US Department of Energy: Fusion Ignition Achieved
energy.gov
energy.gov
Yesterday, everyone was complaining about the 2.2:2.0 ratio, but now we're working with 3.15:2.05.
With modern lasers, that'd be a total Q of 0.375 assuming 100% efficiency through direct-energy-capture.
The jumps to get here included
- 40% with the new targets
- 60% with magnetic confinement
- 35% with crycooling of the target
The recent NIF experiments have jumped up in power. The first shot that started this new chain of research was about 1.7 MJ of energy delivered. Now, 2.15 MJ. However, the output has jumped non-linearly, demonstrating the scaling laws at work.
> I’ve helped to secure the highest ever authorization of over $624 million this year in the National Defense Authorization Act for the ICF program to build on this amazing breakthrough.”
It's nice to see this milestone recognized, even if the funding it still rather small.
(And even then, it's dubious a laser fusion scheme will be competitive with other energy sources.)
The destination will be a milestone for humanity, so we should not give up.
A large, complex machine that explodes the equivalent of 500 lb. bombs to generate heat to drive a turbine sounds like an engineering nightmare.
It’s an incredible milestone, not a solved problem.
What’s the circle or not big milestone here?
Is this the right approach? Who knows. There are many fusion designs in the works, and those may ultimately be the right call. Or some yet-to-be-created design. That's even probable. The NIF is for simulating nuclear weapons, not creating energy. None of that takes away from this breakthrough - we've never had meaningfully more output than input on a repeatable basis. It's proof that contained fusion for energy isn't just hypothetical, which will also mean funding & interest will generally increase from this point on.
I think you're setting too high a bar. It's like saying no milestone should be celebrated until we have a working metropolitan-size plant running that's cheaper than anything else. Punch cards in the 1950s are insignificant compared to modern SSDs, yet they were an important step even though we don't use anything like it now. Breakthroughs are breakthroughs.
That is something personal and unique to each individual. In 1903 when the Wright brothers flew a heavier-than-air machine for 59 seconds, 99.99999% of the people on the planet wouldn't have cared. The airplanes you've flown on are vastly far removed from that original one. Same story for the point contact transistor in 1947. None of that solid state physics is used for modern transistors. Some people like to be early adopters for new ideas and things. Some don't. And that is OK.
I agree that the original press release flubbed the explanation. Here's how I think they should have presented it instead:
From https://www.nature.com/articles/d41586-022-04440-7
Herrmann acknowledges as much, saying that there are many steps on the path to laser fusion energy. “NIF was not designed to be efficient,” he says. “It was designed to be the biggest laser we could possibly build to give us the data we need for the [nuclear] stockpile research programme.”
How does "[It's big b]ecause sustainable positive energy out has never been achieved before in 60 years of research" translate to "because we say it's big" in your head?
You might not consider it big, but a specific reason was provided and it had zero similarity to your rephrasing.
is that because while the obstacles are grave, the consequences of failing to overcome them are much graver still,
and to the best of our collective knowledge,
industrial scale fusion would be the least bad answer to our energy demands for the next epoch.
That is true but also does not obviate the need for other parallel efforts and other technologies whose challenges are also very grave, e.g. the need for very near term very large scale carbon sequestration, for a modern electrical grid with deep redundancy and resilience, the need for effective safe scalable stores for energy from whatever source, etc.
Why is that? Fusion is not needed, although if it turned out to be cheap that would be nice.
Watt went around telling everyone that Trevithick and his compact (ie high pressure) steam engines were too dangerous and would never work.
Yes, some exploded. But then we got steam trains and even today almost all power generation on the planet is high pressure steam-electric power plants.
And using actual bombs and explosives to dig kilometers down and mine coal is not an engineering nightmare? Dying of gas in the mines, fires on oil wells, oil spills, these things are 'engineering simple'?
It's a fusion plasma research experiment. It's not a program that is being run with the goal of creating a usable fusion energy power plant.
What alternatives to petrolium does the US have that it does not rely on others for?
Those crazy sci-fi stories from the 30s and 50s where everyone used nuclear power (and it was so cheap they didn't bother to meter it) were all completely accurate from a non-political viewpoint
Why wouldn't a final Q of 50 be economically viable? Interest on capital costs? Other?
The targets are only expensive because they aren't produced at scale yet.
They are the exact kind of thing a machine could churn millions of per day out, and then use them at the same rate.
Even if the targets were made of expensive materials (eg. platinum), most of that platinum could later be recovered from the reactor wall, so it still wouldn't be very expensive.
And recovering comes for free?
Every step costs energy (or money).
There is no working design yet. It is waay too early to make any predictions about how scaling could reduce costs. Scaling can even increase costs, if it depletes limited resources like tritium.
Is there any calculation to this? What’s the cost of shot? Is there any limetime limit of the laser?
True if you want to replace base load of a civilization size network it needs to be economically viable, but we generate "a lot" of power at higher than market minima. Ironically, "good batteries" are the natural enemy of fusion research.
One fun thing about laser fusion is it theoretically can scale down very low and has a trivial "off" switch making it a good resource for engineering tokamak reactor materials or sensors or similar tasks.
The inner lining of a production fusion reactor is hard to make, so a laser facility would be ideal for research. Which is why we have one...
If you can process a tanker worth of hydrogen per second, Q can be just above break even and you will still make money.
The higher the Q, the lower throughput needed for feasibility.
How is it possible for X energy to create X+Y energy in output? Doesn't that violate some fundamental law of physics?
There's a threshold of energy required to attain this fusion reaction (otherwise there would be no light nuclei in the universe), and once the nuclei combine there's energy that is released, similar to how some chemical reactions can be exothermic in nature.
This is effectively what is happening with any energy generator.
Same principle, different means.
Fusion and fission are like that but for atoms instead of molecules.
But, O2 molecules, with their double bond, don’t take much energy to break apart. If they do, and then pair up with say a bunch of Hydrogen and Carbon atoms that were nearby in some long chain or something, they form bonds that are stronger - that take more energy to break - and you end up with some leftover energy. Water and CO2 molecules are an even lower energy configuration.
but the extra energy you get wasn’t exactly ‘in’ the oxygen bond though - any more than when you have a ball at the top of a hill it has potential energy ‘in’ it.
The original atoms (exactly which atoms depends on the reactor, but let's assume it's deuterium and tritium) have a certain starting energy. When you fuse them together the resulting atom (helium-4, if you start with deuterium and tritium) moves it into a lower energy state.
Since the fused atom has lower energy than the input atoms, the fusion reaction releases the difference in energy, which you can then capture.
When fusion happens, two hydrogen atoms fuse together into one, losing a bit of mass in the process. The mass difference is converted into energy Y (using E=mc2).
In this case, Y was greater than X, so there was a net gain in useful energy.
2.01410177811 u + 3.01604928 u = 5.03015105811 u
4.002602 u + 1.008 u = 5.010602 u
5.03015105811 u - 5.010602 u = 0.01954905811 u
Thank you.
These heaver-than-iron elements are created in a very interesting and exotic process. When a large enough star dies it explodes in a supernova, and a huge amount of energy and neutrons are released in a very short period of time. This supernova generates enough energy and neutron material that small amounts of heavier elements like gold, platinum, etc. are created through exotic nuclear fusion reactions, even though these heavy fusion reactions are energy-absorbing.
It's interesting to think when you're wearing jewelry made from gold or platinum, all of those atoms in your jewelry were created during the death of a star.
The conversion is also very slow. And expensive. To make it this way it would cost a Quadrillion dollars an ounce.
https://www.scientificamerican.com/article/fact-or-fiction-l...
Once you get past the enormous energy costs to do this you have a secondary problem, all the gold produced this way is radioactive and it beta decays to.. Mercury.
The wikipedia page is pretty good, as always: https://en.wikipedia.org/wiki/Nucleosynthesis
Almost everything with mass of 90 or above comes predominantly from neutron star mergers, basically.
I'd be interested to know if we're in an element rich vein of the wider universe or if all the good stuff is more or less evenly distributed?
>Some whole galaxies have average metallicities only 1/10 of the Sun's. Some new stars in our galaxy have more metals in them than the original solar nebula that birthed the Sun and the planets did. So the amount of "metals" like oxygen and carbon can vary by a few orders of magnitude from star to star, depending upon it's age and history.
https://www.reddit.com/r/askscience/comments/9tujxn/are_the_...
I have no idea, though, but I'm pretty sure I watched a video about this.
That kind of expansion rate has to rival any explosion imaginable.
"Stars are made of quarks"
https://static.wikia.nocookie.net/memoryalpha/images/d/d9/Qu...
star stuff = sternzeug. stern stoff = star fabric
https://www.ling.upenn.edu/~beatrice/110/docs/uncleftish_beh...
“The nitrogen in our DNA,
the calcium in our teeth,
the iron in our blood,
the carbon in our apple pies
were made in the interiors of collapsing stars.
We are made of star stuff”.
– Carl Sagan We have calcium in our bones,
iron in our veins,
carbon in our souls,
and nitrogen in our brains.
93 percent stardust,
with souls made of flames,
we are all just stars
that have people names"
Nikita GillBut not because “you are like a drop in the ocean,” but because “you are like an ocean in a drop.”
The idea of soul can be objectionable when it is based on an immortal being or on a vitalist life-force (like “anima” of the Latin). But it seems fine when it is based on the psyche (like the “Psuche” of the Greek).
I embrace taboo words like soul because they 1. are common 2. are useful for referring to things that seem pretty important (like avoiding soulless companies or products or buildings) and 3. are challenging to my normal (scientific) understanding of the world.
Still, I’d be more comfortable if the poem referred to the “carbon of our souls” rather than “carbon in our souls.” Hmm…
I think it might be an allusion to alchemy. Basically, the alchemists believed that ash (what was left after burning something) was the soul of all things...And-- this is where my complete lack of understanding about science shows-- I'm pretty sure Ash has lots of carbon? It's, you know, poetic. Many have claimed that poems are the "language of paradox" so it's okay for it to be a little non-literal. My interpretation of it, though, is that the soul is something impure that you must burn away, or maybe that the soul is polluted by our own words and behavior. It's definitely not meant to be scientifically accurate.
carbon's oxides are all gaseous at standard temperature and pressure
little carbon, then, not none
You and I are complicated but we're made of elements Like a box of paints that are mixed to make every shade They either combine to make a chemical compound or stand alone as they are
- They Might Be Giants
13.5 billion years seems like the time required to create a star, have the star die and blow up, have all that material settle and create a new star, then the planets are formed, than enough time on one of those planets needs to pass for life to form, then complicated life.
You raise an interesting question though: what is the earlier point of time where the heavy elements were abundant enough for life (as we know it) to form? Just because we started existing at +13.5 billion years, it doesn't mean carbon based life couldn't have formed much earlier.
Therefore, life could have developed in a few tens to few hundreds of millions of years after the big bang. That's still true even if we assume that heavier elements are created mainly when neutron stars collide and not by super/hypernovas as we theorized before LIGO/Virgo observatories.
Consequently, we likely are not a "progenitor" civilization in the universe if we only consider planets formation. We might not see anyone out there either because there's a great filter for intelligent life to emerge (so the bottleneck is in our past) or because few/no civilizations get to have an impact on their host stars (the filter is in our future) that would allow us to see them.
That being said, I wasn't aware of how LIGO changed the understanding of how heavier elements are usually formed, guessing it changed the expected neutron star prevalence? Do you have any additional reading on that?
Regarding the second point have a look at https://www.ligo.org/science/Publication-GW170817Kilonova/in... . That isn't my field of specialization, so I am not sure about recent publications. At the time though this was a big deal as kilonovas seem to be the primary source of heavy nuclei in the universe. That particular event crested between 1/100th to 1/1000th solar masses worth of heavy ( heavier than iron) nuclei. This is a greater rate than supernovas estimations.
It's not about the prevalence, but about the light curves observed during the event AT 2017gfo. They indicate significant heavy metal ejection but, what's interesting, also production.
> mergers of neutron stars contribute to rapid neutron capture (r-process) nucleosynthesis
These two articles cite the relevant papers:
https://en.wikipedia.org/wiki/GW170817#Scientific_importance
https://en.wikipedia.org/wiki/Nucleosynthesis#Neutron_star_c...
Maybe for a main sequence star, but there other processes that involve nucleosynthesis.
Iron will not happily fuse further because this NEEDS energy and where would that energy come from?
"heavier than iron" elements are produced when a star explodes because that collapse produces enormous amounts of energy.
During the collapse, the outer edge of the star is accelerated to something like 20% of the speed of light, that is an ENORMOUS amount of energy slamming down on the core.
Lastly, neutron starts don't produce energy, they are the incompressible remnants of a dead star.
He does an excellent job explaining things and put it to me like this.
Elements to the Left of Iron can undergo fusion and release energy, Elements to the right can undergo fission and release energy.
Iron IS the line because it needs energy to do either of these.
All elements want to find stability, and Iron is that Element because it needs energy for either fission or fusion.
So yes, Iron is the dividing line and this is what makes it so stable.
Edit: forgot to link the chart when referencing left or right..
(Yes I know it's technically mesons at the scale we're talking about but it doesn't rhyme so there)
-- Yeah there are a few alternative designs, but nothing that seems to do the division. https://en.wikipedia.org/wiki/Alternative_periodic_tables
And really, i guess everything is physics if you get specific enough.
>all the atoms in our universe/galaxy/solar system with a mass up to that of iron are formed in the core of stars
Roughly 90% of the helium atoms in the universe were created via Big Bang nucleosynthesis.
all is a strong word
for example: the nuclear fusion experiment in the article, that would have produced a few atoms heaver that hydrogen
(not to mention all the nuclear bombs that had a fusion stage)
So think about two stars killing each other to make your jewelry.
https://www.energy.gov/sites/default/files/styles/full_artic...
Which I'm going to watch, because even though everything I hear about this company gives me insane Theranos vibes... Well, if they pull it off... They might light a bulb with fusion in my lifetime.
(And I though I had seen a similar segment on "Answer with Joe", but I can't find it.)
None of those would be opposable source, of course - there won't be any until they open a plant, publish data, etc...
In the meantime, I see a hype cycle brewing, and it makes me a bit uncomfortable - but, we'll see.
2.01410177811 u = 3.34449439340696e-24 g deuterium
3.01604928 u = 5.008267217094e-24 g tritium
17.6 MeV = 7.832863e-19 kWh energy
Divide through, and you will see that you need 4.27 ug/kWh of deuterium, and 6.39 ug/kWh of tritium.
A random source [1] says that New York will use 50.6 TWh per year by 2027. That would require ~216 kg/yr of deuterium and ~323/yr kg of tritium.
This is all assuming 100% efficiency. A quick read suggests 50% efficiency might be practical, so double those quantities.
Also, i could easily have messed up that calculation somewhere, so please do check it!
[1] https://www.buildingcongress.com/advocacy-and-reports/report...
Tritium however is far more rare with only trace amounts of it being available within nature and barely more than a kg produced per year. Producing the 100s of kgs required per year still seems to be an unsolved problem, although my quick searching shows there's a couple viable solutions for it.
Though in practice enough will be lost that probably they'll still be somewhat net consumers-- just not nearly to the extent predicted by a simple thermodynamic model.
Still, even if fusion becomes a net producer of tritium, the whole tritium-is-hard-to-get problem will likely be a constraint that we'll be fighting as we ramp up use of fusion power in the future.
https://en.wikipedia.org/wiki/Tritium#Production
And there's not much of it:
> According to a 1996 report from Institute for Energy and Environmental Research on the US Department of Energy, only 225 kg (496 lb) of tritium had been produced in the United States from 1955 to 1996.[a] Since it continually decays into helium-3, the total amount remaining was about 75 kg (165 lb) at the time of the report.
