Does this mean you can now build a hydrogen bomb without uranium or plutonium?
If not, why not?
If not, why not?
ICF is a good way of studying what happens inside a hydrogen bomb, but it is in no way imaginable how you could use it as a weapon in itself. At this point, you'd be much, much better off just firing the lasers at your target (though even that wouldn't achieve much, unless you target is kind enough to step in front of a highly sensitive, gigantic laser).
Edit: corrected a typo graciously pointed out by GP.
Maybe if you can't fathom the precision required to irradiate the NIF hohlraum sufficiently isotropically to achieve ignition in the first place, you shouldn't be trying to answer this question.
The same thing that stops you from igniting the initial pellet with the hohlraum - you don't have anything creating the kind of confinement necessary to keep the plasma together.
The only thing allowing the plasma to get hot enough for fusion is the initial velocity of the inward-spreading shockwave from the initial explosion of the outer shell of the pellet. As the velocity of this shockwave inevitably decreases, confinement is inevitably lost and the plasma dissipates and cools down.
Probably in principle you could use the energy of the first pellet's plasma to cause similar shockwaves in a second, larger pellet and so on, but that requires an entirely different geometry, its not just a matter of putting the second pellet close to the first one.
There may be an engineering method to overcome this, but it would be way beyond the difficulty of getting that first pellet to ignite, which already is a bleeding edge technological development.
Between the primary fission bomb and the secondary fusion bomb there is a huge shield, so the shockwave of the first one hit's the second one at the same time everywhere, instead of hitting the top.
My guess is that to put a ternary fusion bomb you will need another even bigger shield, but IANANBS.
Nuclear fission of unstable isotopes is self-sustaining chain reaction that converts a lot of matter into energy without much of hardware - just put some sub-critical mass of Plutonium into a sphere lined with conventional explosives.
You don't even need explosives to get a self-sustaining nuclear fission chain reaction if you don't want a bomb; Harry Daghlian did it accidentally, Fermi did it underneath Stagg Field in Chicago in 01942, we do it routinely to generate electricity, and 16 fossil natural nuclear fission reactors have been discovered in Oklo. The explosives are only there to keep a rapid chain reaction from driving the pieces apart before you get enough yield for a weapon.
It's true that the NIF would not make a very useful bomb, being difficult to deliver to enemy territory even by ship, and probably inflicting more damage on the funding agency than the destroyed enemy city. But a significant part of that is non-recurring engineering costs, and it's probably possible to miniaturize it to a significant degree.
I read Freeman Dyson's autobiography recently, and he claims (contrary to the report of continuing DOE research in the Wikipedia article) one of the things they stopped working on in the 01960s due to the arms treaties was specifically hydrogen bombs that didn't require fission igniters.
Not ahcieving ignition means that the plasma cools too rapidly and the fusion reaction stops even before the brief microseconds of inertial confinement are lost.
Perhaps if you could deliver enough energy to a large enough pellet, you could use this to build a bomb, but today it is far too small for that, and the reaction wouldn't work with a larger fuel pellet (the geometry that allows the extreme pressures needed for fusion would not be easily achieved with a larger pellet, since even the wave-length of the laser is relevant at this level).