Check this out.

[LightningGSX]

There a lot of math that I don't really understand, but here's what I make of it.First, in general, this is "just barely" fusion.Most of the ions either miss each other in the center and turn around to make a another trip towards the center, where they'll probably miss again.And alot hit the electrode, so what it amounts to, is very few ions actually fuse.Also, by nature of the design, considerable more electrons have to go into it(uses more power), than ions it can accelerate.Considering that, and the fact most of the ions don't fuse, it will always consume much more energy than it can produce from fusion.Finally, fusion produces neutrons, which can't be contained by IEC because of their neutral charge, so most of the fusion energy is radiated away.Their only real commercial purpose is as a neutron source