Nuclear fusion: WEST beats the world record for plasma duration
514 comments
·February 18, 2025alkonaut
nkrisc
The issue with that is how to direct the energy back to Earth, and then collect it. If you can’t direct it and it radiates in all directions then only a tiny fraction of the produced photons will reach Earth. Then you need to collect those photons in order to do useful work, otherwise they will just heat the earth. If the distance needed to remain safe is greater or less than geosynchronous orbit, you’ll need collectors all over the Earth as they won’t have constant line of sight towards the source and experience a “nighttime” of sorts. There is also the issue of atmospheric effects, such as high densities of moisture, absorbing or scattering the photons, reducing the efficiency of the collectors. So it could work, but the effective maximum capacity will always be quite limited and the overall process highly inefficient relative to the total fusion energy produced.
rob74
Actually you don't want the transmission process to be 100% efficient. If you really captured all the fusion energy transmitted (or even just the small part of it reaching Earth), all sorts of people would complain, trust me! But fortunately that fusion reactor has more than enough power to go around...
nkrisc
If only it were smaller and closer. We could make it smaller by using a force other than gravity to compress the matter. Perhaps a very strong magnetic field? If it was strong enough you’d only need a fraction of the matter.
tehbeard
> But fortunately that fusion reactor has more than enough power to go around...
"All the energy we could ever use, forever and forever and forever."
"Not forever,"
_Algernon_
They wouldn't complain for long though
huijzer
How about we use solar panels to collect that energy? And then we add batteries to fix holes in supply when the panels can’t see the power source.
belorn
That sounds great, but those batteries are both too expensive right now and not available. People choose the cheaper alternative which are to use thermal energy where they burn gaseous hydrocarbons when the panels can’t see the power source. When the time and price is right we may stop building new such thermal power sources, but for now we can define them as the current best choice and even call them green since everyone has the intention to replace them in the future some day.
alkonaut
I think you are on to something here
Someone
> The issue with that is how to direct the energy back to Earth, and then collect it.
‘Simpler’: move earth to where the energy goes: https://en.wikipedia.org/wiki/Dyson_sphere
jmward01
Maybe we can use the excess photons in another way? We could bio-engineer sunlight collection devices that would take in sunlight and use it to break apart CO2 and produce other useful materials. We could then spread them around the planet to use the excess photons in a productive way. We gain valuable complex molecules and break down CO2 so a win win!
nkrisc
Hm, it could be possible to engineer devices that use the excess photons reaching Earth along with environmental CO2 and H2O to assemble sugars and other carbohydrates. Depending on the specific reactions, we could even end up with O2 as a by-product, which would be additionally useful for us.
Craighead
[dead]
hghid
There may also be a side business selling skin products to protect people who may be exposed to the radiation from this new reactor. Possibly people may even choose to vacation in areas of elevated radation, as it is likely to be warmer. Interesting...
robertlagrant
And another side business selling tanning beds.
AnthonyMouse
If you only have one of them then the photons would only be available on that side of the earth at any given time and the other side wouldn't have power, but two of them would confuse the animals and disrupt everyone's circadian rhythm and then you'd have to deal with the three-body problem. Even the reactor-facing side would also have issues with the photons not getting through when it's cloudy.
alkonaut
The photons will also create heat and that heat can be used for useful work at any time, even when there are no photons hitting that side of the earth. For example it will evaporate water which will later condense into rivers, where you can put turbines. So it's a kind of fusion power, but less direct. Pure science fiction, of course.
AnthonyMouse
The energy density of gravity-based storage is very low, so it could work in places where you have mountainous terrain and a lot of cheap land, but what do you do after the sites suitable for it are already in use? To make that work you'd need a scalable storage technology with a low enough cost per kWh of capacity to economically scale to multiple TWh of storage in case it's cloudy for an extended period of time.
For example, if you could make batteries at a price of $115/kWh, the cost for enough capacity to sustain the US power grid for a week would be around 24 trillion dollars, and that's just for the batteries and not any of the associated electronics or the land or the photon collectors themselves. It seems like to make your plan work you'd need a scalable storage technology with a significantly lower cost per kWh of capacity.
corimaith
Three Body Problems are only systematically unsolvable, you can still numerically calculate and manually move them with some algorithm.
palata
A huge fusion reactor at an enormous distance away... isn't that the sun? :-)
PhunkyPhil
It looks like ultimate goal of this is creating a self-sustaining fusion reactor approximately 1AU away from earth (for safety) and using photovoltaic arrays to absorb the energy... Ingenious!
