[BTeam] Lebedev's beam scrapers

[Michael Tiefenback]

These were, as I recall, late in the injection chicane, roughly 0R07 in the 6 GeV layout and near the inline dump.  They were only occasionally useful.  They had to be upstream from the first BLA cavity, else they would have reduced the potential transmission from end of injection chicane to our metered users.

Michael Tiefenback

________________________________
From: BTeam <bteam-bounces at jlab.org> on behalf of Jay Benesch <benesch at jlab.org>
Sent: Monday, August 22, 2022 20:03
To: Joe Grames <grames at jlab.org>; BTeam <bteam at jlab.org>
Subject: Re: [BTeam] Lebedev's beam scrapers

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
> _______________________________________________
> BTeam mailing list
> BTeam at jlab.org
> https://mailman.jlab.org/mailman/listinfo/bteam
> <https://mailman.jlab.org/mailman/listinfo/bteam>

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________________________________
From: BTeam <bteam-bounces at jlab.org> on behalf of Jay Benesch <benesch at jlab.org>
Sent: Monday, August 22, 2022 20:03
To: Joe Grames <grames at jlab.org>; BTeam <bteam at jlab.org>
Subject: Re: [BTeam] Lebedev's beam scrapers

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
> _______________________________________________
> BTeam mailing list
> BTeam at jlab.org
> https://mailman.jlab.org/mailman/listinfo/bteam
> <https://mailman.jlab.org/mailman/listinfo/bteam>

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