I've watched both the 'Should Google Go Nuclear?' and Microsoft Research videos on this topic. Both are pretty good. The Google video has Bussard in it and wa

I've watched both the 'Should Google Go Nuclear?' and Microsoft Research videos on this topic. Both are pretty good. The Google video has Bussard in it and was made not long before he died. The Microsoft paper talks about, well a lot of things, but I recall one of the key research items was cusp confinement. The problem with using magnets to control a plasma is the plasma will reject the magnetic field as its density increases. The wiffle ball shape of the resulting plasma of the polywell allows the field lines to penetrate the plasma even at higher density.