ZeWaka
This truly is a miracle of modern science, something we could only accomplish in this day and age.
FilosofumRex
yes, exactly, no need for any fusion reactors in space. Collect space solar energy and beam it back to earth via microwave radiation.
Space solar is an old idea and the Soviets/Russians have worked on it since the 70's; and nowadays, like most other Russian inventions the Chinese are commercializing it. https://www.ft.com/content/2d43ed21-9f9d-4e90-a18b-ad46f0a47...
iamgopal
That's what OP was implying. Energy (..and its derivative global warming ) is just infrastructure and finance problem now onwards. Balancing grid, Moving power from sunshine area to non-sunshine area, storing some power at night, handling fluctuation all are more or less solved problem. Fusion is just research subject ( ..or for may be powering colony on mars ? ). ..... saying that, I hope our collective curiosity for fusion will take us to new inventions and space opportunities.
fransje26
> If we do the fusion in zero g then we have solved the confinement issue.
If me move the reactor close enough to the center of the earth, eventually we can get to zero g. We then also solved the confinement problem.
alwa
…is this an elaborate joke about solar power? And by extension, virtually all the energy that’s accumulated on the earth over the eons? It took me a minute :)
alkonaut
I thought it was obvious but apparently not. Sarcasm is only funny when not tagged with the /s.
alwa
I certainly got a laugh! And I agree about the /s. Chalk it up to this reader’s slow mind on a slow day!
In a forum where people credulously propose orbital platforms to “sell sunlight at night” [0], I find myself erring on the side of assuming seriousness…
spiderfarmer
A majority of the people on HN think there is an explicit no-humor policy. Judging by the fact that a lot of people here are genuinely confused when they come across something really funny, I can see why they try to pretend humor can’t insightful, useful or informative. It saves them from embarrassment.
deepspace
I find that many younger people have a hard time 'getting' sarcasm and irony when it is not explicitly pointed out. I wonder if it may be due to the prevalence of '/s' in online discussions, or if something else changed.
watt
Try building a structure around the fusion source: https://en.wikipedia.org/wiki/Dyson_sphere
mock-possum
beam energy down to the earth from space? My god man, did you learn nothing from Sim City’s microwave power plants??
alkonaut
I did some back of the envelope calculations for this and it turns out that almost all life will eventually evolve to have reasonable protection against it. Except in Australia.
janalsncm
> This was a 25% improvement on the previous record time achieved with EAST, in China, a few weeks previously
I applaud this nuclear arms race. 22 minutes is really impressive for a technology that’s always been “20 years away”. I think I will do a deep dive on the technical challenges of fusion.
thrance
Not to downplay it, but it's still only half as hot as would be required of a commercial reactor. Also this reactor had no mechanisms to recover energy or neutrons to breed tritium. Still impressive and encouraging.
XorNot
Right but that's what ITER is for. This type of research is to validate control systems which can be transferred to that project (i.e. prove you can do it, then prove its not machine-dependent).
amonon
I'm a layman, and so can't comment too specificaly. I found this Construction Physics article interesting, which was posted here some months back: https://www.construction-physics.com/p/will-we-ever-get-fusi...
AtlasBarfed
I'm glad the bear case includes the "will never be economically practical" which is my core criticism of fusion, even with "high funding".
I also didn't see anything about vessel irradiation, which also never seems to be discussed. I get it probably isn't as big a problem as solid fuel rod fission in terms of waste creation, and tritium breeding may help, but it still will be kind of the same problem with LFTRs: a reactor design will fundamentally need an ongoing reconstruction/replacement strategy due to the vessel irradiation and transmutation from high energy neutrons.
Feel free to correct me if this isn't as big a problem as I think it is.
api
The “20 years away” meme is stupid. There really are technologies that are possible but incredibly hard and require decades of sustained effort.
Cracking natural language comprehension with digital computers is an example from our field and it’s here.
slightwinder
> The “20 years away” meme is stupid.
No, it's not. It's just a legit illustration of somethings state of development on fundamental levels. It simply means "we have no f**ing clue how we can do this, but future..". This is different from something we have already solved, and you just need to throw money on it to scale it to whichever level you need it.
