Yeah, I should have qualified that answer; for all practical purposes, you can’t (currently) significantly attenuate a magnetic field that would be intense enough to deflect coronal charged particles. (This depends on how large you build the field, of course; a very large, low flux density field would be easier to shield than a small, high density field, but then you’d have to build a much larger apparatus to control the field.) And you have the difficulty of powering the field, unless you have some highly compact superconducting magnets, so in practice spacecraft designers talk in terms of using physical shielding, especially water or hydrogen embedded in some matrix.
Now, if we could just dig up a few magnetic monopoles…
Stranger