What do you plan to contain the plasma in? If it touches a vessel it
will cool off or melt the vessel. If you are thinking about magetic
containment, forget it. It has been tried for 60 years and it does not work.

Bob Kolker

If you use a gas burner, or a flame thrower like that one, how will you
keep from burning up the balloon?

Man, your sense of proportions by no means helps, but then you can
watch this video to see that the flame from the burner on a typical hot
air balloon shoot more 6 feet.  That doesn't prevent control.