[BTeam] Lebedev's beam scrapers

[Jay Benesch]

Joe,

Thank you very much. I had forgotten that they were in the injector. 
I'm looking at things to put at 1+ GeV so scrapers designed for 45 MeV 
are not useful.

Jay

On 8/22/22 19:59, Joe Grames wrote:
> 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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