Separator thoughts

Separator mass resolution is an engineering issue, not a beam dynamics issue.

Transmission is a beam physics issue.

After 9 years, we've never gotten close to the calculated resolution of 10,000. This is not because of anything intrinsically wrong with the separator.

We tune to get something like this:
(0.5mm by 12mrad)
taller one,
S-shaped one
Octupole movie
small emittance

But the high resolution design
was 0.13mm by 60mrad!:

Or, comparing on the same scale:

(N.B.: 120 mrad full width is
24 cm wide beam in dipole centre.)
the 2 on same scale

We've never even gotten close. Why not?

We did not finish the engineering:

slits not controllable to fractions of mm,
hall probe only good to .3 gauss (that's 1:5000 for A=24),
aberrations are bad because quad polarity is incorrect,
Insufficient intensity i.e. lack of an offline source
...

Why did we never carry out the good intentions?

Get the science out. Given a choice:

Beam now with some contamination, or
allow beam physicists a couple weeks to commission high resolution,

experimenters prefer option #1, and learn to deal with the impure beam in another way.

Can we set it up once and forget it? No. A high resolution tune is hard to maintain because it is very fussy/sensitive to everything.

So where's the rationale for a resolution 10,000 separator?

Rick Baartman

Last modified: Tue Jan 22 15:23:44 PST 2008

We tune to get something like this: (0.5mm by 12mrad) taller one, S-shaped one Octupole movie
But the high resolution design was 0.13mm by 60mrad!:
Or, comparing on the same scale: (N.B.: 120 mrad full width is 24 cm wide beam in dipole centre.)