Isn't that going to cause a serious problem if it requires 323Kg/yr of tritium just to power New York City?
[1] https://www.sciencedirect.com/topics/earth-and-planetary-sci...
I'm not sure how tokomaks are expected to work; do you just add lithium and expect the tritium to get where it needs to go to keep the reaction going, or do you actively remove gases from vessel, filter out the tritium, and re-use it as fuel?
Either way, I don't imagine it'd be too hard to recapture the stuff.
i.e. it's completely harmless unless you eat it.
They spent a few hours covered in dust on their coats, and did a bunch of subsurface skin damage which manifested as third degree burns. Sepsis, not radiation poisoning, generally killed them.
FWIW, tritium and a phosphor granule encapsulated in glass microspheres have been developed for self-illuminating runway paint, but again, no one really uses it because tritium is stupid expensive, and again, it' loses half its brightness in only a decade.
On the other hand, I've been told that Trijicon will replace their tritium gun sights for the lifetime of the original owner. I plan to live long enough to cost them money...
We'll all be using RDSs by then ;) ?
> ...I've been told that Trijicon will replace their tritium gun sights for the lifetime of the original owner.
I didn't know this, thanks.
> When I initially decided to write The Magic of Recluce in the late 1980s, I'd been writing science fiction exclusively... I conveyed a certain dismay about the lack of concern about economic, political, and technological infrastructures in various fantasies then being written and published in the field...
> I faced the very real problem of creating a magic system that was logical... Most fantasy epics have magic systems. Unfortunately, many of them, particularly those designed by beginning authors, aren't well thought out, or they're lifted whole from either traditional folklore or gaming systems and may not exactly apply to what the author has in mind.
> I began by thinking about some of the features and tropes of traditional fantasy. One aspect of both legend and folklore that stuck out was the use of "cold iron" to break faerie magic, even to burn the creatures of faerie, or to stand against sorcery. Why iron? Why not gold or silver or copper? Not surprisingly, I didn't find any answers in traditional folklore or even contemporary fantasy. Oh, there were more than a few examples, but no real explanations except the traditional ones along the lines of "that's just the way it works."
> For some reason, my mind went back to astronomy and astrophysics and the role that nuclear fusion has in creating a nova... Each of these fusion reactions creates a heavier element and releases energy... The proton-proton reaction that produces iron, however, is different, because it is an endothermic reaction...
> At the same time, the fact that metals such as copper or silver conducted heat and electrical energy suggested that they were certainly less than ideal for containing electrical energy. Gold and lead, while far heavier than iron, do not have iron's strength, and other metals are too rare and too hard to work, particularly in a low-tech society.
> At this point, I had a starting point for my magic system. I couldn't say exactly what spurred this revelation, but to me it certainly made sense. Iron can absorb a great amount of heat. If you don't think so, stand on an iron plate barefoot in the blazing sun or in the chill of winter. Heat is a form of energy. In fantasy, magic is a form of energy. Therefore, iron can absorb magic and, by doing so, bind it.
https://www.lemodesittjr.com/the-books/saga-recluce/recluce-...
I always thought this is the interesting takeaway, both fusion and fission funnel their constituent matter towards iron, as the final stable state of matter. Far future civilizations will have a lot of iron on their hands.
The law you're referring to might be the conservation of energy, but that applies to non-nuclear reactions and is more accurately called the law of conservation of mass-energy. In this case the energy in times the mass at the start is still equal to the energy out times the mass at the end. For the energy to increase, the mass must decrease to produce the Y in your equation.
The reason nuclear fusion is such a desirable goal is because it only takes a relatively small amount of mass to convert into a relatively large amount of useful energy, and the mass (the fuel) is relatively easy to obtain.
Like all energy generation, it's converting one type of energy into another, more convenient type, to do useful work. Like a hydroelectric dam converting the potential energy of water into more useful electrical energy. Energy is conserved when water spins a turbine, it's just that electrical energy is more useful for work than the potential energy of the water. Of course you can still use the potential (or kinetic) energy of the water directly, such as with a water mill. But the energy to work ratio is worse in that form (especially if the work to be done is far away from the watermill).
Whenever you build a fire you need to input some amount of energy to begin the chemical reaction that releases energy. In this instance we get not electrical energy, but energy in the form of infrared and visible light, to heat our home and light our way. Yet the total energy released by the fire far surpasses the energy you used to start the reaction, but because the wood's mass is consumed, energy is ultimately conserved. You have converted wood (not useful for heating your home) into infrared light (useful for heating your home).
Mass is energy at rest, hence equivalence with exception of massless particles like photons that have zero mass and non-zero energy. Also, photons travel with the speed of light in vacuum and cannot be found at rest in any frame of reference. Modern physics is fun, isn't it?
P.S. Neutrinos were thought to have zero mass as well, but according to the Standard model they have mass.
In a sense it's no more mysterious (conservation of energy-wise) than adding the energy of a spark results in the energy of the wood fire.
i.e. energy is transformed, not created as you quite accurately write.
the "extra" comes from the mass
because matter is energy, you can use conversion energy to turn matter into its stored energy.
Energy in total is still conserved, but it makes engineering sense to compare the size of the starting fire to the total inferno created.
I'm also a bit concerned that this type of research may encounter national security related obstacles. Obviously a pure fusion bomb would be a game changer for nuclear (non-)proliferation.
Suggest "Ripple: An Investigation of the World’s Most Advanced High-Yield Thermonuclear Weapon Design" from the Journal of Cold War studies to read about a predominantly fusion device family.
That could be carbon-copied to a fusion power plant, and indeed, there are many proposals of hybrid fusion-fission plants in the literature that only require Q values marginally greater than 1. But if you go that route, you have radiation just like a fission plant, and one starts to question why you don't just build a fission plant (indeed, why don't we?).
My personal pet theory of the future is that, one day, we'll progress so far in fusion research that we get economic energy. But at the same time, the line blurs between both fission and weapons technology, so people are unhappy with the result. This doesn't feel particularly contrarian but no one ever seems to bring it up.
Wikipedia: "Fast fission of the tamper and radiation case is the main contribution to the total yield and is the dominant process that produces radioactive fission product fallout."
However it’s possible to have higher fusion ratios at the expense of a larger device for the same yield. Most notably in the case of the Tsar Bomba’s which reduced the contribution of fission and too massively reduce the amount of fallout produced.
I'm not in any way saying that using lasers would be a plausible route to such a weapon, since the NIF facility is huge, but if it turns out that the research needs to focus on how to get more output per shot, which I think it inevitably would since a typical conventional or nuclear power plant generates on the order of 1 GW thermal power (To match that with a 1 Hz repetition rate, likely a stretch for a MJ class laser, you would need to generate 1 GJ per shot, comparable to the energy in a ton of TNT.), it would probably be touching on areas that are highly classified.
Basically it's a twist on the ice-9 solution to the paradox.
This is probably a bad thing; politicians might decide the bombs are clean enough to use.
I don't know enough about the Hafnium controversy to comment on it.
The key thing here is the Lasers aren't doing the immediate compression, the lasers are simulating X-Ray radiation which then is ablating the casing around the tritium. Figuring out how to create and amplify a x-ray pulse was a major sticking point in the Star Wars program.
The history of thermonuclear weapons leads me to think that the answer may be yes. There does not seem to be any real upper limit to how large a thermonuclear weapon can be made. In the 50's and/or 60's there were proposals to build GT devices. I don't think the fission trigger for such a weapon could have scaled by nearly as much.
So by analogy if a relatively small fission trigger can cause a fusion explosion that is many orders of magnitudes larger maybe one or more tiny laser induced fusion reactions could be used to trigger a much larger one.
If that were the case the efficiency of the laser trigger would be of little importance.
> "had to put 500 megajoules of energy into the lasers to then send 1.8 megajoules to the target - so even though they got 2.5 megajoules out, that's still far less than the energy they originally needed for the lasers," says Tony Roulstone of the University of Cambridge.
But it's good to finally see progress. Very few technologies can transform the world the way a practical fusion reactor could.
Good to hear that there's a laser design that might achieve that.
So the NIF is supposed to give a testbed to study implosion created fusion reactions that produce enough energy to "ignite", that is, propegate the reaction to the rest of a hypothetical bomb. In that case, the amount of energy needed for the infrastructure to produce the initial implosion doesn't matter, what matters is that the energy coming out is more then the actual energy that triggered the reaction, so that the hypothetical bomb would blow up and not fizzle.
Not even ask questions, not something like "hey, I saw this tweet, I know it's just a tweet, but can someone help me understand context?", no, you actually go ahead and criticize work that you know nothing about, and when confronted, you double down.
On some level, you must know yourself that it might be better to ask as many unloaded questions as you want, but otherwise sit this one out in terms of assessment.
I get that people are emotional about this, but it’s important to treat science with a critical eye.
The claim is that more energy came out than was put in. This is false.
It’s not just me saying it. https://www.tiktok.com/t/ZTRVP5Pmg/
There is no “context” to understand. Yes, it’s an impressive feat. Yes, other laser designs might fix the huge ignition costs. But that hasn’t happened yet, and until it does, it’s completely fair to point that out.
Will it win me any friends? Probably not. It’s like showing up to a party and saying the reason for the party is mistaken. Very few people care.
But scientists should, and I am one. Doubly so for incorrect reporting to laymen. We have a responsibility to convey what was actually achieved, not what we wish was achieved.
They are using inefficient lasers because they are cheaper to buy/maintain/modify for research purposes.
Determining the conditions for positive Q_plasma is largely a matter of science/research so the external system doesn't matter as long as the variables are controlled and results are reproducible.
Once positive Q_plasma is well understood/reproducible, achieving positive Q_total (more energy produced than spent running the infrastructure) is just a matter of engineering and potentially waiting for the SOTA for components (like lasers or materials) to catch up.
TLDR: This is the scientists proving the theory. Now it's the scientists' job to refine the theory. Then the engineers get to put it into production.
There will be no production, except of new, smaller thermonuclear warheads. That is their legislated remit.
No one (except perhaps poor science "reporters") is claiming that this means we now have free and cheap fusion power. Of course the energy put in to operate the lasers themselves needs to be accounted for -- and it is! -- but that doesn't make what they've achieved useless. It's also useful to remember that the researchers involved are not the people writing press releases and articles; let's not minimize their achievement just because of sloppy, sensationalist reporting.
I like the analogy downthread of a kid being excited about scoring a home run in baseball, but the dad chastising the kid for celebrating before actually winning the game. That's what it feels like is happening here.
This is a huge step in the right direction, and it should be celebrated as such.
a typical power price at trading hubs is US$40 per megawatt hour, though this varies considerably depending on many factors and is sometimes actually negative
a typical retail price is US$120 per megawatt hour
so this is about US$10 worth of electrical energy
Upgrading the lasers would slow the project down as new hardware is installed and issues are worked out. Not to mention I doubt the new hardware is cheap, and may be more expensive than burning excess energy using old laser tech in the meantime.
Other research groups work on laser efficiency, and the "final product" using this method (if it ever proves viable) would put together all the best pieces to get the best efficiencies.
You don't need to use efficient lasers to get the scientific results they're after - other people have already very accurately measured the properties of modern lasers, so we can predict how they would perform without having to actually use them.
300 megajoules was used to generate the laser (this is also captured in [1]). They also mentioned that newer lasers have 20% wall plug efficiency. If so, they need to improve the energy output by 5x in order to break even relative to wall plug energy consumption.
[1] https://techcrunch.com/2022/12/13/world-record-fusion-experi...
I don’t know why but this caused me to picture Alec from Tech Connections in a few years time, showing off his fusion laser plugged in to a kill-a—watt, while he explains carefully, through the magic of buying two of them, why you can get more power out than you put in, and why these old inertial confinement fusors were pretty neat actually.
This is big news but fusion will largely be a product of the people it attracts. The people can do the job attracting money and other talent if it's justified.
I've seen the Canadian gov try to throw money at trying to build a local tech scene and it all went to hucksters, old school finance suits with megacorp resumes, and administrators. While all the tech talent just kept going to SF where the capital was going into high risk ventures... not expensive buildings, events, 'entrepreneur/small business programs', and propping up old school D-round investors. Money is easily wasted even when the pursuit sounds noble and valuable on the surface.
The softer the bed linen, the more rested the computer scientists will be and the more likely they are to come up with novel solutions that lead to faster computing.
I think what other commentors may be getting at is that in many cases the simple analogy of asking how 9 women can have a baby in 1 month is instructive here. You could throw trillions at that problem, a need to have a baby in 1 month. Sometimes there are hard limits that money has a hard time addressing.
A case could be made that with enough money put towards advanced technology, like gene therapy to force a fetus to maturity in 1 month vs 9, it could be done with horrendous side effects.
So to your point money does solve all problems, but I think diminishing returns is putting it very lightly.
It's largely the same reason why NASA takes so long to do anything.
1. Shortage of funding
2. failure can result in loss/exhaustion of funding
3. extremely low risk tolerance
4. physical experiments needing new HW only happen when the likelihood of success is extremely high
5. projects are over engineered to reduce chance of failure
6. projects are over budget and over schedule
7. projects only make minor incremental progress
8. lack of fast/exciting progress drives decrease in funding
9. GOTO 1
NASA just isn't about high-risk / high-reward "moonshots" anymore. The overarching political environment doesn't allow it, never mind the office politics.
NASA will get back to the moon using easily an order of magnitude more funding than it should have taken, with a launch system that costs an order of magnitude more money for each launch than it should. (almost two?)
You can't be swift and lean when you are given very limited, budgeted funding. You can't take risks or you risk putting people out of a job and killing the program.
That leads to an overly conservative culture that restricts any risk taking and over-engineers everything to the point failure is effectively impossible.
This slow movement, overly conservative, design by committee approach helps limit risk but it absolutely balloons costs in the long run and horrifically delays progress. Of course if they were a company they'd eventually run out of money but that's not really an option for gov orgs so when the overly conservative, limited run designs end up encountering production issues, the projects explode in cost with nearly no upper limit.
TLDR: The political climate is a direct consequence of the lack of budget and continued restriction of that budget only worsens the problem.
This is so hilarious wrong I don't even know where to start.
> but the politics of its funding doesn't allow that.
The post that you are agreeing with says that "funding" is not the reason for their plan.
Anywhere at all would be better than nowhere. I worked for a defense contractor for a few years, so I'm basing my comment on my experience there.
> The post that you are agreeing with says that "funding" is not the reason for their plan.
Not sure what you are saying here.
> NASA just isn't about high-risk / high-reward "moonshots" anymore. The overarching political environment doesn't allow it, never mind the office politics.
Why doesn't the political environment allow for it. What could happen. What could regulatory bodies do to NASA for taking a risk and failing. What sort of constricting change could political bodies do in such a situation.
Three astronauts were incinerated alive. That was when they started to take safety more seriously. Subsequent accidents have only reinforced this.
The entire point of my comment is that funding cuts happened. That is the reaction.
For another example from a different angle, the military has limitless supplies of funding but innovates even less than NASA.
Nasa develops nuclear reactors, landed on titan and has reached pluto. Spacex vehicle has never left the Earth-moon system.
They may not have the same accomplishments as NASA, but they're far from a "company that makes trucks".
"NASA makes precision scientific instruments and SpaceX makes precision scientific instruments that have higher tolerances with a higher focus on throughput, and there are rapidly diminishing returns in how much funding can be used to close the gap" is probably the right take if not as fun.
Which scientific instruments does SpaceX make? I have never heard of a single one.
