[FFA_CEBAF_Collab] [EXTERNAL] Re: re JLab/BNL FOA response

[Brooks, Stephen]

Also, in Jay's slides is there any reason why the rather complex 1.2GeV injector idea can't be replaced by the 650MeV single-loop injector throughout?  Is it because you wanted electrons and positrons simultaneously?  I don't see any disadvantage otherwise, unless you specifically wanted 1.2GeV.

     -Stephen

________________________________________
From: Brooks, Stephen <sbrooks at bnl.gov>
Sent: 07 March 2022 13:33
To: Jay Benesch; Georg Heinz Hoffstaetter
Cc: ffa at cebaf; Camille Ginsburg
Subject: Re: [FFA_CEBAF_Collab] [EXTERNAL] Re:  re JLab/BNL FOA response

Providing a dipole correction is in principle very easy with gradient magnets, since you can shift the magnet physically by a small distance.

18000 G.cm = 0.018 T.m = ~0.01 T Or less over the length of a typical CEBAF FFA magnet.  At 40T/m that's a 0.25mm shift.  I'm not 100% familiar but I think there are "piezo" movers that can be electrically operated to expand and contract over such small distances.  Although levers and gears and motors would be possible too...

I'm reminded that CBETA's windowframe correctors that wrapped around the magnets could provide something like 0.02T or 1280G.cm, equivalent to a 2mm shift of the whole magnet (!)  So that's another possibility.  And those correctors were only 10-15cm long, same as the magnets.  For CEBAF FFA, our magnets are order of 2m long.  The permanent magnet is transparent to the field from the windowframe outside.

     -Stephen

________________________________________
From: FFA_CEBAF_Collab <ffa_cebaf_collab-bounces at jlab.org> on behalf of Georg Heinz Hoffstaetter via FFA_CEBAF_Collab <ffa_cebaf_collab at jlab.org>
Sent: 07 March 2022 09:25
To: Jay Benesch
Cc: ffa at cebaf; Camille Ginsburg
Subject: [FFA_CEBAF_Collab] [EXTERNAL] Re:  re JLab/BNL FOA response

Hi Jay,

Is there space to put the correctors in-between the permanent magnets?

Best,
Georg


> On Mar 7, 2022, at 8:54 AM, Jay Benesch via FFA_CEBAF_Collab <ffa_cebaf_collab at jlab.org> wrote:
>
> Colleagues,
>
> I created the attached to clear up in my own mind what the options are.  This may assist in writing the FOA response.
>
> The last two slides may throw a large wrench into the whole exercise.
>
> Jay <FFA_options_benesch_7mar2022.pdf>_______________________________________________
> FFA_CEBAF_Collab mailing list
> FFA_CEBAF_Collab at jlab.org
> https://mailman.jlab.org/mailman/listinfo/ffa_cebaf_collab


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