> Cracking natural language comprehension with digital computers is an example from our field and it’s here.
That's the point, everything in research is always x0 years away, until the breakthrough happens and it's finished.
api
> This is different from something we have already solved, and you just need to throw money on it to scale it to whichever level you need it.
We can already do fusion, and by every metric it is scaling. Triple product is increasing, etc.
Fusion does not become a viable source of energy until it scales beyond a certain point, but there is no "leap" between here and there that we know about, just better and better containment. We are descending a gradient, not looking for one.
If we had never managed to get fusion outside, say, hydrogen bombs, then I'd agree that we have no idea how to do it, but we have -- using many methods. Tokamaks seem to be the best one for scaling it so far, but there's other possibilities that I wish we would research more.
palata
I would debate the fact that LLMs have "cracked natural language comprehension"...
Not that it's not impressive, but LLMs do not "comprehend", for a start.
frenchwhisker
I see what you’re getting at but it does feel like goalposts are being moved, no? By and large we can ask a computer today a question and it will almost certainly spit back a sensible (!= correct) answer. We can ask what the words mean and ask it to translate it to other languages, and we can have a conversation.
throwawaymaths
what's your definition of "comprehend"?
riskable
Even more impressive would be when humans can actually comprehend LLMs!
anonzzzies
>Cracking natural language comprehension with digital computers is an example from our field and it’s here.
Exactly, there are experts in the field less than a decade a way who said 50+ years easily. And there we are.
nixonpjoshua
good one haha, the properly scary part of the other nuclear arms race is fusion too even!
niemandhier
Triple product (efficiency ) has increased faster than moors law for the last 50 years.
Still people make jokes about fusion research, some things just take time.
I recommend this excellent review of the even more excellent book „The future of fusion energy“
https://www.astralcodexten.com/p/your-book-review-the-future...
JumpCrisscross
> Triple product (efficiency ) has increased faster than moors law for the last 50 years
Fusion research progress is underappreciated. But Moore's Law is for an existing industry. Prior to that, it took 10 ^ 6+ improvements in various technologies to make computing possible.
Retric
Not sure what you mean by that. There was a bunch of computing technology long before photolithography or even transistors. And mores law was coined in 1965 when individual chips had far less than 10^6 transistors while the first one was made by hand.
darkhorse222
Indeed, I often think if I were transported to the past I would use rivers and dams to make logic gates.
throwawaymaths
Moore's law is self propagating: improvements in compute beget improvements in compute by improving the computers used to design compute devices. fusion, while in an impressive bootstrapping phase, does not get that acceleration until commercial break-even.
jjk166
Untrue on both counts. Moore's law is not due to improved computing power in the design process, it's due to an incredibly long series of process improvements which become easier to develop because of the increased understanding of the problems they are seeking to solve.
Likewise advancements in fusion beget advancements in fusion by increasing understanding of the challenges faced.
markhahn
moore's law is just the observation that chips are 2d: linear shrinks produce exponential benefit.
I can't see anything like a linear/square relation in fusion reactor design (even accepting that ML's premise of shrinks being linear in time is not a law, just something that sometimes happened, and sometimes didn't...)
kragen
Specifically they were able to maintain a tokamak plasma (presumably at fusion temperatures) for 1337 seconds, using two megawatts of heating. 1337 is not a joke; presumably the "leet" reading is coincidental.
Swannie
I assumed it was their target, and indeed a semi-private joke... but you make the case for coincidental. I prefer to believe it was by design :D
ReptileMan
With China spying around, you probably don't want to reveal the full potential of your technologies before you are sure that you will have permanent lead.
lanstin
That is not how science works best.
Bayart
EAST (Chinese) and WEST (French) are under the ITER umbrella. Showing your notes is baked in.
MobiusHorizons
The article says it was not fusion temperatures, and that they intend to get hotter in future tests.
kragen
I see, thanks! I missed that.
That makes it less impressive; any fluorescent-light tube can maintain a stable plasma for years, after all, without even magnetic confinement.
adamredwoods
Good technical intro to H-mode (high-confinement mode) for fusion reactions to work:
https://www.energy.gov/science/articles/science-close-develo...