In contrast, curiosity rover has dozens.
Like, come on. I get shitting on Musk is the cool new thing, but this is genuinely the case where SpaceX is doing cool things in space, and at an extremely fast pace. Get over yourself if you can’t see through your Musk hate and only see them as “a company that builds trucks”.
Also, spacex has launched outside of the earth-moon system. It was a roadster
- Their incentive is to optimize for political approval, which means spreading facilities among as many congressional districts as possible, which creates a ton of inefficiency from poor communication and the need to constantly ship things around
- Public approval is the goal and failure is the worst possible option, so things tend to be optimized to take as few engineering risks as possible and have huge amounts of bureaucracy to spread the blame for any possible failure
There's a reason why SpaceX started landing rockets with a fraction of the money that NASA spent on building ridiculous boondoggles.
Ummm.. I thought remote work was no less efficient?
Scientists also don't work for free. They arent mushrooms that grow by themselves
This seems like a gross mistake.
If we are going to avert a climate catastrophe we will need TW of power to "unburn" the carbon we put into the environment (ocean and atmosphere). Instead of barely hitting this target, we should over deliver since we are running out of wall-clock time.
Every project that meets a bar for feasibility, organizational/operational capabilities (if they dont have it, either fix it, or transfer design to capable team) should be given funding (50-100M). We should be dropping BILLIONS on this, if we can drop 50B+ on semiconductors we can do the same for fusion.
Money is fungible. Dropping $billions on this means not dropping those $billions on something that works already, works fantastically well, and would work even better with more money. We already know how to prevent (more) climate catastrophe. We just need to do more of it.
So, no. Each dollar diverted from building out solar to mining coal or fooling with nukes brings existential catastrophe nearer.
Surely if you have a non-satisfactory yield you shouldn't be building it. And that should be possible to estimate before we spend billions on it?
Fission reactors work really well and have been around for 50+ years. If we are going to go nuclear instead of renewable, we need to address the elephant in the room.
The elephant in the room is: why not just fission?
See https://www.iaea.org/bulletin/safety-in-fusion for more details
Let me put the question another way: suppose we get fusion that's equally as safe as fission like IAEA is saying here. Why would we switch to it if we were unwilling to switch to fission?
The entire reason why people are working on fusion IS the fact that it’s much much safer due to all of the key differences. That doesn’t mean there aren’t lessons from fission to transfer, just as lessons from ICE cars have gone to EVs.
My point stands though: we're not doing fusion at scale yet, so we'll see.
What is the difference between todays announcement and yesterdays ?
I thought we were just getting re-submitted headlines, but apparently this news is different than yesterday ?
People believed that X:Y was 2.2:2.0, but it's now 3.15:2.05.
The 10% EROI apparently wasn't impressive enough, it's now 54% EROI on paper (assuming less because of capture inefficiencies).
I'm no expert, but theoretically my understanding is that this ratio should scale along this same pattern for higher values of Y.
Before that, the only official word was that an announcement was coming, and all the info was unofficial leaks and rumors.
Just wait until the DoD figures out they can use this for some military application and it will get 100x funding overnight.
I'm not trying to correct you, but adding context for the weapons aspect.
It may surprise people, but the DOE is the government body that is responsible for nuclear weapons research in the US.
Peaceful ones too, probably.
Harnessing the energy in a controlled and sustainable fashion is what's hard.
"thermonuclear bomb, also called hydrogen bomb, or H-bomb, weapon whose enormous explosive power results from an uncontrolled self-sustaining chain reaction in which isotopes of hydrogen combine under extremely high temperatures to form helium in a process known as nuclear fusion."
It still very much is a fission weapon.
[0] https://www.atomicarchive.com/history/hydrogen-bomb/page-11....
It still very much is a fission weapon.
https://en.wikipedia.org/wiki/Thermonuclear_weapon
Only very large bombs, such as the Tsar Bomba (97% from fusion) ever where primarily fusion, and those are not in modern arsenals.
So far it hasn't proven to be viable, but time will tell.
One would think that one look at the sky would be enough to say that "hey this fusion thing scales pretty well".
While at it: I don't think the NIF approach will ever be applicable to commercial power generation on Earth. But I hope it will be one day applicable to a fusion-based rocket engine.
People are estimating how this result moves the equation for an overall system that is designed for power production. Most numbers I have seen still leave a theoretically optimal power plant producing around a 30% loss in power with this number.
From what I understand, a lot of the work from the past years has been trying to piece together geometries, pulse timing, stability, and quality of targets.
the unsolved issue with laser fusion (ICF) as an energy source is the fast degradation of high powered lasers. High powered beam degrades optics on it's path and those things are expensive. ITER has similar problem with superconducting magnets.
I do understand that with more focus things can happen faster but you can really only pour so much concrete per day. Hopeful that we can figure out "leaner" ways to get this done.
I would love to see progress on this stuff, just don't like the idea of betting on successive megaprojects in the age of "a website is hard".
Adding more funding will probably see more parallel projects as well, especially at major institutions
In the UK is 1 KWh is £0.34
So, this costs £28 in electricity to run this experiment. The experiment is a momentary thing.
Clearly there is now some work to, but now this is becoming an engineering problem of how to extend, sustain, and scale this process.
The NIF fired 368 shots in 2021:
https://lasers.llnl.gov/for-users/nif-target-shot-metrics
At $10 million per target that would cost $3.7 billion. The annual LLNL budget (which includes NIF) is only $2.8 billion:
https://www.llnl.gov/doing-business/economic-impact
As of 2004, the targets were reported to cost $2500 each:
The 2004 targets didn't work. Neither did the 368 shots in 2021. Maybe ones that work cost more?
Even $2500 for 1 kWh is rather steep.
Those are just two of the engineering problems. It'll be a while, and I doubt it will ever compete with solar, wind, and storage.
Maybe not on earth, but there are applications in deep space.
Even if we had no other goal than becoming an intergalactic species as soon as possible, we might still benefit from working on other things first.
When you have a bunch of people who know how to build nuclear bombs sitting around with nothing to do, you damn well keep them busy before another country finds them a job.
You seem to be taking the perspective of individual countries? And not eg humanity.
And timescales of perhaps decades?
On longer timescales: people don't get born knowing how to build nuclear bombs. They are trained up.
Depends on how long the interstellar craft is supposed to travel. If it's under 100 years, fission should be able to do the trick of keeping the craft warm and the lights on for the sealed ecosystem to function during the decades of coasting between stars.
Fusion rockets would be more convenient than fission ones because you can store the hydrogen you need in the form of water and water also acts as a great radiation shield while in deep space. Then, to brake, you use your radiation shield as reaction mass for fission or fusion rockets.
If we are talking about much more than that, fusion is probably a better answer as fission fuel will half-life itself into paperweights over a grand transgalactic tour.
I didn't have (only) travel in mind. I was thinking of living between the stars.
So, if you have enough fissiles for keeping the closed ecosystem happy for the duration of the flight, you can go quite far.
The ship/colony will need to enter orbit around a star and drop by a rocky planet at some point, to gather more fissiles and reaction mass (and other materials needed for fixes and upgrades), so it wouldn't be able to stay indefinitely in deep space. If it's fusion-driven, a gas giant may be a good option for both fuel and reaction mass, and icy moons may work well for replacing water.
I'm guessing in a decade we'll have a viable early stage industrial process, and in 2 decades we have commissioned fusion reactors.
If we don't kill the planet with nuclear war or the climate crisis.
The cost per target varies a lot due to the precise manufacturing tolerances and the methods to get them. For example, the sphere with the fuel in it is made by dropping liquid glass from a drop tower. And then metrology is done on hundreds and hundreds of glass spheres.
So though the electricity might cost that, we are talking about a building in which just the lasers and their optical paths take up 3 foot ball fields of advanced warehouse space. And the target chamber is at ultra high vacuum, which is 10 meters in diameter. There are also countless diagnostics, computers, and other electronics, the lights for all the facility, and the number of people required to run it so this delicate experiment goes off without a hitch.
Honestly, it's almost not worth talking about as a power source anytime soon. Even if Q > 2 on NIF there are countless engineering problems that would have to be overcome (and haven't really been thought too hard on in the ICF field) to get a power reactor out of this tech.
My two cents, look towards MIT and CFS for news on their SPARC tokamak and plans for ARC tokamak. Based on some data I have seen, SPARC should hit Q>1 pretty easily. With some estimates of reaching Q> 3 to 9. And before you scoff at it, this reactor design is using magnetic tech that has proven it can withstand and produce a 20T magnetic field! In MCF, field strength and heating are the two key metrics. To put this into perspective, the massive tokamak being built in Europe has a MAX possible field strength of 13T, assuming it's run to the edge of it's theoretical design limitations. The SPARC one hasn't even been run to it's design limitations, most likely due to the mechanical stresses a 20T field produces in a 3-4 meter D coil.
There's a lot of supporting stuff as well as energy to drive that stuff that goes into leading edge tech development like this, that does not matter in terms of the reaction itself.
If they say they achieved more output than input, then I will believe them over a random HN comment snob any day of any week.
> will believe Wouldn't be better if you were able in to verify stuff to some degree yourself instead blindly trusting every expert (not at all implying that the people who did this experiment are untrustworthy but your bound to run into some bad apples with this attitude eventually)
For example p + p Fusion releases neutrinos which then escape any practical device without depositing their energy as heat. This isn’t a concern with DT fusion but again the point is we don’t really care about the actual mass to energy conversion but rather the amount of useful energy obtained.
this is about more power leaving the reaction chamber than what entered it. that's all the announcement is about.
this is NOT about how much energy it takes to ready the lasers. this is NOT about the electricity consumed by lighting, computers, cooling, or measurement or anything else-- none of that counts when you are measuring the efficiency of the reaction itself.
this is about more energy leaving the reaction chamber than went in.
understanding that is key to understanding the significance of the announcement, and this is significant.
and I maintain that the poster I originally called arrogant is arrogant, because they indicated in their comment that they knew how to calculate reaction efficiency better than the physicists doing the work. I called it arrogant because it is --objectively-- an arrogant position to take.
if that makes me arrogant, then so be it. my arrogance is independent of theirs and has no bearing on comments made before my own, and my comment did not influence theirs. (they were being arrogant before I pointed it out.)
Actual power plants are self sustaining as in they use the electricity they produce to operate, it’s mandatory though not sufficient for any commercial fusion power plant.
So, this isn’t about a different way to “calculate reaction efficiency better than the physicists doing the work” he was directly quoting their numbers from the paper. It’s only a question of communicating the meaning of efficiency.
> this is about more energy leaving the reaction chamber than went in.
The exact same energy was there before and after fusion only it’s form changed. It might seem pedantic to point that out, but if you don’t make it clear people will misunderstand.
Also, the applied laser energy also leaves the reaction chamber so any fusion would be net positive thermal energy by that yardstick.
Black start is obviously a different question than being self sustaining.
Ironically, this experiment was designed primarily to simulate the fusion you have in thermonuclear weapons. That's the NIF's purpose and the purpose of this experiment. From Nature https://www.nature.com/articles/d41586-022-04440-7
"Herrmann acknowledges as much, saying that there are many steps on the path to laser fusion energy. “NIF was not designed to be efficient,” he says. “It was designed to be the biggest laser we could possibly build to give us the data we need for the [nuclear] stockpile research programme.”
But pretending to work on "carbon-free energy" is good for funding, just now. Four years ago, being all about weapons opened the tap.
Make no mistake, there is no story here. There will be no "unlimited free energy" from this, or any other fusion project. The fusion startups are spending down investors' money with zero possibility of payback (Helion conceivably excepted), because if they did get Q>1, they have no workable way to harness it. ITER will not even try to produce one watt-second of electricity. Its follow-on demo reactor won't start building until 2050, if not further delayed.
We know the way to get unlimited free energy: solar. Build more, get more. It doesn't have bomb scientists making inflated claims; it just works, and better every year.
They will probably be trying to come up with zero-fallout things they can use tactically.
If anybody succeeds in working out D-3He fusion, that could work in a spacecraft. (D-T, no.) We could probably scare up enough 3He to use for that, if there weren't too many.
Outside the frost line there is a lot of water and a higher percentage of D relative to H so it seems possible to "live off the land" between the stars without being dependent on starshine. A D-D reactor would produce ³He and T, a lot of those products would burn up in the reactor because the reaction rates are high but it would probably be possible to separate some of those out and use it as a breeder reactor that makes fuel for D-³He and D-T reactors elsewhere. I could picture the big D-D reactor running on a large comet or dwarf planet like Pluto producing D-³He for smaller reactors on spacecraft. (D-T not only produces a lot of neutrons but the T has a half life of 12 or so years and won't last for long journies.)
My guess is that interstellar travelers would develop a lifestyle that works around the frost line, where generic bodies above a certain size have liquid water inside. If they were grabby they might consume Ceres or Pluto but might not really care about dry, idiosyncratic worlds like the Earth and Mars.
Having got used to spending interminable ages out in the infinite chill void, they probably have come to prefer being there, so have no desire to roast deep in a stellar gravity well. Their equipment might not even work if warmed too much.
Fine. How do you power a Europa base with Solar? A Neptune probe?
Moon base can be fine with power beamed from a satellite or plain mirrors in orbit, no atmosphere in the way. Might end up being still cheaper than hauling nuclear reactor there plus all the infra to reliably dump waste heat from it.
I guess you're right that solar is useful for 99% of spacecraft -- in that they use it currently. Not a very useful observation
"and many other applications"
Power in polar regions. How well does Solar work in Antarctica? Or Alaska for that matter?
The main difference is that literally anybody can make it, not just "oil exporting countries" and "fuel refiners". And, will. And export excess production when local tankage is full.
Either that or a place near one of the poles where you get water and lots of sunshine. A small fission reactor is a handy thing to have, however.
> Fine. How do you power a Europa base with Solar?
A lot more solar panels, or wire loops harnessing Jupiter's magnetic field and Europa's momentum, etc. Fission is still cool for that.
> A Neptune probe?
Now we enter the nuclear fission territory. Maybe fusion, some day.
For those interested in near term answer:
https://www.nasa.gov/mission_pages/tdm/fission-surface-power...
Do we know how to store it properly yet? How does solar pan out in case of surge ( eg : very cold winter night )
Anyway unlike fusion, seasonal thermal storage is viable and available now, and will be scaled up in immediate future. Also, with electrical vehicles inducing massive investment into the grid, there will be both pressure and resources to solve the rest.
Abundant and cheap are relative terms. Solar and wind could be abundant in a "powers everything we have now and for the foreseeable future of population growth" sense, but maybe not in a "gigantic power-hungry megaprojects which aren't remotely possible today" sense?
What happen when we run out of that ?
The other was deeply ingrained in my understanding. That’s good news. I need to do my own research, like the crackpots are saying.
I do have two question about solar
- is it “drivable” / “pilotable” ?
meaning reacting to surge in the grid? My understanding is that this feature is highly desirable for a grid.
- can we actually build enough solar panel, physically ?
Don’t we need some rare earth thingy that is not in sufficient quantity on our planet as far as we know ? ( follow up : if there is enough, will there be enough in 200 years ? )
Solar panels provide cheap power generation on a schedule. For dispatchability, you rely on storage. There are many different kinds of practical, efficient storage; which are used where will depend on local conditions. Which will be cheapest isn't clear, but probably not batteries. Batteries used won't need lithium, or rare-earths, either
The lie most frequently repeated is that storage needs some sort of "breakthrough". Second is that the small amount built out means more than that there is not enough renewable power yet to charge it from; when there is will be time to build it. In the meantime, we fill in with NG burning. The third is that "pumped hydro", the most common used just now, needs "special geography". Hills are very common.
