Dave, i'm happy you looked into it, awesome stuff really.
Actually i don't understood what you mean by negative side of the coil, i guess what will happen is that the ions will align in the middle of the tube axial "without touching the walls like" and right in the position of equilibrium which is exactly the center of a solenoid or in a toroid anywhere inside the toroid..
thats because in a toroidal field there is no field "traveling outside" so there is no middle. I think it need to be DC for this but i'm not sure
This magnetic bottles are used to confine charged particles and even anti-matter.
I don't know why but i found a similarity with the EPG i thought with spheric magnets inside and an idea i had a long time ago, which i called the vibration transformer, would be an arrangement of 3 magnets two fixed at the sides repelling a center magnet as to make it free to move... Than the idea was to wind a primary and secondary coil around it and ad a capacitor in series with the primary and pulse it with low voltage... the idea was to drive it at the frequency of the harmonic mechanical oscillation of the magnets... I guessed at the time that it could possibly show some strange effects, but i wasn't able to construct it, with the knowledge i had. At least with this setup much could be learned from.
I meant this because there is an EPG where the gas don't need to flow inside...