>> In the H-mode, a calm edge without turbulence reduces how much heat and how many charged particles the plasma loses. This leads to a sharp increase in pressure across the entire volume of the plasma, including the core where the conditions that can lead to fusion occur. The reduced energy and particle losses also minimize damage to the material surfaces surrounding the plasma.
MobiusHorizons
Wouldn’t that make energy recovery from the plasma much more difficult?
philipkglass
Neutrons and photons pass through magnetic fields, so they always escape the plasma and provide heat that can be turned into steam. Keeping the plasma ions better confined doesn't impair energy recovery.
drdeca
One issue I see for applying prediction markets to things like “there is a commercially successful fusion power plant before the year 2070” is the long time until resolution. Now, of course, one can hope to sell your shares in “yes” or “no” 5 years from now, but there may not be enough liquidity?
Suppose we had one prediction market M_1 for “On January 1st 2070, resolves ‘yes’ if there has been a commercially successful nuclear fusion power plant, and otherwise resolves ‘no’”, and then another market M_2 that, maybe it resolves in 5 years as ‘yes’ if the price of M_1’s ‘yes’ is greater than 30%? Or… hm, that seems problematic because people could just buy a bunch of M_1’s “yes” right before M_2 resolves? Or maybe that’s a self-correcting problem because people could… no, still seems like a problem..
Well, what if instead of a prediction market about the future value of another prediction market, it was futures contracts for the shares in a prediction market? Like, the right to buy or sell shares in “yes” or “no” at a particular price?
So like, if you’re confident that the prediction market will assign probability p or higher on a particular day 5 years from now, then if you bought futures which, on that day each of the futures could be used to sell a share in “no” at the price (1-p), then… well, if the probability assigned to “yes” on that day is indeed p or higher, then the price of “no” would be (1-p) or lower, so one buy a share in “no” at a price less than (1-p) and then sell it at (1-p)..
Hm, issue there is one still needs to buy the “no” in order to sell it, so that doesn’t seem to really fix the “what if there is no liquidity in 5 years?” issue?
I guess one could spend 1 to create a share of “yes” and a share of “no”, and then sell the “no”, and be left with the share in “yes” which is ostensibly worth at least p, and then like, sell it a bit later when there’s more liquidity or something?
I probably don’t know what I’m talking about about this.
dmurray
You should look into options - you're describing various forms of options contract.
None of them solve this problem, though:
> Now, of course, one can hope to sell your shares in “yes” or “no” 5 years from now, but there may not be enough liquidity?
In general, if there isn't liquidity in the primary market you should expect the derivative markets to be even worse. You would use options not to find extra liquidity - and binary options on illiquid markets like you describe are indeed particularly prone to market manipulation - but to express very particular views.
> another market M_2 that, maybe it resolves in 5 years as ‘yes’ if the price of M_1’s ‘yes’ is greater than 30%?
Like this one - you should buy this contract if you really do want to make a bet the price will be over 30%, and you don't care much about getting a big payday if the price is 90 or keeping most of your money if the price is 29.
cladopa
The future value could be shared with the entire humanity.
For example, Bill Gates is going to die like everyone else and give most of the money away, like Warren Buffet.
They can spend a significant amount of money in life if they see nuclear fusion is possible, even if they do not recover the costs.
The only thing that is needed for this to happen is investors being confident that the money is not going to be wasted.
I personally know rich people that are betting a significant part of their wealth in fusion(millions USD) even when they know there is a risk that they will never recover the money.
serial_dev
Poor Bill Gates wants to give his money away, but he hasn’t gotten around to it yet. Why are we still pretending he is a philanthropist and not one of the biggest oligarchs of our time?
Izikiel43
Is he one of the richest people in the world?
Yes
Has given money in the order of hundreds of billions to charity?
Yes
Both can be true.
Peanuts99
As I understand it, most of his wealth is tied up in Microsoft stocks, so without collapsing the company he built, his hands are at least partially tied.
JumpCrisscross
> Bill Gates wants to give his money away, but he hasn’t gotten around to it yet
How much have you given away? If you just don't like rich people, say that, don't disguise it with false facts and moralising.
> Why are we still pretending he is a philanthropist and not one of the biggest oligarchs of our time?