The lie most frequently repeated about solar is that there is any shortage of places to put it. It is most efficiently floated on water reservoirs, where it cuts evaporation and biofouling, although efficiency is only one consideration. It shares nicely with pasture and even crop land, cutting water demand and heat stress without reducing yield.
There will never be any shortage of wind or solar: need more, build more; materials needed are all abundant. Likewise storage. Costs are still falling as fast as ever, but are already lowest of any energy source ever known.
It's not a lie but is an unfortunate synonym. They are rare in the sense that they are rarified, spread thin everywhere not concentrated in ores.
A new powerfully magnetic iron-nickel allotrope may eliminate much of the market for several of them.
1. Deliberately backing off wind or solar generation from full capacity to provide reserves for demand spikes, transmission/generator outages, etc. This means other generation that may otherwise not have generated at all over that period, is brought online to cover the shortfall.
2. Co-locating grid-scale batteries at intermittent generation sites ("hybrid generation facilities" in energy industry jargon) to cover short-term contingency events.Anyway. What I read is : having something else on the side can make solar dispatchable. Realistically, what would be that other things ?
Nuclear don’t like to be turned on/off. Wind has the same issue… are we saying the good ol’ coal burning kettle ?
With some clever choices in building materials, we may be able to dismantle ITER and its successors to use them as fission fuels.
Even accepting the qualification that's not just a mere matter of engineering, capturing that heat from a source that hot is not without trouble. A bit like how there is plenty of energy in a single lightning strike and yet we can't easily catch it even though in principle 'just build a large enough capacitor and connect it to a lightning rod' is a workable recipe.
> Getting a contained fusion reaction that gives out more energy than input is the problem
Not in the least because the container itself is a very hard problem to solve.
> how to convert that into electricity is not going to be a problem.
It is also a problem, albeit a lesser one.
The better way to look at all of these fusion projects is a way to do an end run around arms control limitations with as a very unlikely by-product the possible future generation of energy. But I would not hold my breath for that. Meanwhile, I'm all for capturing more of the energy output by that other fusion reactor that we all have access to, and learning how to store it over longer periods. Preferably to start with a couple of days with something that doesn't degrade (think very high density super capacitor rather than a battery), but I'll take advanced battery technology if it can be done cheap enough per storage cycle. We're getting there.
https://engineering.mit.edu/engage/ask-an-engineer/is-there-...
Energy from one hohlraum ≈ energy from two lightning strikes
Turning dumb heat into electric power is expensive. Nothing that depends on doing that can ever compete with wind and solar, anymore.
Tritium doesn't grow on trees. Making it by blasting those hot neutrons into a thousand tons of FLiBe is easy enough. Getting your few grams a day, at PPB concentration, out of that thousand tons of stuff is... nobody has any idea how. But you need to, to have fuel for tomorrow.
No, there won't be any of that. It would be fantastically more expensive than fission. Fission is not competitive, and gets less so by the day. Fusion is nothing but a money pit (with the just barely-possible exception of D-3He).
> Turning dumb heat into electric power is expensive. Nothing that depends on doing that can ever compete with wind and solar, anymore.
This isn't even strictly true today when focusing on current "dumb heat sources":
https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#...
"cost of extension of operations of existing nuclear power plants (LTO, long-term operations) has the lowest LCOE of low-carbon energy sources; "
I'm going to go with the OECD and NEA on this one.
> Tritium doesn't grow on trees.
https://en.wikipedia.org/wiki/Breeding_blanket
Saying that there are unknown engineering challenges is kind of a "duh", otherwise we wouldn't be researching we would be implementing. As you also mentioned there are other alternatives which we could consider than tritium.
> Fission is not competitive, and gets less so by the day.
https://www.sciencedirect.com/science/article/abs/pii/S03062... yeah that's not true
> Fusion is nothing but a money pit (with the just barely-possible exception of D-3He).
We genuinely don't know if fusion is a money pit or not, because we don't have any idea how much a successful form will cost. Tritium blankets may be easy or not. Maybe helion's D-3HE will have a breakthrough. Maybe it's ICF.
I've not seen suggestions by anyone that wind and solar build-outs stop, or get diminished. Indeed at this point because the cost are low, industry will continue to invest in them regardless.
However, we will need a lot more energy production than folks think. We need to decarbonize the atmosphere. And that's going to require a lot of power.
All that aside, solar and wind are not getting you to mars in a timely fashion. We have reasons to research fusion that escape large commercial power generation.
Not going to Mars sounds like a great plan. Sign me up!
Simulations with multiple global ecosystem models suggest that CO2 fertilization effects explain 70% of the observed greening trend, followed by nitrogen deposition (9%), climate change (8%) and land cover change (LCC) (4%). CO2 fertilization effects explain most of the greening trends in the tropics, whereas climate change resulted in greening of the high latitudes and the Tibetan Plateau.. https://sites.bu.edu/cliveg/files/2016/04/zhu-greening-earth...
This is not a surprise given that carbon is needed for plant growth, a fact well understood by commercial growers who pipe CO2 into their greenhouses. So one issue might be, if decarbonization is successful then what might be the acceptable level of reduction in global food supply?
Another issue relates to temperature. From an analysis of 974 million deaths in 384 locations across 13 countries it’s been concluded that twenty times more people die from the cold as from the heat.https://composite-indicators.jrc.ec.europa.eu/sites/default/... A recent paper (Dec 12 2022) regarding heart attacks states “extreme temperatures accounted for 2.2 additional deaths per 1,000 on hot days and 9.1 additional deaths per 1,000 on cold days.” Circulation. doi.org/10.1161/CIRCULATIONAHA.122.061832.
Do any of the reports present an ethical problem? No, they do not given an extreme interpretation of climate models.
Direct influence on economic variables and individuals are the smallest of its effects.
You seem to be awfully certain of that. I'm not an expert in this area, but my understanding is that the MIT Arc reactor is planned to use FLiBe as a liquid coolant that absorbs heat/neutrons/etc from the fusion reaction and is pumped into heat exchangers to boil water to run turbines. I mean, maybe there's some details not worked out and maybe I'm misunderstanding how it works, but it seems like a plan to generate electricity to me.
There's no plan to hook ITER up to a thermal plant because it's a research reactor not a power plant, but there's no conceptual reason they couldn't do it. (Not that ITER is a great example; the design is already antiquated before it's even finished.)
Driving steam turbines, even with other costs at zero, leaves you uncompetitive with renewables. But other costs would be very, very far from zero. Extracting the grams of tritium at PPB concentration dissolved in 1000 tons of FLiBe every day so you have fuel for tomorrow is an expensive job all by itself.
Making a whole new reactor every year or two because it destroyed itself with neutron bombardment is another.
Everything gets beaten by renewables when they're at high output.
But renewables plus reliable storage costs a lot more, and there's no way it's cheaper than steam turbines attached to a bottomless source.
The cost of operating a steam turbine far exceeds the cost of the coal or uranium driving it. But the steam turbine would not be the only operating expense for fusion. We don't know exactly what it would cost to sieve a thousand tons of molten FLiBe every day to get out the tritium produced that day, because no one even knows any way to achieve it at all. But it would certainly be a huge daily expense, if achieved.
Who said operating expense only? I was definitely considering capital costs too, amortized over a few decades.
Steam turbines are fine for backing up unreliable renewables.
> But the steam turbine would not be the only operating expense for fusion. [...]
Okay, but I was only addressing the idea of steam turbine costs by themselves.
It should be clear that to build out storage when there is not surplus renewable generating capacity to "charge" it from would be foolish. The immediate exception is to time-shift renewable energy generated at midday peak for evening delivery, as is being done successfully today.
Steam turbines, by contrast, are expensive to operate, and slow to start up and shut down.
Capital expense of renewables is very low already, and still falling. Even substantial overbuild to charge storage from does not change this. Cost of various forms of storage is falling even faster. By the time much storage is needed, it will be very cheap.
So are plain steam turbines, if you have cheap steam.
> Steam turbines, by contrast, are expensive to operate, and slow to start up and shut down.
Huh? Combined cycle setups use steam turbines as part of the system. Steam turbines can ramp up and down plenty fast. It's traditional heat sources that don't ramp well.
> By the time much storage is needed, it will be very cheap.
That would be nice but I'm not depending on it, and I'm definitely not going to assume that long term storage will ever be cheaper than steam turbines.
Interestingly, that's not really true: IIRC the japanese team working on the WCCB breeder module (that uses supercritical water as coolant) plans on connecting the water loop to a small turbine. If they succeed it would be the first ever electrical power produced from fusion.
Making tea would be better theater, if they need that, and cheaper: "the first tea ever brewed by over-unity fusing neutrons".
When (in XX years?) almost all US nukes are only simulated on computers and not actually tested, the Russians may start wondering if the US aresnal actually works, no? That would be a horrible outcome, since it means the Russians would be taking somewhat greater risks in their decision-making. Wouldn't far outweigh any opertaional or financial benefits the newer designs offer?
I suppose one could argue that if the loss of confidence in strategic weapons matched the actual loss in reliability, it might be a "no op" (although even this is arguable). But if the Russians think the US simulations suck, while the US is actually building really good simulations, the loss of confidence would be greater than the actual loss in reliability. In the extreme case, the nukes work great, but everyone thinks they are scrap metal.
Of course, the same happens in reverse: if the Russians are upgrading their weapons to untested designs, the US may start underestimating the risk.
If anything the last year or so has probably made the reverse happening and the US and its adversaries likely both have very high confidence in that the US arsenal actually works.
The fusion for power experiments are using the same laser equipment but different targets and sensors.
If other countries joined, it would be a great outcome.
> If other countries joined, it would be a great outcome.
Why the optimism? Without MAD, it's nearly certain that we'd have a world war at some point in time. Sooner or later, it will surely happen. If you think it won't happen, or won't cost millions of lives, or won't employ re-developed nukes eventually, please tell me why you think so. (No sarcasm.)
* Several concurrent arms races in the Middle East, Asia, and Europe
* A high intensity conflict in Ukraine
* China threatening a land invasion into Taiwan
MAD might be preventing a country like Poland from jumping into the Ukraine conflict, but more likely it’s because of its involvement in NATO.
I think collective security organisations are a far more potent force for peace than nuclear weapons. If countries abided by their security agreements in WW2, then we’d have nipped the entire thing in the bud.
I mean... Only one of those is an actual fight. And there MAD doesn't apply because the defender doesn't have the Assured Destruction capability needed.
Before MAD, for thousands of years, all the big populations were shaped/educated/pushed into limitless sacrifice for the motherland.
> collective security organisations are a far more potent force for peace than nuclear weapons
I think if you take MAD away, the "collective security organisations" would quickly break into good ol' alliances.
Which is to say, possible future proxy wars between the great powers where MAD will supposedly restrict conflict intensity. See below.
> A high intensity conflict in Ukraine
What's going on in Ukraine is a bog standard cold war style proxy war. The NATO plan is basically to turn it into another Afghanistan for the Russians. It's the exact thing that MAD is meant to keep from spilling over into a world war between the principals.
> China threatening a land invasion into Taiwan
This is more interesting. US conventional forces almost certainly have no hope of beating China that close to home. Therefore, any effective US response would require nuking China and China is presumably deterring that with their nukes. There is an argument to be made here that a non-nuclear Chinese military would be in Taiwan's best interests. However, I see no scenario where either a nuclear or non-nuclear China and a non-nuclear USA is in Taiwan's best interests. So while the MAD case isn't the best case for Taiwan here, it's also not the worst.
1. How does this research help address this problem?
2. What are the sources for your opinion?
I see it the other way around, this problem makes me doubt that this research will ever actually lead anywhere, supposing it's even as good a result as it first appears.
> 2. What are the sources for your opinion?
It's a fact. And my source is dead tree media. I don't recall all the details, but there are some very finicky parts that go into a state of the art warhead and we have lost the capability to manufacture them. Is this really so surprising? We can't even build new F-22s anymore!
This research successfully initiated fusion, using a capsule of hydrogen made of some material, surrounded by something, with an outer layer. This outer layer is turned into X-Rays by the laser, which then ablate the hydrogen capsule's casing casing the inwards pressure. You could speculate, that they just found the makeup for something that would replace the Styrofoam, or we just improved upon it.
Similar to the "we can't make concrete as good as the romans" line of woo. Caveat Emptor
[1] https://www.motherjones.com/politics/2009/05/fogbank-america...
And that absolutely was not a non-sequitur.
Also, there is a constant need to improve fusion/fission rate in the total energy output, and perhaps eventually design pure fusion weapons, though this is still probably out of reach.
When castle bravo was tested, we didn't knew that lithium7 fusion was possible and that it would generate energy. The bomb had a lot of lithium7 because it was cheaper than lithium6. Castle Bravo then proceeded to explode with way more power than intended, it vaporized the measurement instruments, ruined the test site, damaged civilian property and caused a horrible amount of fallout that screwed a enormous amount of people from more than one country.
Even during war, I suppose you want your explosions to behave in the way you expect... so you need to figure out all the physics related to them.
The sun actually has very little fusion per cubic metre or per kg.
Per volume the core of the sun produces only a quarter of the heat of the human body (and per kg it's even less, owing to high density).
That's why our fusion reactors can't just mimic stars, they have to far surpass them to be useful to us.
Good old Wikipedia has this gem:
> The large power output of the Sun is mainly due to the huge size and density of its core (compared to Earth and objects on Earth), with only a fairly small amount of power being generated per cubic metre. Theoretical models of the Sun's interior indicate a maximum power density, or energy production, of approximately 276.5 watts per cubic metre at the center of the core,[63] which is about the same power density inside a compost pile.
https://en.wikipedia.org/wiki/Sun#Core
Another fun fact: there's a decades old design for a gadget that fits at the top of your desk and does nuclear fusion. You could build one yourself, if you are sufficiently dedicated. Unfortunately, no one has ever worked out how to run one of them as a power plant. Ie how to get more useful energy out than you have to put in.
But here is a MAKE magazine article explaining how to build! https://makezine.com/projects/nuclear-fusor/
> The highest instantaneous pressures we can obtain here on Earth are in the Fusion reactor at the National Ignition Facility and in Thermonuclear weapon detonations. These achieve pressures of 5 x 10^12 and 6.5 x 10^15 Pascal respectively. For comparison, the pressure inside our Sun’s core is 2.5 x 10^16 Pascal.
So for black bodies with identical shape and linear dimensions R1 and R2, with identical power production per unit volume, both in thermal equilibrium with whatever is outside them, you would expect:
R1/R2 = (T1/T2)^4
(because setting power produced equal to power radiated gives R proportional to T^4).
Pretending humans are spheres with radius 1m and the sun is a sphere with radius 7*10^8m, you would expect the sun to have ~160 times the temperature of a human at equilibrium in vacuum. It's going to be lower because not all of the sun is power-producing, of course. But higher because a human is not 1m in radius. And again higher because humans are not spheres and lose heat more than a sphere would for the same volume (more surface area).
The sun is about 6000K on the surface. That would give us ~40K for the equilibrium temperature of a human in vacuum, which at least seems truthy.
TL;DR: the sun is big, with a small surface area compared to its volume, because it's big.
One square inch of sun has billions of inches of hydrogen behind it making heat.
If it produced a quarter of the heat of the human body per volume, its temperature would be lower as well (less than 37 degrees Celsius).[1] This is obviously not the case.
[1] Obviously heat and temperature are not the same, I know that. But when something’s temperature is higher than another thing’s, then heat is exchanged along that gradient. Meaning if the sun produced less volumetric heat than the human body, a human body placed within the sun would warm the sun and cool the human.
