Reply: The two cases are not really parallel. To step outside your house on a given day is something that you may or may not choose to do. But if nonbeing is a real possibility for you, then you are the kind of being that cannot last forever. In other words, the possibility of nonbeing must be built-in, "programmed," part of your very constitution, a necessary property. And if all being is like that, then how could anything still exist after the passage of an infinite time? For an infinite time is every bit as long as forever. So being must have what it takes to last forever, that is, to stay in existence for an infinite time. Therefore there must exist within the realm of being something that does not tend to go out of existence. And this sort of being, as Aquinas says, is called "necessary."
Inertial confinement is the use of rapidly imploding shell to heat and confine plasma. The shell is imploded using a direct laser blast (direct drive) or a secondary x-ray blast (indirect drive) or heavy ion beams. Theoretically, fusion using lasers would be done using tiny pellets of fuel that explode several times a second. To induce the explosion, the pellet must be compressed to about 30 times solid density with energetic beams. If direct drive is used—the beams are focused directly on the pellet—it can in principle be very efficient, but in practice is difficult to obtain the needed uniformity.  The alternative approach, indirect drive, uses beams to heat a shell, and then the shell radiates x-rays , which then implode the pellet. The beams are commonly laser beams, but heavy and light ion beams and electron beams have all been investigated.