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Hi Jay,</div>
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Arne removed two injector scrapers from CEBAF, and gave them to me. I modified and repurposed them into the peppo spectrometer, they defined the dp/p bite of the e+ spectrum. After peppo they were slightly radioactive, so they cooled off for awhile, then
were released by radcon and I've stored them in a cabinet or shelf since last ~decade.</div>
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I sort of recall Arne had them removed them b/c they generally weren't used, however there were some instances when one (or both?) were inadvertently inserted partially inserted, causing halo or beam loss, I forget which. As built, they are nominally ear-marked
for Amy's LDRD (if it's funded), to define the momentum of a degraded e- beam. I believe there are drawings of the original scrapers, might be less work to built to print then to unmodify what was done for peppo?, but glad to pull them out for inspection,
let me know.</div>
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Joe</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> Monday, August 22, 2022 4:09 PM<br>
<b>To:</b> BTeam <bteam@jlab.org><br>
<b>Subject:</b> [BTeam] Lebedev's beam scrapers</font>
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<div class="PlainText">Colleagues,<br>
<br>
As a result of an email discussion I started about turning the DP <br>
stations into collimators (high beta) and adding one at high dispersion <br>
point, to clean up the beam, I got a question which reminded me of the <br>
beam scrapers Valeri installed. I can neither recall where they were <br>
nor why they were removed. Can anyone?<br>
<br>
Jay<br>
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