For both the sun and a human on earth there are two processes going on:
1. Heat production per unit volume.
2. Heat loss per unit surface area.
The volume to surface area ratio for the sun is much larger than for the human, for a minor reason (the sun is a sphere) and a major reason (the sun's linear size is much bigger). So the equilibrium temperature of the sun in the same ambient outside environment is higher than the human's.
Your thought experiment about placing a human inside the sun would in fact work as you say, if a human body continued to produce heat once it had achieved thermal equilibrium with the surrounding plasma.
I guess you can call that a crisis.
(Also - thanks for sharing one of the most interesting comments I've read on the internet in quite a while.)
I fully expect a working fusion plant of some kind by 2030, assuming funding increases. Once we get them commercialized; coal, wind, solar and other power production will be obsolete for the most part. We can also use fusion heat to separate waste into it's base elements (you can recycle anything!), and help make any process needing a lot of thermal or electrical energy more efficient.
Right. The first law of fusion physics: working fusion power generation in 10 years. It has been proven true for the last 7 decades. Rock solid.
People paying attention over this time have noticed it getting closer as we improve our capabilities.
The next iteration of the joke will be 'fusion was always inevitable'
https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy
Give it a read. Intertial confinement fusion with a Q > 1 may very well point the way towards a realistic powerplant. Fusion is at a point it deserves investment. The NIF cost about the same as a single b-2 bomber.
[1]http://large.stanford.edu/courses/2021/ph241/margraf1/images...
That would be fine, except some of the investors are pension funds.
IANAP, but I see no path forward to sufficient Q-total using plasma fusion to put this to any practical use. Unless the reaction can somehow be self-sustaining, I do not believe this will ever work.
> LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE). Many advanced science and technology developments are still needed to achieve simple, affordable IFE to power homes and businesses, and DOE is currently restarting a broad-based, coordinated IFE program in the United States. Combined with private-sector investment, there is a lot of momentum to drive rapid progress toward fusion commercialization.
It's fusion Manhattan project time.
they're working on getting you to click on an ad
I'm a pretty smart dude. I'm no big deal on HackerNews or in Silicon Valley, but I look easily 10x as smart as most of the normal people I come across in the real world. And I regularly come across people so much smarter than me, they have to explain things to me the same way I talk to a toddler
I'll bet a lot of geniuses are congregating in cool orgs like those where they can make a real difference in the world.
This generation was classically educated, without TV or social media in their childhood. They spent the time we're wasting on HN reading _books_ and following the discipline their elders learned in WWI. They had plenty of occasions to tinker.
I claim the brains of those generation was structurally different from ours, and we're talking about the best minds of this generation.
It's a trope to say that our "best minds are working on ads" - the reality is that, no, we webshits are not the "best minds".
"The last generation was better because they read _books_ and had _discipline_ and didn't waste their time on frivolous garbage" is also a trope.
People having been saying "this next generation is inferior to the last one" since the ancient Greeks. If that was consistently true we would already be in an Idiocracy scenario.
Been on Twitter, Facebook, or Hacker News lately ?
More seriously, I really fear this kind of stuff is, to some extend, new : https://sitn.hms.harvard.edu/flash/2018/dopamine-smartphones...
(Although, maybe it's comparable to the "opium epidemics" of the 1800s ?)
Ironically, I should stop having this kind of conversation... On social network.
World changing people seem to me to be very much the right people in the right place at the right time. The best way to find them is to try to create those places now.
Opportunities for WWII and post-war era research don’t exist now. Everything with funding is very short term, politicized, and narrowly focused within a micro specialty.
Realistically, I don’t think that will change until it has to.
They're not, and there's zero evidence to back that frequently floated premise up. That's a particularly laughable myth created by those same industry people to feel better about their terrible life choices. If you can't do something meaningful, at least you can pretend to be a genius doing nothing meaningful. It turns out that both things are false, they're not brilliant and they're wasting their lives.
No, the brilliant people are working at TSMC, Intel, AMD, nVidia, Applied Materials, ASML, Illumina, ARM, TI, et al.
They're working on CRISPR. They're working on mRNA vaccines. They're working on stem cells. They're trying to cure HIV just as the same type of people cured hepatitis C. They're working for Moderna, Pfizer, BioNTech, Roche, Novartis, Amgen, Regeneron, Sanofi, Gilead, Merck, Glaxo, et al. They're trying to figure out how to roll back or cure Alzheimer's. They're dedicating a lifetime of work into exploring the human genome, so that future generations have a much better, much more useful map.
They're working on robotics at Intuitive Surgical or Boston Dynamics. They're working on self-driving tech. They've been building out the massive, global cloud infrastructure. They're at NASA, or SpaceX, or ESA and they're doing the work to get us a base on the moon or to Mars. They just got done building rockets that can land upright. They're building a massive, extraordinary, global satellite system in Starlink.
They're working on fusion.
And so on and so forth.
Ad clicks? Yeah right. They're not even in the room.
[1] This is up 1.1% year-over-year, and only up 6.5% p.a. over the last three years - not a pandemic-driven bubble. Source is https://www.redfin.com/county/733/IL/DuPage-County/housing-m...
Maybe he was like you describe long ago but something...happened.
I'm not very excited in hearing we'll get even more powerful thermo-nuclear bombs.
And yet that's exactly why the NIF was actually built. They do plenty of weapons research: https://wci.llnl.gov/facilities/nif I'm told the building was even built to switch over between civilian and classified use unusually quickly, but I'm having trouble turning up a citation for that right now with just my phone and 2022-Google.
> All of the difficult problems fusion power generation faces with long-term plasma confinement go away when you're just trying to squeeze as hard as you can and are willing to use fission bombs to do it in an otherwise uncontrolled manner.
Not if you want them to fit in a submarine warhead. This sort of work is not easy to do well.
You're both half-right.
The NIF is the replacement for nuclear tests. It's necessary to maintain the arsenal in a working fashion, as the warheads degrade over time and have to be replaced with new ones. https://www.npr.org/templates/story/story.php?storyId=655921...
The NIF is not for more powerful nuclear weapons, as that's entirely unnecessary. If anything, most interest these days is in less powerful weapons for potential battlefield use.
It's not the only thing they do.
“It’s a big milestone, but NIF is not a fusion-energy device,” says Dave Hammer, a nuclear engineer at Cornell University in Ithaca, New York.
Herrmann acknowledges as much, saying that there are many steps on the path to laser fusion energy. “NIF was not designed to be efficient,” he says. “It was designed to be the biggest laser we could possibly build to give us the data we need for the [nuclear] stockpile research programme.”
You're right that increasing the yield was a bad example from my side, but the purpose is to improve the weapons, nothing else.
> What do you think the US nuclear weapons research lab will use their research for?
Why do you think that fusion is not enough? Complete strategic energy independence for the US, and dominance in the electricity sector? That's so, SO much more valuable than better nuclear weapons.
That's why MIRV was introduced. One ICBM delivering 10 - 20 small warheads result in much greater devastation than an equally heavy warhead in one package, because less power is wasted on air and space.
It's morbid math, but it makes sense.
Although, it would be interesting to see fusion reactors on planes and ships powering other types of weapons like lasers and more powerful railguns or faster icbms.
A relatively recent example: development of cancer chemotherapy began with the incidental finding that the chemical warfare agent nitrogen mustard reduced the white cell count of affected soldiers.
We make progress building on the shoulders of giants, but those giants are often standing in dung.
It will be time to unleash resources once they have a working fusion reactor design in order to build fusion power plants and the industrial infrastructure required to supply them.
Until then they should of course get the resources they need but I don't think throwing money at them will necessarily speed things up.
Plutonium was significantly more easy to produce, but it did require some novel engineering for the implosion lens. They weren't sure it was going to work and did, in fact, test the bomb before dropping it on Nagasaki.
I think the Manhattan project is a great example of where more funds can help; if the funds were more restricted, it's entirely possible they would have gone with the "sure thing" of the uranium bomb instead of spending resources on the less sure plutonium bomb. Trying out multiple ideas in parallel often "wastes" money since if you try ideas in tandem, you will always try the high-percentage ideas first.
Maybe he doesn't actually believe in Starship.
Musk has very obviously poor impulse control. Someone more contained, patient, less impulsive, would have waited and taken a more strategic approach to acquiring Twitter (which would have left an opening to let the stock implode with the rest of the tech market, after which one could have pounced and grabbed it for far cheaper). On the flip side, that less impulsive person probably wouldn't have started SpaceX in the first place (given the suicidal fiscal task involved and context at the time in the industry), or wouldn't have gone to the financial extremes required to make it succeed (betting essentially all of his wealth on Tesla and SpaceX).
I know it is popular/easy to hate on the man right now, but this is a really strange take.
Given that Musk has been talking about mars since at least 2001, many years before he had the resources he has now, and almost went bankrupt funding spacex's first orbital rocket, it's hard to believe he's pretending.
People seem happy to believe all negative things they hear about him, but discount anything that doesn't gel with this negative image. It's like how the same people who put all missteps of Tesla/SpaceX at Elons feet, will also discount any of the successes and say he has nothing to do with them.
Things like Hyperloop also make more sense in that context.
And this could still be true.
People here act like he bought Twitter and then deleted the website. This isn't the case.
Did he overpay, yes, but its still a business that is worth something.
I was told that Twitter would collapse and die any day now a month ago.
It seems to be holding up well enough during the current mega world event known as the FIFA World Cup.
But yes, it was clearly a mistake.
You mean wars for oil? Fusion would not solve that, that wars were not about energy per se but about control and domination, keeping USD as world reserve currency and US as world hegemon. Look at Taiwan and chips situation, no oil there, there will be always some "oil" out there that you will want to control instead of giving that control to your rivals. It's game theory 101.
people love to invoke game theory but fail to explain why only we spend more than next 10 countries military budget combined. plus its quite unclear what we get out of it because of all the secrecy & likely its mostly inflated costs and kickbacks. The wars in Iraq/Afghanistan themselves have cost close to 3T over time & thats outside of annual budgets. Personally I'd have preferred to take medicare for all for that amount of money.
Unfortunately no, you can't go more calm because projection of force is what keeps status quo and your rivals in place, not liberal values or clearheaded minds. There is no world police, the one with the biggest stick makes the rules. US is not the first hegemon in history of the world, we had Roman Empire, we had Dutch Empire etc, all of the world hegemons were major military powers. There is always some challenger waiting in the shadows to take over your position, you can't just sit and be calm because you will lose what you have, I assure you that others will not just sit calm but claim what's yours if they see sign of weakness, history proves that again and again.
> but fail to explain why only we spend more than next 10 countries military budget combined
Well it's easy to explain, US have it in its doctrine that it needs to have military strong enough to fight 2 wars at a time so it needs to spend more than at least a few countries behind it but a lot of this budget is probably not spent well. The problem here is that when you stop being world hegemon with the biggest stick, your currency stops being world reserve currency which means you can't finance your debt the same way as before, which has drastic consequences to your budget and it would be really fatal for US. Sometimes you just can't stop the music even when you don't like the melody because silence will hurt you.
> plus its quite unclear what we get out of it because of all the secrecy & likely its mostly inflated costs and kickbacks.
Agreed that's inefficient, you probably could achieve the same with lower costs but how much lower I don't know if anyone knows.
Edit: I'm Canadian, the question is rhetorical.
https://www.nytimes.com/2021/08/10/technology/commonwealth-f...
$1T to move fusion forward just 5 years from eg 2040 to 2035 could alone have a huge ROI in terms of climate mitigation and decarbonization
Further, it's possible that fusion plants might be prohibitively expensive to build and maintain, even if their fuel is cheap.
In fact carbon removal might be a great way to subsidize fusion at the outset so that it can be overprovisioned/have a guaranteed minimum price
Energy estimated is 1,200 kilowatt-hours per ton of CO2 removed.
Nuclear fission energy averages 0.4 cents/kWh. That's $480 in energy costs alone (ignoring profit margins for removal, etc).
Why would bleeding edge fusion that requires cutting edge lasers, magnets, and various other containment stuff have a cheaper energy generation cost? I could be wrong, but I don't think nuclear waste (which is the primary difference with fusion) is the primary cost contributor. So why would you want to invest in more expensive fusion to remove all this carbon instead of cheaper fission? Nuclear waste by the way isn't waste. It can be reused in breeder reactors and it's used a lot in medicine (I could be wrong but one of the reasons nuclear imaging has gotten more expensive is because radioactive materials are more difficult to obtain due to reduction in global fission energy).
I suspect the regulatory environment is from regulatory capture by the fossil fuel industry. Otherwise why would Gen IV reactors, which can’t meltdown, be suffering many regulatory delays? What kind of nuclear proliferation concerns exist for reactors built and deployed within the US?
After decades of R&D fusion should become significantly cheaper than fission per kWh if only due to having less of a regulatory burden and smoother permitting process.
It’s more expensive now, but in the long run it will be cheaper.
For example, nitrogen fixation for fertilizer currently uses natural gas almost entirely for the source of hydrogen. Vastly cheaper energy means it would make much more sense to switch this to electricity, https://www.frontiersin.org/articles/10.3389/fenrg.2021.5808....
But I agree with your sentiment, there are a lot of engineering details to consider before one can shout "free energy".
>Russia accounted for about 55% of Germany’s natural gas imports and 35% of Germany’s oil imports last year, causing Germany to resist a blanket European Union ban on Russian energy.
If every country could assure their energy independence, geopolitics would look very different. Yes, there are still many problems, like natural resources. But if you can assure all your residents can keep the lights on, their houses warm and the economy moving (EV's for transit, technology)... its very reassuring.
Also, there should hopefully be much less pomp and process around fusion compared to fission due to the safety/radiation profile being much safer.
What? Cost is THE problem with nuclear energy.
You must have some bizarre way of framing things to make today statement - you should at least tell us what that is since you must know that you are making a controversial claim.
No amount of investment into solar power can make the sun magically shine 24 hours a day.
Solar + reverse hydropower, solar + synthetic fuel manufacture, solar + appropriate sized batteries, solar cranes-with-weights, etc.
Solar is so cheap that all those are plausible. Fusion is still far from ready.
Solar panels are cheap and the market appears to be fine with unreliable power[0] if it's cheap enough.
[0] Unreliable, but predictable that is. You can estimate with decent confidence what the weather will be like tomorrow and you can definitely tell what it's going to be a few hours from now, so energy auctions a day ahead are feasible.
HVDC lines help with this a lot. It has gotten to a point where there are serious plans to build a long, undersea HVDC line from the UK to Morocco which, get this, is poised to cost less than the equivalent(GWh delivered annually) Hinkley Point C nuclear power plant:
https://xlinks.co/morocco-uk-power-project/
That's how cheap the combination of solar and HVDC is.
We should be installing more solar & wind, but that alone is not a solution to our problems.
Total US energy generation 2021: 4 trillion kwh
Average power generation: 457Gw
Cost of Topaz solar farm: $2.5bn Potential output: 550 Mw Cost per Mw $4.5m
Spend a trillion on similar capacity, you get 220Gw potential output.
But that's assuming you get 550Mw average. In fact, it produces about 1282Gwh output a year, so average is more like 145Mw.
So at a rough estimate, you need more like 10 trillion to meet US electricity demand. And that assumes you have unlimited battery storage for free.
And of course electricity is a small minority of total energy use.
Incidentally, I think it's amazing you get to about 10% of total electricity needs with only $1tr, i.e. around 4% of US national output.
https://en.wikipedia.org/wiki/Topaz_Solar_Farm https://www.eia.gov/energyexplained/electricity/electricity-...
