Like I've said before. This has nothing to do with fusion, cold or otherwise. It's focused millimeter microwaves used to drill very deep holes.

Sad to say, from my research, I'm forced to conclude that with foreseeable technology spaceships will be restricted to a minimium size. Radiation is space is a real hazard beyond low earth orbit. To minimimize the health risks a lot of shielding will be required. By a lot I mean...bunchatons, like hollow out an asteroid and live inside it.