlab.org/entry/4381709">https://logbooks.jlab.org/entry/4381709</a> IHAAE01 with A beam<br>
> <a href="https://logbooks.jlab.org/entry/4380687">https://logbooks.jlab.org/entry/4380687</a> chopper scans - B beam widest<br>
> <a href="https://logbooks.jlab.org/entry/4380556">https://logbooks.jlab.org/entry/4380556</a> laser size measurements in pdf<br>
> <br>
> All values 4 sigma from pdf<br>
> A laser X 1.60 mm Y 1.61 mm<br>
> B laser X 1.92 mm Y 2.00 mm<br>
> C laser X 1.22 mm Y 1.27 mm<br>
> D laser X 1.27 mm Y 1.42 mm<br>
> <br>
> Joe told me that they allow a larger spot for B because of the narrow <br>
> slit. The slit constains the beam in the longitudinal dimension, not <br>
> transversely.<br>
> <br>
> I suggest the B laser spot be adjusted to match C and D, ~1.3 mm in both <br>
> planes, this morning.<br>
> <br>
> <a href="https://logbooks.jlab.org/entry/4381707">https://logbooks.jlab.org/entry/4381707</a> fopt results with half-kick.
<br>
> Scraping in AL and BL. No response on the first kick in either plane <br>
> implies to me that the injector-NL match is blown. The sensitivity to <br>
> MBL0R03 suggests the beta functions there are far larger than the design <br>
> (x,y) (19.1, 13.3) m.<br>
> <br>
> Jay<br>
<br>
<br>
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