```python trillion_dollars = 1e12
mw = 550
cost_farm = 2.5e9
cost_dollar_per_mw = cost_farm/mw
num_mw = trillion_dollars/cost_dollar_per_mw
num_gw = num_mw/1000
num_gw
kwh = 4e12
mw = kw/1000
gw = mw/1000
gw ```
That's quite high. Here in Germany they assume 530-800€ per kW_peak for a utility-scale ground-mounted system (2021) [0]. You can add additional CAPEX for inflation and expansion of the grid, but <$1500 per kW_peak (aka $1.5m per MW) should be quite possible. Especially if you include scaling effects.
If you add batteries for night-time balancing, LCOE roughly doubles for now.
Economically, no other energy source will beat non-winter day-time PV in the foreseeable future. Imo, as long as other plants are running during those times, investing in PV is a no-brainer.
[0] https://www.ise.fraunhofer.de/en/publications/studies/cost-o...
We aren't "heating up the planet" .. we're "insulating the atmosphere".
Increased C02 (and the close following methane and water vapor increases) serve to trap more of the heat radiated outwards that would otherwise escape.
The vast bulk of that heat comes from the visible light of the sun which passes easily through the atmosphere coming in, gets converted to IR energy as it warms the earth and oceans, and then escapes outwards.
Our changes to the atmosphere have disturbed that balance.
Your comment has some small merit, but you would need to work through the heat output of human generated power and then compare that to the daily heat energy originally from the sun that radiates outward.
We are doing both. We are doing more insulating than heating, but we obviously generate more heat.
If so, how'd you do on the numbers?
Is it x10, x100, x1000, .. more?
This is after all the part that matters.
The original question is a good one. We will use more energy as it gets cheaper (see monster trucks, Las Vegas, Dubai). We should be thinking of what we will do with the waste heat when everyone has a fusion reactor.
To be clear I made a qualified assertion; the phrase "Relative scales of various factors matter here" does the work.
> Obviously we get more heat from the sun than we generate on our own.
Yes - but, again, How much more?
If it's barely twice as much (which seems unlikely) then heat from our activity is a major factor in all this.
If it's 100,000x times more then I stand firm, heat from our activity has effectively zero impact on the AGW issue (although other by-products from our daily routines are the crux of the problem).
If it's some other factor then what relative signifigance does our human heat generation have?
> I have no idea.
It's a shame you didn't grab an envelope and make use of the back, it's a classic Fermi problem [1] of the kind I and my class mates were posed in high school and the kind of thing many other HN commeters would delight in taking a run at.
If you're feeling game you might like to start with the daily heating of the earths surface from the sun, and then look at the petajoules of energy generated and consumed per day and take a stab at guesstimating the waste (unused, released into the lower earths surface layer) heat as a percentage (or google efficiencies, etc).
Have fun!
EDIT: from quick google query it looks like per day earth receives equivalent of yearly power consumption (not only electricity but also fuel). So we would need to x356 our energy consumption which is not that much unreasonable if you could have for example heated outdoor pool for free anywhere in the world.
nothing will stop climate change. The earth’s climate will continue to change regardless of any human interventions
Lasers are pretty inefficient. How much energy did it take to make 2.05 MJ of lased light?
Does this breakthrough have a reasonable path to to make more electrical energy than it puts in?
[1] https://www.theregister.com/2015/01/29/charles_townes_nobel_...
Not having to chase your next meal can make a big difference
I wish billionaires would fund things like this directly as in no patent no nothing, just from the goodness of their hearts, which they claim is there seeing how much they all pledge to charities... But the reality is different, Oxford pledged to donate the rights to their covid vaccine for free then was urged by the bill & melinda "foundation" to reverse course and sold it to pharma companies.
Happy Ignition Day everyone. I can hardly believe we really made it here.
Allegedly ignition was achieved a year ago. How is this different?
> In August 2021, NIF scientists announced that they had used their high-powered laser device to achieve a record reaction that crossed a critical threshold on the path to ignition, but efforts to replicate that experiment, or shot, in the following months fell short.
Fluke or measurement error, it seems.
It’s not a fluke anymore and I assume the engineering behind this is now understood well enough to develop it further and scale it up.
Fusion for the most part isn’t a physics problem it’s an engineering problem the difficulty was always in how to implement it in the real world rather than in math at ideal white paper conditions.
If these are the same thing, why didn't they make a big deal about it before? What's the material difference?
But it is weapons work, first, last, and always.
So the important point here is, there was no net energy gain. They spent 300 megajoules to get 2.5 out. The scientists only talk about the 1.8 megajoules of laser energy sent to the target, not about the 300 megajoules of electricity needed to send 1.8 megajoules to the target.
See how pedantic and not helpful that is?
There are some nuances regarding the distinction between rest mass vs relativistic mass, but they're not really relevant in this context.
I think what trips people up here is confusing mass with matter. Matter is also subject to mass-energy equivalence, of course, but AFAIU in most common types of nuclear reactions little if any matter, per se, is transformed.
You can't run your laser on mass or air, if you need a coal firing power plant to run your fusion reactor, from which you get less than you consumed from the coal plant...
It's great progress, it's just not as close to viable as it might sound like - more breakthroughs needed.
Seems like an overcorrection to something I haven't even seen anyone here say.
I'm not saying they've claimed anything wrong or deliberately misleading, it's just a misunderstanding/misalignment and possibly made worse by the PR teams in the middle.
In other words, I don't think it's an angry 'well actually' type correction so much as it is disappointment - it initially sounded even greater.
Tangentially, it does seem fairly intuitive that it should be non-linear in that 'jump start' as it were: a fire can be grown arbitrarily large having started from a single match (or flint or whatever).
"In terms of the physics, we are basically there, and the rest of it, at some level, is just engineering," he said.
[1] https://www.cbs58.com/news/wisconsin-reacts-to-breakthrough-...
This is scientific breakthrough. The best point of comparison is probably a fusion bomb, which requires an initial fission detonation to create enough pressure and free neutrons to force a net-positive fusion reaction. But at the NIF they do it using only lasers… incredible.
(Sent from my ENIAC)
My kids are likely to spend the majority of their lives living a world where energy is clean, cheap, and available to everyone. Climate change is something that is not only going to be stopped, but can be reversed for them. Energy grids can be made to be smaller and mutually supporting, lessening the impacts of disasters. Oil dependency and all the political problems that come with it are going to be gone by the time they are grandparents. Nations like Nigeria and East Timor can have power generation like everyone else. The deserts and oceans and tundra of their lives will be places dotted with little greenhouses and fresh vegetables. If they get this down to the size of a car, then everything opens up for travel and recreation. The only real baseline I have to use here is Star Trek.
Of course, there is a long way to go. There is a lot of work and show-stoppers still out there. And the ideas that I see as their future are just sooooo tiny compared to their reality. I'm thinking of faster horses and they're going to live in a world of supersonic jets. That kind of difference and small thinking of mine.
I'm so happy that, assuming the best with fusion, they are going to live such better lives.
At the very least we can likely pull carbon out of the air faster than we put it in. No more destructive hydropower, no need for fission plants, radically reduced costs for industrial manufacturing. Cheap energy could make raw resource extraction much cheaper and more easily automated. Fast transportation, vertical farming. With the concurrent innovations in battery tech, robotics/automation, and electric vehicles and ships, the future is looking incredibly bright
> no need for fission plants
Not sure why this is a goal in and of itself. Everything you said is available today with fission and yet still too expensive to remove CO2. Fission has a more real shot at getting to the right price point before fusion even gets off the ground so why not push for more arrows behind something that's likely to help in our lifetime?
If energy cost very little, we could do previously unviable things like vertically farm and let farmland go back to nature, smelt ore onsite, or run simulations/models for a fraction of what they cost now.
I’m trying to show you that fusion isn’t going to magically rain energy mana down on us. It’s just fission with less waste (if you discount newer fission designs) except and potentially safer (if you discount newer fission designs) It’s likely significantly more expensive given it’s a more complicated reactor and we’ve built 0 commercially (and even with this achievement we’re not that much closer).
My point is, if you’re looking for boundless carbon-free energy, fission reactors already meet all the needs. Additional investments would get reactors that would generate waste competitive with fusion (and in fact can consume all existing generated waste as fuel) and are similarly safe (no runaway reactions).
I would encourage you, if you’re serious about carbon-free boundless energy, to devote your advocacy to advancing fission reactors. They’re here and there’s a straightforward R&D path to get the new reactors (regulatory hurdles are another thing). Fusion reactors won’t be here in any reasonable time frame (even if we had a workable design today it would take many decades to build them and then upgrade the grid).
Unless you're in your early teens and don't plan on having kids until you're in your 30's this proba
The consequences of that cheap energy (fossil fuels) is yet to come, that's the climate change problem. And it is big.
Now let's pretend we get fusion to work: maybe (just maybe) that could help the climate change issue (unless it takes decades, in which case its too late), but that won't change the other big problem we have: with cheap energy, we destroy the planet to build malls and swipe TikTok.
We need to re-learn to live with less energy, that's the only way.
I love the optimism but it sets you up for failure and disappointment when you start thinking about all the free energy your children will have from this.
Free energy from a very successful fusion experiment called the sun bathes our planet every day. We know fusion works, but the devil is in the details.
One of the most fantastical aspects of Star Trek was the societal evolution into one without interpersonal conflict, the idea being that without scarcity there's no good reason for conflict... I'm just not sure how well that would hold up, knowing people. I don't think all desire for status and power stems from scarcity of resources, and people will continue to lie and do harm to each other as long as they desire power over others.
> My kids are likely to spend the majority of their lives living a world where energy is clean, cheap, and available to everyone.
Being available to everyone does depend on who "everyone" is. If people use the energy to grow food (and more people) until we run into some other population-limiter, we'll always have too many people. Part of achieving sustainability is ending runaway growth. Maybe you can ask people nicely enough to stop reproducing, maybe education will do it, maybe nothing short of force will. Yet our economics were built around continual growth. So, that's all a big problem to solve, still.
Anyway, based on ITER [1] to equate the energy production of a 1000MW coal plant you would need 2.7t of coal for that plant or 250kg of deuterium and tritium for the fusion reactor (split equally). Based on [2] deuetrium costs about ~$15k a kg. But tritium is ridiculously expensive, at $30k per gram (!) [3].
This leads to a calculation of ~$700M for the coal plant and ~$3.75B for the fusion plant (of which only ~$1.5M is deuterium)
I have a few questions and I wonder if any can help:
1. Is the above fusion fuel correct?
2. What measures are expected to bring these prices down to price efficiency?
Of course, I am not calculating the cost it would take for the reactor, storage, delivery etc.
Nevertheless, this is an absolutely incredible development and the people working for this progress should be definitely proud of their work. My generation and the ones following will hail this as a breakthrough moment. Thanks!
[1]: https://www.iter.org/sci/FusionFuels
[2]: https://en.wikipedia.org/wiki/Prices_of_chemical_elements
[3]: https://www.science.org/content/article/fusion-power-may-run...
D-T fusion almost always breeds tritium in the blanket.
How would it affect the rough calculations above?
Tritium decays in a decade. To start, you'd need the expensive stuff harvested from the heavy water of spent fuel pools. After that, you'd let your neutrons breed it in lithium (or boron, if you're fancy).
There also is no enormous market for tritium. So in short, fusion reactors exist on both sides of the tritium market, by becoming the primary producers and consumers of it, which should lead to significant drop in price of tritium.
How much do these things ring true in this case and what are ideas of improvement?
Parent post suggests that tritium is a fixed cost, more like a construction cost than a fuel cost. We can’t answer this question without a lot more information. We’d need to know how much tritium is needed to reach the point the reactor breeds more than it consumes, if at all.
While the gain NIF achieved was about 1.5, there is good reason to expect it can be scaled up. Ignition is a runaway process, so small changes in the input can result in large changes in the output. Hydrogen bombs, which also use a burning plasma as was demonstrated here, also suggest that the gain and yield may be scaled up.
[0]https://royalsocietypublishing.org/doi/10.1098/rsta.2020.005...
[1]: https://en.wikipedia.org/wiki/Cost_of_electricity_by_source
Imagine the cost savings in miniaturizing electrical grids.
For me, the question here is: can we get our energy to cost 90% less than it did?
Don't get me wrong, I recognise that this is still a huge win (especially environmentally) and that it can have huge runway effects (eg. much more effective decentralization etc.) but it's quite interesting on how we can get these billions of people out of poverty first (or during).
https://www.moltexflex.com/flex-reactor/
A small fission reactor can do almost everything a fusion reactor can. Fusion fuel is higher density, but fission density is already not an issue.
Fusion still needs to heat water, that's where much of the cost comes from.
A fusion reactor does not pose environmental risk and could eventually run on highly available basic elements for everything after the initial "startup" once the technology progresses.
An fusion reactors don't actually run on basic elements. The require a fuel that is specially breed. And when they operate they have radioactive materials that can go airborn.
Hydrogen bombs are driven by indirect implosion by a nuclear primary. It isn't a runaway process; the yield of a secondary is limited by the implosion achieved by the primary. Most hypothetical designs for an inertial fusion power plant achieve similar energy gains.
I think the biggest reason nuclear energy stopped being built is it takes too long to get political wins.
NuScale and other SMNRs might be able to help with that.
However, the capital costs & construction time for Fusion Energy should theoretically be much lower than nuclear reactors.
But are we too far away from it being a reality that anyone is predicting how much?
And one still has to deal with many of the same radiation challenges fission plants must deal with. A large quantity or radioactive tritium must be kept on site and neutrons from the fusion reaction will make the reactor radioactive. In fact, fusion produces more neutrons than fission per unit energy. Even so called 'aneutronic' fusion would have side reactions which would produce quite a lot of neutrons.
Fusion is a lot more complicated than using special rocks to boil water.
The main advantage of fusion is a political one. It politically nigh impossible to build a fission reactor in a suburban industrial park, but Commonwealth Fusion Systems is doing exactly that with a fusion reactor[0]. And there is also the slim possibility this type of reactor could explode. Said reactor uses superconducting magnets which store a lot of energy and if something goes wrong, it would be possible for them to release that energy fast.
But, the NRC hasn't made laws for regulating fusion power yet, so they are able to do this.
[0]https://cfs.energy/news-and-media/commonwealth-fusion-system...
Maybe then current Gen3+ reactors.
But there is no way they will win economically against GenIV Fission reactors. That are already solving most of the issues with Gen3+ reactors.
They already are much smaller, and therefore much lower CapX. Fuel cost are even cheaper because of better utilization of the fuel. Modern plants operating cost are also less because they are even more automated and need to be refueled less.
There is no practical way fusion can compete in my opinion.
Nothing that happens at the NIF is very useful in heading towards commercially viable fusion. The design of the testing apparatus is also similarly incompatible with making a sustained fusion device as there is no way to continuously feed in fuel into the device, nor methods of extracting the energy.
Research wise, it's a pretty big chunk of money. But yeah, more money in research would be nice. (Disclaimer: I am a scientist with grants.)
> the ITER Members China, the European Union, India, Japan, Korea, Russia and the United States
"Ignition" means the reaction becomes self-sustaining and does not require any further input of energy to continue.
The fact that this indeed was ignition was one of the main reasons why the fusion reaction itself was net positive.
I don't see this anywhere in the article. Is there a better reference for what actually happened during the experiment?
The first time they achieved ignition was in August of 2021. See paper below:
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.12...
This is applicable only to continuously running reactions like in jet engines.
Fusion won’t cause a runaway reaction — in fact it’s brutally difficult to get it to react at all, hence why this is an achievement.
