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Comment by frellus | Hacker News Reader

I hate to ask this, but have to ... is there any danger of these discoveries being weaponized easily by hostile countries? i.e. does this make unconventional weapons more accessible to countries who otherwise have embargoes on technology and material to make atomic weapons?

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A process which has been finally accomplished at one of the most advanced research facilities in the world after decades of effort, and which requires as an energy input almost as much energy as the process produces, is not easily weaponized, no.

Fusion reactions are hard to start. To use one as a weapon would require you to deliver the fusion fuel together with a source of enough energy to start the fusion reaction off. So the most effective way to do so has historically been to trigger them with a nuclear fission reaction from an atomic bomb - which results in a Hydrogen bomb.

In other words, weaponizing fusion generally requires you to already have an extremely powerful weapon.

Weaponizing this laser based inertial confinement fusion approach requires you to deliver a facility the size of the Lawrence Livermore lab plus the electricity generating capacity of a significant part of the west coast of America onto your target.

> is there any danger of these discoveries being weaponized

Any advance in energy production or propulsion has a weapons counterpart.

Fusion bombs (H bombs) have existed for a long time.

> Fusion bombs (H bombs) have existed for a long time.

and their yield can be made arbitrarily large with designs perfected in the 50s. I don't see this tech contributing to weapons. ...well maybe the lasers i guess but not the fusion at least.

I'm not an expert (I'm a physics prof who once took a seminar on nuclear arms control back in college), but what they're trying to do here is much, much harder than making an atomic bomb. If you want nuclear weapons, this work on carefully controlled and contained fusion is close to the opposite of what you'd need to do. (Fusion power is in general much cleaner than fission, at least where lasting radioactivity and waste are concerned.)

Fusion bombs (H-bombs) were functional in 1952

Like a fusion reactor can be used as a neutron source to effectively make a breeder reactor.

However, most countries can dig up rocks out of the ground with radioactive isotopes that can act as a neutron source. However, this has legitimate uses as well from research to medical imagining. Also any power generating reactor is gonna want to use those neutrons to make Tritium otherwise it would quickly run out fuel so not something you just want use on something unrelated to running the fusion reactor.

Oops, answered my own question I guess:

https://en.wikipedia.org/wiki/Pure_fusion_weapon

That ain't good. Although fusion is clearly the future of energy, we have to get our sh*t together on earth so we don't kill ourselves off or devolve with endless wars. Or give up and use fusion to leave the planet efficiently.

So.. we attack our enemies by building large fusion power plants in their countries, and then blowing them up? Why not just build a traditional nuclear fission power plant and blow that up? It seems that would be a lot cheaper.

From your wiki source:

> The power densities needed to ignite a fusion reaction still seem attainable only with the aid of a fission explosion, or with large apparatus such as powerful lasers like those at the National Ignition Facility, the Sandia Z-pinch machine, or various magnetic tokamaks. Regardless of any claimed advantages of pure fusion weapons, building those weapons does not appear to be feasible using currently available technologies

Nothing about this result from NIF seems to suggest that igniting fusion is any easier than previously suspected.

> That ain't good.

Your takeaway does not match that article. The article details how "no measurable success was ever achieved" and that the large amount of energy required to start fusion is hugely prohibitive.

I don't see how the NIF's success here changes that.

I don't see how this is any different to mutually assured destruction via nuclear weapons.

We already have tens of thousands of nuclear weapons spread across the planet, with only two ever actually being aimed at anyone. Lots of problems but the threat of weapons at this scale are a well-feared thing already.

You have to remember that all of the classified details about US hydrogen bomb designs we have were leaked from leaked from Russia after the Soviet Union broke apart. And yet only two countries have managed to become nuclear states since then (Pakistan and North Korea).

It's the engineering that makes nuclear weapons hard to do, not the knowledge.

There are much simpler ways to generate fissile material for dirty bombs. This technology doesn't seem to be weaponisable in any other way that I can tell.

from my layman understanding I believe fusion reactions are unlike fission reactions in that if they escape the confines of their environment they fizzle out as opposed to runaway like a nuclear explosion.

The short answer is no.

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