My pet is both a cat and brown coated.
exclipy
I don't think a long pay-off horizon is a problem for this market. It the same as for shares in companies that don't pay dividends. What creates a price for Berkshire Hathaway (BRK/A) if owning the share never gives you anything in the form of dividend? It's because in the far future, you can be confident they'll have enough money in the bank that they will pay out. Maybe not in your lifetime, but you can sell to someone, who'll sell to someone, etc. who will eventually collect a dividend. The market is so abstract that that pay-off time could be infinity years in the future and still, the share still has market value today.
nradov
How would you define "commercially successful"? The first fusion power plants will only get built with huge government subsides. Some governments like China look at this as a strategic, existential issue and will pay whatever it costs to make it work. They don't like being dependent on foreign fossil fuel supplies that the USA could easily interdict.
tyre
I’m in the USA and don’t like being dependent on foreign fuel supplies!
I think there was (maybe still possible?) a real missed opportunity to pitch green energy in a national security or America First way. I don’t think the average republican voter wants us to be as tied to OPEC the way we are.
We could still product as much—or more!—oil in Texas while reducing our care for anything in the Middle East.
ajmurmann
The US is a net fossil fuel exporter at this point. In 2023 we inported $283 billion in fossil fuels and exported $361 billion (sauce: https://oec.world/en/profile/country/usa?yearlyTradeFlowSele...)
The real missed opportunity IMO is one of not communicating how well we are doing.
AtlasBarfed
Green energy has its own fundamental economic advantages over any petroleum energy generation. You know, barring grid and storage adaptation.
I believe the trend in Lazards is that storage+wind or storage+solar will drop under natural gas combined cycle this year or next year on a LCOE basis.
JumpCrisscross
> first fusion power plants will only get built with huge government subsides
This is true of every energy system ever.
spockz
I believe that was actually their point. To say that it is still a long way before a functioning fusion reactor will be build, let alone the first that will be built as commercially viable standalone without subsidies.
drdeca
I just meant “they generate power and sell it”, which, I realize now isn’t exactly what I said / what I said wasn’t exactly what I meant.
nradov
I mean I could generate power and sell it by burning antique furniture but that doesn't make it commercially viable. At some point any new power source will have to show a positive return on investment by some reasonable accounting measure.
thrance
At this point, just go to a casino. The last thing our world needs is more gambling and fruitless speculation.
pfdietz
Speculation with positive expected return is a good thing. So the question is, does fusion have positive expected return?
The world spends 10% of global GDP on energy, about $10 trillion per year. The world will spend something like a quadrillion dollars on energy this century, possibly more as the world gets wealthier and per capita energy use increases. A billion dollar investment is just one part in a million of that. Fusion doesn't have to be very likely to succeed to make such speculation worthwhile.
thrance
I was talking about prediction markets, not fusion.
drdeca
It’s not that I want to bet, but that I want a good probability estimate about whether commercially viable fusion power will be around by such and such date.
thrance
No, we'd simply get another financial product completely detached from any real economic value, of which we have plenty already.
What more insight could gamblers provide about nuclear fusion that expert physicists and engineers can't? Why and how would their predictions be more accurate than industry leaders?
Prediction markets are known to have an optimism bias when it comes to stuff like this.
rozap
I had no idea that Commonwealth fusion was already well into their construction of a grid connected plant. Apparently it might finally be happening?
I'm not sure how this works, how are they confident enough that they can make it produce net power?
sebsebmc
The location they have that's "well into construction" is SPARC, which is not intended to be a net power production facility. It will host their net gain demonstrator that they intend to have first plasma in next year and target a net gain demonstration in 2027.
ARC which they announced siting for and is intended to be their first grid-attached net power provider only just had the location selected so I don't believe its got much construction going on yet. The goal for that plant to be producing power is "early 2030s".
rozap
Ah, maybe not well into construction. But a friend of mine works with exotic materials and they are purchasing lots of things for ARC. Though I imagine these materials have a long lead time.
bufferoverflow
"The company plans to produce its first plasma in 2026"
They haven't even gotten to Q>1, let alone building a real power plant.
llm_nerd
For people more aware of the fusion industry, what is it that stopped the plasma at 22 minutes (or lower times in alternate tests)? Did they just stop injecting power to maintain the heat as they achieved their benchmark?
Is this something where it's on the precipice and small tweaks bridges from 22 minutes to basically indefinitely?
willis936
Tokamaks need the central solenoid to have a current ramp, so at some point you run out of voltage. You can turn that way down, but you get less plasma performance. You're traditionally limited by heat rejection capabilities of the vacuum vessel.