It also doesn’t use materials that can be used for a bomb, again unlike fission.
As a result it has the potential to be cheaper to implement, cheaper to fuel, with no meltdown risk.
To illustrate how little it's controlled-- I have a little bit on my keychain as an alpha source with a phosphor so my keyring always glows.
And whilst I won’t doubt that if fusion ever becomes commercially viable the reactors would be walk away safe it doesn’t mean that you don’t need to account for that in your design.
But yeah, future energy will be a mix of available technologies, not a single technology alone. So you need e.g. fusion (or fission) for "baseline" power and wind/solar for peaks
The cleanest energy available now is nuclear fission, but there is no money in it for the energy industry. It is too plentiful and cheap if implemented properly and capitalism does not like plentiful and cheap.
France has had cheap electricity for decades and it seems it has been so cheap that they don't want it anymore.
This is all capitalist boondoggles.
I think you've understood it.
Imo fusion is never going to be able to compete with renewables+storage with the energy being captured from neutrons. Maybe reactions that release energy in charged particles or photons could, but they're even harder to do.
Also, when comparing to renewable+storage you have to consider how much land has to be dedicated to energy use in these scenarios. Wind and solar require orders of magnitude more than a potential fusion reactor (or an existing fission reactor).
The easiest fusion reactions to make happen release most energy as neutrons. But neutrons are, from a practical standpoint, a huge pain in the ass to deal with. They just fly off until they hit another atomic nucleus.
They irradiate the structure of reactor, making it radioactive and weakening it, neccesating periodic replacement. This means handling radioactive materials, which as the existing nuclear power industry demonstrates, is hard to make cheap.
Reactions that release excess energy as charged particles, though all harder to actually do, leave you with charged particles that can be directed by electric or magnetic fields and can be used for direct enerergy conversion.
Yes solar requires a lot of surface area, but fusion power is just not looking like it will be anywhere near cheap enough for the real estate savings to matter.
At the moment fusion is obviously not cheap but no one is planning on using the technology in its current form for actual power generation. The processes involved will all get more efficient and given the astronomical upper limits of energy output from fusion it doesn't take a big stretch of the imagination to think that it will eventually be preferable to solar and wind power. There's no guarantee that will happen but hopefully this breakthrough will trigger more investment and momentum to make it a reality. I also want to add that I'm very pro solar and wind, especially in the short term.
So in sum, the advantages are (1) dependability, (2) safety, and (3) small footprint.
Got a source for this? The only time I've seen this has been political talking points that had no backing.
Damaging that has got to be a lot better for the planet than coal or nuclear.
I grew up by the desert, and I don't know why people think it's dead. There are some extremely fragile ecosystems there.
Sounds like you're talking about a single country?
I'm talking about when I've driven through the Sahara (West and East side), Namib, Simpson, Great Sandy, Gibson, etc. etc.
There is a HUGE amount of land on earth for things like solar and wind.
Fusion energy has a theoretical max that’s orders of magnitude higher.
Wind+solar is the path to decarbonization and sustaining our current world.
Fusion is the path to post scarcity. If/when we get scalable commercial fusion, it’ll be like the transition to oil - society will radically change, in ways we can’t predict.
Except this is also true for fission. So if fission has failed to transform society, why do you think fusion will?
I recommend you read up on the Gen IV reactor designs. They’re totally safe - meltdowns are impossible because of the way the reactor is built. If anything catastrophic happens, the reaction stops and can never get to a runaway reaction (physically impossible). Look up Gen 4 reactors. Those will be available before fusion even gets off the ground (and I’ll note that fusion has 0 reactors built so who knows what kind of safety issues actually come up when engineering theory hits the road).
Even Gen III reactors are fine to put up everywhere (20x margin over Gen II) and Gen III+ reactors continue with the theme of adding passive safety measures that would prevent accidents like Fukushima and Chernobyl. Critics who rate any possibility of accident as unacceptable will never be pleased but that’s not a reasonable position to take because nuclear energy isn’t built in a vacuum and global warming and existing coal power poses a significantly higher threat and renewables and batteries simply can’t scale no matter how hard we believe.
Fukushima and Chernobyl were Gen II designs which do have a cost advantage and EVEN WITH THOSE ACCIDENTS those designs are safer than existing coal and LNG power plants we are fine with having all over the place (nuclear is slightly safer than wind). Even Gen II designs built today are a fair bit safer than Chernobyl and Fukushima. Fukushima also ignored many and repeated safety warnings from internal and external reports although critics will generally point to this as a general criticism against all reactors (even though Fukushima still failed comparatively harmlessly all things considered).
Even with all of that, the death rate per kWH generated is drastically safer than coal and on par with wind and solar. Also construction costs tend to go down when the regulatory environment doesn’t inhibit building reactors due to political fears that aren’t grounded in the actual engineering.
I’ll also note that China is building many many nuclear reactors and Russia is also following suit. So from a competition/national security perspective, China and Russia both have access to significantly more clean energy and more energy independence than we do.
Look. I understand there are problems with fission reactors. They remain the only feasible way to generate nuclear power in the next 60-100 years at scale. Yes there are downsides and risks. However there’s one big upside vs fusion: it exists. It’s possible to build these plants now without physics and engineering breakthroughs we haven’t made yet. The advantages of fusion are safety, nuclear waste management, theoretical proliferation concerns. There’s no reason to believe construction costs will be significantly lower. Even if they are, we’re not even close to the first real commercial power plant even with this achievement as impressive as it is from a progress perspective.
> Look. I understand there are problems with fission reactors. They remain the only feasible way to generate nuclear power in the next 60-100 years at scale. Yes there are downsides and risks. However there’s one big upside vs fusion: it exists.
If you re-read the original comment, it supposed that fusion exists. You can't criticize something in development for not existing and use that as a point against why it won't be beneficial. That's circular reasoning.
> The advantages of fusion are safety, nuclear waste management, theoretical proliferation concerns.
Yeah, just nuclear waste management. No big deal.
> They remain the only feasible way to generate nuclear power in the next 60-100 years at scale.
You absolutely cannot predict with that level of certainty over 100 year time scales. You severely underestimate how much we can achieve over timescales as long as that.
Renewable generation + storage gives a system that's capable of meeting base load needs, just as nuclear generation does. Cost comparisons among base load-capable technologies is a better way to evaluate the economics, IMHO.
Also, you could eventually put one on a spaceship or other planet. For that Star Trek future.
This has the feel of those “water discovered on Mars for the first time ever” headlines.
It comes to reason, the politicians are going to produce only 0.00001% of consensus.
Conclusion: things are looking rather bad. We are not going to achieve Civilization Survival, much less Singularity Ignition.
My suggestion: highly educated Homo Sapiens may not be the right course. There is a proven way of saving the planet which, by virtue of its remarkably sustainable intellect, we should be investing more on: koalas.
Anything you read on the internet, explaining any advanced scientific concepts like fusion etc... take it with a huge grain of salt.
We are all parrots.
I’m sure they would agree with what I said when they scroll through the comments.
I would not want to wander into HN comments section if I am doing any kind of divergent innovation, challenging the limits of what's technically possible. People here just parrot the status-quo as the absolute truth. If that was the case, humanity would have made zero progress.
Some nerd in some quiet corner, working hard in disbelief of the rest of the society, is the one changing the course of history. Not the ones, parroting established textual truths. There is GPT-3 for that.
"LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output"
From newscientist, the same info followed by a rider:
"generated a power output of 3.15 megajoules from a laser power output of 2.05 megajoules – a gain of around 150 per cent. However, this is far outweighed by the roughly 300 megajoules drawn from the electrical grid to power the lasers in the first place"
In other words: it's a net-positive output for that reaction, not the whole process, there is still a lot of work to be done before you and I exchange comments on a server powered by fusion energy in homes powered by fusion energy.
> in much the same way that the 3.15MJ of output won't convert to 3.15MJ of electricity as the conversion is not loss less
...and very much touche! That's a good point. But I do feel the overall loss should have been made clear and distinct from the gain in one part of the whole. Gross vs net perhaps?
That's an important piece of information - the thing is gigantic!
> This is indeed a promising and exciting result, but we need to remember that this does not take into account the energy required to run the lasers that confine the reaction and other inefficiencies and losses.
https://www.sciencemediacentre.org/expert-reaction-to-fusion...
It's still entirely possible that we will not see a fusion reactor in production within our lifetimes.
We don't have a commercially viable technology here yet, but we've proven that it's at least viable for the part that needs to produce energy actually can produce energy.
As I understand it, now we start down the road of improving the ratio and optimizing the process.
FWIW, from my lay perspective it seems like the research NIF is doing is significantly smaller scale than the work being done elsewhere. That's a good thing in this case, because the output:input ration - the Q - seems to increase exponentially relative to input power.
While this is great progress, I feel that it's important to have the full picture. There's a lot of "fusion reaction breakthrough fatigue" stemming from the misunderstanding that fusion power isn't a technology that requires a singular breakthrough.
There are many breakthroughs required to get to fusion powered energy, and this is an important one (worth celebrating) on a long road ahead.
So this is the first time that a fusion reactor has been net positive for energy production
Other approaches attempt to create a continuous plasma where fusion can occur confined in a powerful magnetic field, and heated by radio waves to get it going. So there's always fusion happening rather than in short bursts.
Tokamaks (the other approach) are more like jet engines in that they sustain burning. But currently the burning in tokamaks requires more energy than it generates.
The Inertia based fusion works by providing the heat/energy with lasers, so the fuel would have to be replaced continuously.
Edit: Taking the internal combustion metaphor further, I'm imagining these connected in a circle. The grid is the starter motor to power the first laser, then each active chamber powers the laser on the next one (probably by capacitor not directly). Thus the energy production moves around the circle with each chamber being flushed and refilled before the laser powers back on. How far off is that image in my head? I've never actually seen it described
There are lots of other problems that NIF also studies that boil down to "what does this do when we squish it" that have nothing to do with fusion or energy production. Aside from the weapons program applications, there are experiments that take place there in materials science, understanding extreme environments ("what do these elements we believe sit in the core of Jupiter act like at those pressures?"), etc.
TLDR: Think of NIF as a lab for energetically squishing things. It's not a power plant, it's not a prototype for a power plant, it's not a pre-prototype for a power plant, etc. It's a lab for basic physics research. It's about as close to being a prototype for a power plant as a test tube in a lab full of hydrocarbons is to being a prototype of an internal combustion engine.
Nuclear-fusion lab achieves ‘ignition’: what does it mean? - https://news.ycombinator.com/item?id=33971953 - Dec 2022 (82 comments)
Two threads from before the announcement:
Fusion energy breakthrough by Livermore Lab - https://news.ycombinator.com/item?id=33945863 - Dec 2022 (755 comments)
Secretary Granholm to announce major scientific breakthrough by DOE [video] - https://news.ycombinator.com/item?id=33968357 - Dec 2022 (160 comments)
How much will my electric bill be reduced?
> How much will my electric bill be reduced?
Running costs and maintenance would also be high, the fuel alone is expensive (right now), and I’ve heard that wear and tear on parts of the reactors can be high so much of the housing for the reactor would need to be replaced with time.
You’ve probably also got a small army of engineers running each one of these reactors you’ve got to pay.
All that said, the energy produced via fusion is EXTREMELY abundant. I imagine with later reactor iterations (after supply chains have been setup and electrical transportation routes upgrades) electricity could become very cheap even relative to renewables.
This part gives me so much hope as we have understandings of what is theoretically possible, and in due time humanity reaches them. This gives me a lot of hope especially in the fields of curing major diseases and in longevity!
> Fission is currently the most common method of generating nuclear power, and it has been used in power plants for many years. It is a relatively well-understood technology and it can provide a large amount of energy with relatively little fuel. However, fission produces radioactive waste and the risk of accidents, such as the one that occurred at the Fukushima nuclear power plant in Japan in 2011.
> In contrast, fusion has the potential to provide even more energy than fission and it produces very little radioactive waste. It is considered a safer and more sustainable source of energy than fission.
Excellent milestone for humanity nonetheless
That's amazing.
The 2.05 MJ put into the reaction includes the laser power supply then, it would seem, unless they are bad at press releases. But 2.05 MJ is not a lot of power.
Still even if it's just the beam we are at an energy positive which is still great news because it mean the fundamentals are working.
Still other issues though, the biggest in my opinion are an effective way to produce Tritium and energy extraction.
It's scientifically interesting because a self-sustaining reaction (until the fuel was consumed that is) was achieved in a lab setting (as opposed to in a hydrogen bomb). There might be fusion plasma data in there that are of importance to more serious attempts at actually building fusion reactors.
NIF uses notoriously inefficient lasers. They lase fine. Just not efficiently. From what I've seen, that 200 MJ would be closer to 20 MJ with modern equipment.
Still a gap! And there is still making the fuel, making and replacing the reactor as well as collection losses. But we're within two orders of magnitude of system break even, which is closer than we've ever been.
Armchair scientisting aside, this news seems like the most exciting news over the past few years - a great way to end this year (/pandemic). We are far out from a production-ready thingy, but if it took decades for brilliant scientists to conjure up this initial clunky toy thingy, I am sure an army of scientists/companies would work at building the real thing much, much faster: we had only a freaking 8086 not 30 years ago!!
We have the basic blueprint from government funded research no less.
Let's add some words. The output energy is electromagnetic radiation and heat. When they do make a conversion to usable energy (electricity) there will be conversion losses.
On the input side, they are measuring laser energy. The lasers are not very efficient so this overlooks a bunch of losses on the input side as well.
They are probably 100x away from real energy gain, and the facility isn't even designed to be used that way.
Never the less, it is a milestone along the way.
I imagine that power dynamics would change drastically, but I have no clue, really.
I understand that's still far away, but are there any articles/discussions on how large scale fusion-generated energy would change the world?
* The middle-east no longer becomes a strategic region. Wealthy regimes see their income disappear. The US has supported Israel as a strategic check in the region, but with oil losing its value the US no longer needs to fund Israeli security. We are likely to see skirmishes if not major wars, but this time it's over empires in decline, rather than empires with strategic resources.
* Texas' GDP declines substantially creating significant unemployment. Will government scape goat immigration and create further social problems, or invest in leading the transition creating a new wave of energy industries.
* Developing countries swiftly raise their standard of living as cheap energy is brought online. No idea what this ramification would be.
- Yes the efficiency of the laser is poor and modern tech is more efficient, but not enough to make it an energy producing process. The best lasers are ~50% energy efficient.
- This can only be maintained for short periods of time and the time to restart the process in long. Not only that, tritium is a rare isotope. These are probably the largest challenges to overcome.
- The energy is released in the form of high-speed particles, and there is no efficient energy capture process.
The significance of their achievements is overblown. Yes, they achieved ignition, but no it is just an incremental process towards commercial fusion power.
The pay off achieved by accelerating fusion development seems to justify almost any amount of spending. Is it worth going for it?
The most important subquestion for me: is there a sufficiently brilliant living scientist who has the technical ability, managerial skills, and integrity to be trusted to deliver? I wonder if this is the reason we haven’t already done it.
So much left to do. Capture that output energy. Streamline the machinery that produced the result. Do it at scale and efficiently.
But that's just engineering, as they say. Which is one thing we are pretty good at!!
[0]: https://www.llnl.gov/join-our-team/careers/find-your-job/0d6...
145k TC for Software Engineer. Better than I'd expect from a government job, although a qualified applicant could obviously make so much more elsewhere. And supporting the needs of a bunch of PhD's doesn't really sound fun.
