Magnetic Geometry and the Confinement of Electrically Conducting Plasmas
  We develop an effective field theory approach to inspect the electromagnetic interactions in an electrically neutral plasma, with an equal number of negative and positive charge carriers. We argue that the static equilibrium configurations within the plasma are topologically stable solitons, that describe knotted and linked fluxtubes of helical magnetic fields. 
Ludvig Faddeev and Antti J. Niemi