These are science machines to learn about plasma and increase performance of future machines. A real reactor involves a lot of engineering to handle the heat rejection problem (and turn it into a revenue stream if you're clever). In terms of the pulsed nature: not really a problem if you keep the duty cycle high enough and maintain sufficient buffers in your coolant to keep the turbines happily turning away.
topspin
I learned recently that another limit to plasma duration is contamination. As fusion occurs and high energy particles that escape magnetic confinement blast the toroid wall, ions of metal get mixed into the plasma and degrade performance.
I've seen photos of what the inside of experimental tokamaks look like after many cycles. Metal is eroded away and deposited around the chamber in interesting patterns. Unfortunately a image search isn't surfacing the images I have in mind.
HPsquared
Does that mean it's impossible to have steady-state operation? (And are stellarators different here?)
igiveup
Impossible with just the basic inductive principle of tokamaks, yes. Some years back I learned that you can keep the current going with microwaves, not sure about recent progress. You can also approximate steady state by reversing polarity of the warp - ehm - magnetic field regularly.
Yes, stellarators are different.
sounds
The current ramp in the central solenoid is used to set the plasma rotation direction. Theoretically this is more like Alternating Current, since there is not a fundamental reason the central solenoid couldn't ramp back down (and then proceed to ramp up in the opposite polarization). The existing plasma would need to be cooled and removed first, or some similar mechanism of stabilizing the torus again in the opposite direction.
I look at it as a large optimization problem at this point. Each part of the machine is workable but not yet sufficiently optimized to achieve profitable operation.
Olshansky
I keep track of nuclear related news.
An easier (more fun) version of this with some context is here: https://x.com/olshansky/status/1892069988707729614
blakehawkins
> x.com
I'm not clicking that shit
hans_castorp
You might be interested in:
* https://addons.mozilla.org/de/firefox/addon/twitter-to-nitter/
* https://addons.mozilla.org/de/firefox/addon/nitter
Cthulhu_
While that avoids directly engaging with Twitter, I'd avoid even indirect contact. That said, I'm confident that most Twitter enagement is indirect anyway, via embeds, screenshots, and services like these.
holoduke
[flagged]
fnordsensei
Musk is part of the administration that has threatened to take European territory by force. He's meddling in—and funding according to some sources—extremism in Germany.
Neither he, nor his administration, have been overly bothered to characterize themselves as friends of Europe, and Europeans are returning the feelings.
hans_castorp
> Noticed there is some serious anti Trump/musk campaign going on there.
And Americans should be very concerned about Trump's coup as well - because that's what it is. There is no level of sugar coating that can cover that up.
kristo
Your logic is that someone has to be brainwashed by woke European media to dislike musk or trump?
killerpopiller
As if right wing media have a legitimate place in a democracy. It was and will only ever be a vehicle for fascism. Maybe we Europeans enjoyed proper schools with history lessons and remember how Faschism played out last time? Besides following US media is enough to know what Musk is about.
moi2388
As somebody from Europe.. it is. The media is extremely biased and left-oriented. As soon as something is slightly more right leaning it immediately gets labelled as extreme-right here.
HelloUsername
Related?
Nuclear fusion: New record set at Chinese reactor EAST https://news.ycombinator.com/item?id=42917662 03-feb-2025
China's artificial sun burns for 1000 secs, creates record in fusion research https://news.ycombinator.com/item?id=42854306 28-jan-2025
adfm
From the announcement, "1,337 seconds: that was how long WEST, a tokamak run from the CEA Cadarache site in southern France and one of the EUROfusion consortium medium size Tokamak facilities, was able to maintain a plasma for on 12 February. This was a 25% improvement on the previous record time achieved with EAST, in China, a few weeks previously."
1,337-second burn.
ThePhysicist
Lots of leet scientists there, in all seriousness. CEA is my alma mater, though I worked on quantum computing, not fusion.
theultdev
how many more seconds did they push it to hit 133t xD
adfm
Considering it's fusion we're talking about, 1,337 seconds is about as arbitrary as 1,000 seconds. On a 24-hour clock, 13:37 is 1:37pm. 137 is the fine-structure constant or α. Who knows what they're actually capable of. A second more at this point would be pointless.
