[RightWhale]

the spherical torus

Got a schematic diagram or verbal description of this? I'm okay up to the doughnut shape concept and even the twisted doughnut--cruller.

[Windcatcher]

Here's Princeton's homepage for the NSTX (National Spherical Torus Experiment):

http://www.pppl.gov/projects/pages/nstx.html

Basically a spherical torus is a sphere, with the center cut out. I'm not a fusion expert, but it seems that changing the aspect ratio makes it a lot more efficient--the ratio of magnetic field strength to plasma temperature/pressure is lower (you don't need as much energy to maintain the plasma pressure).