Hold plasma into one spot with magnetic field?

[kevin_tee]

Hi, I curoius if there is any way to hold plasma into one spherical ball intead of donut as seen in tokamak using magnetic field? I have came up with a few design but it doesn't seem to do it.

Thank you.

 

[Drakkith]

The Polywell design does this to some extent. It's not exactly a sphere, but it's much closer than a doughnut.