Here's the paper http://sublevel21.tk/public_files/toroid_formation.pdf Problem is stability/range. It's not much use to shoot a plasma toroid at 1000km/sec if it only stays stable for 5 microseconds (that would be a 5 meter range). Slow moving ones can stay stable longer, but are...well...too slow to be useful as a weapon. And there's another flaw with them - gradient is more important than field strength for "frozen" magnetic field lines. Here: http://arxiv.org/abs/1208.2961 EDIT: Another paper: http://www-pub.iaea.org/mtcd/publications/pdf/csp_008c/pdf/exp4_14.pdf EDIT2: I should note Marauder's 1000km/sec is a kinetic energy play (not say an attempt to transfer heat energy). Particle beams and really fast bullets I think will work out much better.