2. Again, all technology is expensive in the beginning. Who cares? The important thing here is to climb magnitude by magnitude. NIF climbed many magnitudes in recent history, making it notable.
3. As you mentioned, Helion and direct energy capture. D+He3 + DEC might be not feasible with a tokamak, but the scaling laws of fusion (size, current, B field) are in favor of experiments that get close.
4. See 3
5. See 3
6. See 3
7: See 3
I think you have a very negative take on what is an amazing breakthrough accomplishment. Even if the NIF doesn't end up converting their research into a commercial powerplant, they have at least demonstrated experimental viability of inertial confinement fusion. It's only a matter of time before the next generation shows viability of D+He3 fusion and then we'll have even more options.
You may call it a "milestone" if you like, even though it is a milestone on the way to nowhere. The only reason fusion gets any attention is because megaton bombs worked, and already demonstrated Q>1.
People are building out solar and wind power systems that stand some chance of fending off climate catastrophe, each day pushing fusion, like fission, farther from any prospect of competitiveness.
The consequences of a breakthrough are often not noted at the time. It is only when the consequences have happened that we recognize them and grasp the change which has been catalyzed by the discovery. Who, other than Mathematicians, cared about Number Theory when it was discovered?
I don't know enough about plasma physics to characterize this one way or the other, but I think looking for notable consequences is very slippy ground to stand on when dismissing a result.
along with 1.3 million others [0]. just sayin'
[0] https://news.clearancejobs.com/2022/08/16/how-many-people-ha...
But that they don't hire anybody without still tells us something.
These sorts of hard questions about scaling it up into real life have been some of the most persuasive fusion critiques.
And the bit you tapped into about the whole detachment from the gov research world from making something they have to justify with hard $$ and all that comes with it are very legitimate.
Mostly Agreed: there may be applications such experimental astrophysics, but that's certainly not the main motivation.
> 2. It has no consequence for any civilian project. The target that produced a couple of MJ cost $10M. (2.4 MJ is <0.7 kWh.) A real plant would need to feed them in at a high rate. Q is not the important measure. Dollars out / dollars in is the right measure, and everyone is still at exactly zero, with no plausible prospect of ever exceeding 1.
The cost of just about anything new regarding fusion experiments is not very meaningful: likely it had to be invented, designed and manufactured just for them. Of course it's crazy expensive, but it doesn't mean prices won't go down after an industry around fusion has been established. Just look at the price of a c-Si solar cell in the 70s.
> 5. No research has gone into identifying a viable material, in decades, despite that none is known. After a short time the reactor parts would all become weak and (also) fiercely radioactive.
I don't know about inertial confinement, but in magnetic fusion that is completely false. Materials with low activation, radiation damage resistance and good plasma properties have been continuously researched for the last 30 years: the current candidate for ITER is EUROFER97 for which you can find almost 800 publications. [1]
> 5. Repairs would need robots not yet designed.
Also false. Not only there are several remote handling designs for DEMO power plants, but they have also existed for a long time. For example, JET had been operated remotely since 1997, during the DT1 campaign. [2]
> 6. Civil fusion would require a large amount of tritium, which no one knows how to make economically.
Well, this is dishonest. Of course no one knows how to breed tritium economically: we don't know what the economy will look like in 40-50 years, but we surely know how to do it.
Fusion power plants are designed for self-sufficiency, producing more tritium that they consume by a factor of at least 1.05 (called tritium breeding ratio). Very briefly, this involves a breeding blanket that converts lithium to tritium and a complex chemical plant to extracts newly produced tritium from the blanket and also recovers it from the unburnt plasma fraction. See [3] for an overview of various design that will be tested in ITER.
For as long as there are a few CANDU reactors around, the current tritium supply will be enough to bootstrap future fusion plants without expensive ad-hoc production. [4]
[1]: https://www.journals.elsevier.com/nuclear-materials-and-ener...
[2]: https://yewtu.be/watch?v=hg6MnjG7m6U
2. Robots for fuel handling in a JET reactor are as far from robots for fusion plant repair as a Sopwith Camel is from Artemis. All they share is the word "robot".
3. Nobody can suggest any way to separate, every day, a few grams of tritium at PPB concentration from a thousand tons of molten FLiBe and lead.
I worked as a control systems engineer in the nuclear power industry for 8 years back in the '90s. I worked on Lungmen in Taiwan, ABWRs (Kashiwazaki 6/7) and even Fukushima (power uprates) in Japan and Grand Gulf and Pilgrim in the USA.
Fusion is billed as a "clean" alternative to fission reactors but I think this is (another) false hope of the technology. I still recall my nuke prof telling me that fusion (if it ever works) is going to be an even bigger waste problem than fission reactors. The 15 MEV neutrons are going to neutron-activate tons of shielding or heat extracting blankets which would be a huge disposal problem. He also thought that neutron embrittlement of plant structures was going to be a serious problem and is already a problem in fission plant cores that use thermal neutrons. Carting that waste away at EOL will kill the economics.
We should start building fission plants now which are safe and clean enough and can provide power until something better comes along.
Fission is distinguished by being the most expensive power in current heavy use. All the nukes will be mothballed, soon enough, unable find takers at a price that would pay for continued operation.
1. It is, purely, bomb research dressed up as civilian activity for funding purposes. Everyone working on it has top-secret clearance.
2. It has no consequence for any civilian project. The target that produced a couple of MJ cost $10M. (2.4 MJ is <0.7 kWh.) A real plant would need to feed them in at a high rate. Q is not the important measure. Dollars out / dollars in is the right measure, and everyone is still at exactly zero, with no plausible prospect of ever exceeding 1.
3. Extracting useful energy would require capturing hot neutrons in a "blanket", heating it up, and running fluid through it to boil water to drive a steam turbine. The minimum practical size for such a "blanket" exceeds that of a large fission plant. To collect enough neutrons to be useful requires a huge volume of plasma, as even compressed plasma is very diffuse vs. fissiles.
4. Compressing the plasma with superconducting magnets could increase density, but then the neutron flux through the smaller surface area of the chamber wall would destroy it that much more quickly.
5. The hot neutron flux would also quickly weaken the structural parts required to contain the enormous forces exerted by the electromagnetic coils. Superconducting coils would impose even larger stresses. No research has gone into identifying a viable material, in decades, despite that none is known. After a short time the reactor parts would all become weak and (also) fiercely radioactive. Repairs would need robots not yet designed.
6. Civil fusion would require a large amount of tritium, which no one knows how to make economically.
7. Steam turbines cost a lot to operate, regardless of heat source. No other generation method relying on such steam turbines -- coal, fission, geo -- is today competitive vs. renewables. As the cost of renewables continues on down, they get less competitive by the day.
Fusion is intrinsically interesting, just not for power generation.
One company, Helion, is trying to make a fusion device that does not emit many hot neutrons. However, achieving conditions for this process, D-3He, is even harder than for D-T fusion. They hope to breed their own tritium, which would eventually decay to the 3He they actually need, but it is not clear how they will produce enough. (Fun fact, 3He loves to turn back into tritium.)
If they cannot, but they do get it working, it might end up usable for outer solar system exploration, which is difficult to power.
This "milestone" provides exactly zero meaningful information for the magnetic confinement fusion that is the only avenue being pursued for civil power.
Fusion offers no prospect of "unlimited free energy". It offers instead very expensive energy, or possibly none at all. We already have access to unlimited free energy, and need only build out the solar, wind, and maybe tidal systems to collect some as it goes by.