[Sneap] magnet

[alan cooper]

Hi Guys,
Hope this finds you all well.
No, I hav'nt retired as yet although my inactivety here may have led 
some to that conclusion.

I am surveying our lab with the hope of improving alignment of beam 
lines and equipment.
In many areas of operation I am finding that the equipment is very 
forgiving of alignment errors up to 1mm (0.040") in 10 m (34 Ft) 
although, some experimenters are on their operational limit.
Our lab buildings have moved millimeters over the last 15 years and we 
have been compensating for this whenever we have had access to 
individual lines or equipment.
The result is that errors have built up in sections, between sections 
and particularly between buildings over that time. It is hoped that the 
current survey will lead to overall errors of up to 0.25 mm (0.010") 
which should be adequate for our purposes.

Now, a question, can anyone point me to a clear description of how a 
double focussing analysing magnet works. I am particularly interested in 
the effect of changing the beam entry point, angular and parallel 
displacement, with respect to the field. Say vector in vs vector out.

Thanks and regards, Al