[BTeam] Lebedev's beam scrapers

[Joe Grames]

Hi Jay,

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.

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.

Joe
________________________________
From: BTeam <bteam-bounces at jlab.org> on behalf of Jay Benesch <benesch at jlab.org>
Sent: Monday, August 22, 2022 4:09 PM
To: BTeam <bteam at jlab.org>
Subject: [BTeam] Lebedev's beam scrapers

Colleagues,

As a result of an email discussion I started about turning the DP
stations into collimators (high beta) and adding one at high dispersion
point, to clean up the beam, I got a question which reminded me of the
beam scrapers Valeri installed.  I can neither recall where they were
nor why they were removed.  Can anyone?

Jay
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