[Fwd: Re: leftover permanent magnets]

[Elliott Wolin <wolin@jlab.org>]

-------- Original Message --------
Subject: Re: leftover permanent magnets
Date: Mon, 12 Jun 2000 15:29:29 -0500
From: Philip Martin <pmartin@fnal.gov>
Reply-To: pmartin@fnal.gov
Organization: Fermi National Accelerator Lab
To: Elliott Wolin <wolin@jlab.org>
CC: Bill Foster <gwf@fnal.gov>, James T Volk <volk@fnal.gov>
References: <39217BEF.50DED340@jlab.org>
<3921872E.EF5AD16C@fnal.gov><392A8CF8.2F0E5FB@jlab.org>
<392AA6BC.F24FD52B@fnal.gov><392AB960.CCC79453@jlab.org>
<392AC186.804D3619@fnal.gov><3937FE21.16E1CB2A@jlab.org>
<39381B71.6B116649@fnal.gov><393C0263.463F72FD@jlab.org>
<393FD601.57C96165@fnal.gov><39452949.A43DE2E9@jlab.org>

I'll make a couple of comments, but am also forwarding this to Bill Foster and
Jim
Volk (who ran the production factory) in case they want to add something or
correct
anything I have written.

If you want only three that's fine...the rest will just sit here.

Dis- & re-assembly:  not trivial without the right tooling.  There are large
magnetic forces holding the assembly together.  Increasing the field is not easy
either...these are about the strongest magnets we could design with the
strontium
ferrite.  Increasing the gap is essential a whole new design.   Yes, it would
probably be cheaper to start from scratch, although some of the parts (in
particular the bricks, the temperature compensation, and the pole tips, the sum
of
these being the more expensive parts) could be reused.

Yes, we have LOTS of other (electro) magnets around.  We "gave" (traded for
shielding steel) about two hundred Main Ring magnets to Los Alamos.  Some of the
more common ones are called
EPB - 10' long, 1.5" x 3" aperture, ~1500 A for peak field
B1  - 20' long,  1.5" x 5" aperture, ~ 5000 A "    "      "
B2 - 20' long, 2" x 4", ~ 5000 A   (also a few 10' versions)
6-3-120 - 10' long, 3" x 6" aperture, ~ 2000 A
4-4-30 - 30" long, 4" x 4" aperture, ~ 200 A, but only .6 T.
There are many other kinds of magnets with small quantities.  Mainly large
aperture.

Phil

Elliott Wolin wrote:

> Hi Phil,
>
> It seems like we could use 2 or 3 magnets, and we were wondering whether we
> should ask for all 5.  What could we do with the extra 1 or 2 besides keep them
> around as spares.
>
> Is it crazy to consider taking one of the magnets apart and reconfiguring it
> somehow?  Can one increase the field, make it shorter, or change the gap,
> assuming field quality isn't important (e.g. for sweeper magnets)?  Are they all
> glued together and impossible to dismantle?
>
> Would it be cheaper to start from scratch than modifying one of them?
>
> Any thoughts?
>
> We need other magnets, e.g. sweeper magnets to clean up our photon beam after
> collimation.  They don't have to be permanent magnets, of course.  But if a PDV
> could be modified...or do you have other kinds of magnets lying around we could
> get our hands on?
>
>                                 Sincerely,
>                                         Elliott
>
>
> ================================================================================
>
>    Help feed the hungry, one click at a time:  http://www.thehungersite.com
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