Yet I’m concerned that shortly thereafter, the giant robotic laser death spiders will destroy entire cities. This might also be be before we’ve built the arcologies to launch into outer space to escape the giant robot laser death spiders.
you probably meant "fusion"
> My father still finds it novel that he basically gets to wear Dick Tracy’s watch.
Well, except for the front-facing camera, but that's trivial to add at this point. And as a 50 year old, I agree. I feel like being incarnated in '72 has gotten me ethereal tickets to the greatest technological expansion/brouhaha in all of human history, and I don't know what my soul did to deserve this pleasure. Everything I've been into as a kid "before it was cool" has absolutely exploded: Computers, electronic music, gaming, telecom, AI, green energy/electric cars... but also science, medicine, etc. are making tremendous progress (I'm down 35 lbs thanks to Mounjaro, a brand new drug). Hell, even that weird side interest in UFO's (one of the first sections of the library I discovered as a kid) has paid dividends with the USG finally admitting they're real. BRB, I have to pinch myself. Unironic "what a time to be alive"!
> giant robot laser death spiders
you should probably worry more about the silent airborne drone army suicide bombers first. (What was the movie that actually featured a scene with those, btw? I think it had Morgan Freeman? EDIT: Found it, thanks to those other technological wonders, Google and YouTube: https://www.youtube.com/watch?v=40JFxhhJEYk)
There will always be dangers with progress. Two steps forward, one step back. But I leave you with this. I asked ChatGPT to summarize this article as a sarcastic poem https://newsletter.mollywhite.net/p/everything-sam-bankman-f... and here's what it gave me, and I'm still chuckling about how awesome this is:
Sam Bankman-Fried talks a lot
But it's all just hot air
He tries to seem transparent
But he's just trying to repair
His reputation, once so grand
Is now as tarnished as can be
He's just a fraud, don't be fooled
By his attempts at publicity.
I haven't read Dick Tracy in a long time, but if it's still being made I bet Tracy's watch has been upgraded with a bunch of new features the Apple Watch lacks.
> What was the movie that actually featured a scene with those, btw? I think it had Morgan Freeman
It was specifically a SimCity 2000 reference.
I just hope we have enough time to see it implemented at scale (ie, powering entire states/cities/towns/municipalities, swapping infra in place).
I also hope the O&G industry doesn’t attempt to block this with fake science (ie, decades of climate denial, greenwashing via “recycling” campaigns).
In the presentation they mentioned they couldn't reproduce the results immediately due to the containment imperfections -- at least that was my understanding.
[0] https://astralcodexten.substack.com/p/your-book-review-the-f...
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.
> 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.
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.
Any advance in energy production or propulsion has a weapons counterpart.
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.
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.
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.
It's the engineering that makes nuclear weapons hard to do, not the knowledge.
for some reason, all the news articles are extremely misleading.
previous output ratio for this fusion method was something like 70%, now it is 150%. it's a useful improvement, but not a major breakthrough. the whole system still consumes 100x more energy than it produces. 100MJ of energy is needed to power the laser. the laser generates only 2MJ of energy that powers fusion. fusion generates 3MJ of output energy. so all the articles are saying "they put 2MJ energy and got 3MJ energy back". no, they put 102MJ and got 3MJ.
Also, the other thing most commenters are missing here is the remaining problems are incrementally solvable so we should see steady improvements in laser efficiency and pellet optimization going forward. this is even doable with VC money (which we have some now but not significant). in that sense it is a pretty decent development.
What is the timeframe for those lasers to light a bulb somewhere, vs the timeframe of those lasers killing someone on a battlefield ? (As in, how much of is applicable for the military?)
The lasers in question are mediocre for battlefield use. The consequences for the military are trivial, unless you're talking about 70 years from now when the US military is using fusion to power some of its military bases, subs or carriers.
At least the Nature article had a good ratio of actual information about the experiment, its limitations and prospect, as opposed to massive hyperbole from other commenters already popping the champagne as if the energy crisis was over.
This made sound grumpy, which, truth be written, I am.
(And, jealous, too, of course. I wouldn't mind a bit of actual success, once in a while.)
Or maybe the grunts working on the experiment know better, and are _also_ grinding their teeths at the PR effort ? Maybe _they_ also feel unsatisfied because they still haven't met their own goal ? I suppose nuclear fusion physicists must have imposter syndrome, too ? Who knows.
- js.
Energy output exceeding energy input produces a surplus of energy. That's a must and that's the breakthrough LLNL is announcing but le tme list the some of the known barriers to producing electricity:
1. How stable is the reaction? What failure modes does it have? While fusion doesn't have the same failure modes as fission does (eg Chernobyl) it could still result in significant damage to the container or even the facility;
2. What's the relationship between capex ("capital expendiutre"), lifetime, maintenance and power generation. An extreme example is if your power plant costs $50B with annual mainteance of $2B and a life of 30 years but only produces 100MW of power then even though the fuel is free it's not economical because those capex and operational costs have to be amortized over the life of the plant;
3. How available are the fuels? Of course hydrogen is abundant but most of it is protium (H1), which is not useful for current fusion research. Most of it is DT fusion, meaning deuterium (H2) - tritium (H3). Deuterium is naturally occuring (IIRC ~1ppm). Tritium is not. It needs to be bred.
4. What about neutrons? Neutrons create two problems. The first is energy loss. High speed neutrons are energy loss from your system. Inertial confinement (ie this result) tries to capture neutrons with a "shell". Older designs (eg ITER) use a tokamak, which is magnetic containment of a superheated plasma. Magnetic fields are great for containing electrons and hydrogen nucei because they're positively charged. Neutrons obviously have no electric charge so just escape. The second problem is the damage these neutrons cause (ie "neutron embrittlement").
5. How do you convert that energy into power? Nuclear fission, for example, heats water into steam that turns a turbine that generates electricity. This isn't particularly efficient and greatly adds to the costs. It's another system that needs to be maintained. "Direct energy conversion" would be the holy grail here but that's all very theoretical at this point.
Once you start adding up efficiencies in the different stages of electricity generation you have to do significanlty better than simply exceeding power input.
It's a notable achievement but as the release says, viable power generation is still a long way away (ie decades).
Fission can always melt down.
However, the way they're realizing it by shooting a fuel pellet with lasers is unsustainable and impractical IMHO.
Hohlraums are expensive but not millions of dollars. This 2004 report puts the cost at about $2500 each (still far too expensive for a power plant of course) while examining ways to get them under $1 each.
"Cost-Effective Target Fabrication For Inertial Fusion Energy"
What is meant by this?
In addition, computer simulations are often used to test the effects of a nuclear weapon, such as the predicted fallout and atmospheric effects. These simulations are based on data collected from previous nuclear tests as well as theoretical models.
When I ask ChatGPT it says:
"fusion is not directly related to nuclear weapons or the maintenance of a nuclear deterrent"
>fusion is not directly related to nuclear weapons or the maintenance of a nuclear deterrent
ChatGPT is wrong in this case. Fusion occurs in hydrogen bombs i.e. nuclear weapons
What ever it been fueled with, knowledge wasn't created at an individual's birth, it's an accumulation of a collective and shared effort
The point i was trying to make in my post is; it always starts from the people, for the people to continue, for the people to achieve a civilizational ascension
If we build the means to generate infinite energy for free, then we'll have to ask ourselves if giving that much power to the individual a safe endeavor, or if we should make sure the prospect is for the collective to ascend
Thanks to this achievement, many will learn from it and acquire knowledge to pursue that goal, would it be the case if it was a solo for profit effort? i doubt it greatly
The open source tech industry thrives because it's a collective and shared effort, funding issue persists but that's due to us, individuals, living civilization's transition, it'll be a solved problem shortly
What's the alternative? Every collective effort is a series of individual efforts.
I checked the Wikipedia entry, but the only reference it maintains for the Smithsonian having helped the Wright brothers is that they apparently gave Wilbur an award in 1910, after having tried unsuccessfully to steal credit from him for building the first heavier than air flyer. Somehow I doubt that's the kind of government contribution to innovation to which the previous poster intended to refer.
Wilbur Wright asked for the Smithsonian's aeronautical research. They still have the letter. The very Wikipedia article you're referencing, in the exact paragraph you're talking about, contains the words "Orville Wright, whose brother had received help from the Smithsonian when beginning his own quest for flight." https://en.wikipedia.org/wiki/Wright_brothers#Smithsonian_fe...
Sure, the Smithsonian people were assholes about it. That doesn't negate their contribution to the Wright brother's work. Incedentally, in modern timesif you visit the Air and Space Museum you can see the exhibit where they own up to the shabby attempt to promote their late leader over the Wrights. They cover the feud pretty thoroughly -- including having both aircraft.
Please correct me if I'm saying something stupid.
If you toss a solar mass of water into the sun it just becomes fuel.
So, could a fusion reactor, when efficiency is improved, use water as fuel?
That said, there are two pretty important caveats about how big a deal it is macroscopically:
1. In order to have useful fusion power, we'd need at least another order-of-magnitude or so energy out compared to energy in. Maybe, depending on how optimistic you are about the ability to capture that energy and efficiently feed energy in, closer to two orders of magnitude.
2. This is from an inertial confinement approach to fusion. Unlike the magnetic confinement approaches that we often hear about, this approach doesn't really create a continuously hot, spatially constrained bit of plasma that can then be used to heat things up -- it produces more like a small but intense explosion. There are real doubts about whether you can, even with very favorable energy-out ratios, industrialize that into an actual power plant. It's more challenging to harvest energy from an explosion than it is to harvest energy from a bunch of plasma flowing in a circle.
Thank you, that is the kind of caveat I was expecting.
The caveat on caveat is that historically explosions (piston internal combustion engines) were developed before continuous burning (jet turbines).
So many questions. Pardon my ignorance.
People said the same of nuclear and here we are.
Sci-if authors have been talking about both solar and fusion for years, and now solar has been industrialized why wouldn’t we be excited to see progression in fusion?
That's the best outcome you can think of as a result of possible free energy?
Why are people optimistic that fusion won't have the same kind of problems, such as new plants being too expensive to build and old obsolete plants being too useful to decommission?
If you can eliminate or reduce the need for armed guards and mountains of red tape, this has the potential to solve many of fission's problems while providing the same benefits (unlimited zero carbon power with dirt cheap fuel).
There's no guarantee that these issues will be surmountable.
But fusion largely avoids the fear association with past fission disasters and fears about nuclear waste. This is a non-trivial political problem in many parts of the world, especially much of Europe. If fusion becomes economical (big if) and the differences between it and fission are well communicated it might be easier for the world to swallow.
I think visions of a 100% fusion world are fairly pie in the sky. Most of our energy most of the time will probably come from already viable renewables. But renewables cannot offer consistent baseline power all day, year-round, in every part of the world. We need either huge breakthroughs in storage, or carbon-free baseline generation. Economical fusion if it were achieved could offer that without some of the most politically difficult drawbacks of fission.
I'd probably still bet the farm on renewables + storage though, at least for my lifetime.
Fusion removes it.
So perpetually 10-25 years away at all times?
Beware science packaged as press-releases.
This seems unnecessarily partisan to mention
> This historic, first-of-its kind achievement will provide unprecedented capability to support NNSA’s Stockpile Stewardship Program and will provide invaluable insights into the prospects of clean fusion energy, which would be a game-changer for efforts to achieve President Biden’s goal of a net-zero carbon economy.
That is his administration's goal, and it's the directive that DoE is working under during his presidency.
Unless you have another party in mind that's been vocally championing a net-zero carbon economy?
Sincerely, a Biden voter
That is debatable.
"The Department of Energy is pleased to announce the successful achievement of fusion ignition in our latest experiment. This breakthrough marks a major milestone in our pursuit of clean, limitless energy.
Fusion, the process by which atomic nuclei combine to release vast amounts of energy, has long been considered the Holy Grail of energy production. It has the potential to provide an virtually limitless supply of clean, safe energy, without the harmful greenhouse gas emissions or dangerous waste products of other forms of energy production.
For decades, scientists and engineers have been working to unlock the secrets of fusion and harness its power. This has been a challenging and complex endeavor, but we are now closer than ever to achieving our goal. The successful fusion ignition in our experiment marks the first time that this process has been achieved outside of the core of a star. This is a significant step forward in our efforts to harness the power of fusion and bring it to practical use.
We believe that fusion has the potential to revolutionize the way we produce energy, and we are committed to pursuing this technology with all of the resources at our disposal. In the coming years, we will continue to conduct experiments and research, with the goal of developing a fusion reactor that can provide a stable, reliable source of energy.
We are extremely proud of this achievement, and we will continue to work tirelessly to develop this technology and bring it to the world. This is an exciting time for energy production, and we are confident that fusion will play a major role in our collective future. We are grateful for the support of our colleagues and partners in this effort, and we look forward to continuing to push the boundaries of what is possible."
If you don't like nuclear for these reasons, you'll probably hate fusion.
However, those high energy neutrons do a ridiculous amount of damage to the structural materials, and if there are constant outages to swap and repair components, I don’t see an easy way of making energy economically.
Here's something talking about an actual fusion reactor:
"While the radioactivity level per kilogram of waste would be much smaller than for fission-reactor wastes, the volume and mass of wastes would be many times larger."
and
"To reduce the radiation exposure of plant workers, biological shielding is needed even when the reactor is not operating. In the intensely radioactive environment, remote handling equipment and robots would be required for all maintenance work on reactor components as well as for their replacement because of radiation damage, particle erosion, or melting."
https://thebulletin.org/2017/04/fusion-reactors-not-what-the...
I met a physicist who had written a paper in the 1980s about a fusion reactor that used the high energy neutrons from D-T fusion to breed ²³³U from ²³²Th, around the time that people were losing interest in fast reactors. The reactor itself might not be a profitable source of energy directly, but the fuel it produces would be useful in thermal fission reactors.
Fusion will be attractive as a neutron source long before it is attractive as an energy source, in fact there are many kinds of neutron generators already in use that use fusion.
The waste from fusion will be different in character from fission. Unless you are trying to make TRU you are not going to have any transuranic waste. Most of the real danger from fission products is in isotopes of a few elements in a particular range of atomic number, particular Cs and I.
On the other hand, a D-T reactor is going to have a lot of T around and T is hard to contain since hydrogen likes to infiltrate between the atoms in metals. The flux of neutrons on the first wall is going to be absolutely brutal, how bad the activation is will depend on what exact materials you're using, but the difficulty of the situation is such that you might not have much of a choice.
Throw lots of money at something when you need it to happen and then it will happen. Or have control over the technology and don't let it see the light of day until it benefits you financially and makes your enemies lose their main stream of income. I truly applaud this timing and will err on the side of conspiracy rather than coincidence reading more about this "breakthrough".
It would be coincidental timing, if the most breathless headlines were actually true. But in reality we're still decades away from commercially viable fusion power generation. A fusion energy gain factor of Q=1 is little more than a psychological hurdle. Imagine you have a process that consumes 1 gigawatt of power and produces 1 gigawatt + one additional watt of power; that's Q=1. And it's certainly not commercially viable.
Years later I saw a picture of an Iranian woman holding a sign that said "Nuclear Power is a Human Right" and thought... She much be a LaRouchite.
I wound up voting for Diane Sare, another LaRouchite, for US Senate in New York this year even though I know they're a coercive organization like the Scientologists or the Longtermists and I disagreed with her position on Ukraine -- we had a really sad ballot this year since they made it much harder for 3rd party candidates to get one and she was the only one.
LaRouchites are the only people left who want to stamp out the Beatles but they are required to not only listen to only classical music but are only allowed to listen to Brahms and anything older. If I ran into a LaRouchite and wanted to make them squirm I would talk to them about Debussy.