I have heard that the use of a longitudinally slotted, tubular conductor can reduce or eliminate polloidal eddy currents.
Taking the example of a short length of copper tube with a thin slot down its entire length, does the eddy current simply disappear or is it redirected as another force vector?
Have not got my coffee and am not thinking yet, so I can't think about why.
I use Litz wire to stop (reduce) eddy currents. (Litz wire is like stranded wire but each strand is insulated)
Any thing you can do to reduce the cross section of the copper works. I think slots will work.