Talk:Quadrupole magnet
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[edit] F vs D quadrupole orientation
The description of them and their difference doesn't make a lot of sense as written unless one already understands the material...I don't think just a link to Maxwell suffices here. Let's say there are N poles positioned at 0° and 180° and S poles at 90° and 270° (relative to an observer looking along the direction of the beam). What directions are focusing, and what directions are defocusing (for some given sign of the particle charge)? The confusion is that it feels like a C<cub>4 axis--every 90° one is at the same position relative to "an opposing pair of poles". DMacks 02:41, 3 March 2006 (UTC)
Shouldn't the arrows on the animation at the bottom swap around with the poles?Grj23 (talk) 16:11, 31 March 2008 (UTC)
- Oh yeah, good point. Don't know off-hand how to fix it though. I don't have an animated GIF editor.- (User) WolfKeeper (Talk) 16:24, 31 March 2008 (UTC)
In terms of the description of the focusing and defocusing, wouldn't it be helpful to refer to the F=ev x B type formula (or whatever it is). I think that would be clearer (assuming I've understood what's going on!). I think this was quite helpful though Grj23 (talk) 16:11, 31 March 2008 (UTC)