HPsquared
I wonder how much of an effect this kind of truly international (not in the same 'bloc') competition will have on budgets and speed of progress. Cold war tech race, etc.
It should be a good time to be an engineer.
dkkergoog
It's always a good time to be an engineer. These public comps are more recruitment and training. It's not like new discoveries are made during these events. It's partly a party for the industry.
belter
Still 50 years away...
dark-star
our physics teacher at school (late 90s) already joked that "usable fusion power is only 30 years away, for 30 years in a row now"
readthenotes1
A relative of mine told me that in 1960s they were saying fusion was only 10 years away
belter
Ok this was a terse comment, but so is a downvote. Please explain why is not 50 years away from first real industrial use. I am waiting....
zamadatix
As for "why not 50 years", even the pessimistic reports of that video have it at ~30 years. Besides, the point is "we won't really know a good estimate for when until it's already about to hit us in the face" not "we should just assume 50 years is a more correct guess than other ones".
As for the comments about votes, they aren't a measure of terseness either. The point is to bubble comments likely to result in curious and thoughtful conversation to the top while comments which will distract from that kind of conversation (combative, vague, distractly offtopic, or whatever else the reason may be) tend to get hidden away. Whether a comment is totally on the money or absolutely incorrect, how you present the conversation starter has a far bigger drive on what types follow-on conversation will appear. Here, that also strongly implies what types of votes will appear too.
Gud
https://news.mit.edu/2024/commonwealth-fusion-systems-unveil...
So according to the industry leaders, we will have the first 400MW plant within 10 years.
garyrob
"I am waiting..." was unnecessary.
ziddoap
Related: PBS Space Time just did a neat episode on plasma, focusing on what the requirements are for confinement, called "The Final Barrier to (Nearly) Infinite Energy"
archermarks
PBS Spacetime is great. Excellent, accessible explanations of advanced topics without feeling dumbed down or overhyped.
djyaz1200
I wonder if many of the stars in the sky are from groups that almost nailed containment and stability on their Tokamak.
zamadatix
The Sun consumes a mass equivalent of a mount Everest worth of hydrogen via fusion to shine for just an hour (or thereabouts, if I did my math right :)). For perspective, this amount of energy is more than enough to power the Earth's current electrical usage for over a billion years.
That's all before getting into how a containment failure doesn't imply "and then everything nearby just started a self sustaining fusion reaction". The confinement itself is a key part of what enables the conditions for the fusion to continue.
bezmiran
I am a plasma researcher, though not in the fusion field. Containment and stability are required on tokamaks to keep a plasma burning. Losing either of these will quench the reaction. The best way to control a plasma - magnetic fields, also causes significant instabilities, which is why fusion is so difficult.
slavik81
Could you elaborate on how magnetic fields cause instabilities? As a layman, it's not immediately obvious to me why that would be the case.
treyd
Because the plasma itself is charged and moves within the field, generating eddy currents which self-interact in complex and unpredictable ways. At a much much larger scale, the twisting of magnetic fields from convection within the sun causes sunspots and other phenomena around the solar surface.
cladopa
No. It just does not make sense from physical rules. Fusion only happens in a very high vacuum, at ridiculous temperatures, with very specific fuel, in the confined space. Just the cooling effect of having oxygen atoms there(in the plasma) stops the reaction, let alone touching anything so cold(millions of times colder and denser) as the walls or the outside gas.
Also stops immediately if no fuel is given.
thetoon
Naive question here : how do we expect to collect thermal energy from it if we can't allow it to cool even a little ?
XorNot
Neutron radiation doesn't get contained, and leaves the reactor easily carrying heat with it. That heat has to go somewhere, and so that's what we take energy from.
kadoban
You can extract heat, in fact you'd have to extract it or let it leak out somewhere. The whole point of it is that it generates more energy than you put in, so energy has to come out somewhere for it to maintain stability.
Gp is just saying that if you cracked it open like an egg (or just had a minor leak even) all that would happen is it would stop fusing. The room this happened in would be a bad place to be, but it's just going to start a fire or something, not destroy the world.
drdeca
Seems implausible. The fusion presumably wouldn’t keep going if it breached the walls.
Also, to be bright enough that we would see it from here as a star, I imagine it would require enough material that one might as well just let gravity do the job rather that use a Tokamak?
Maybe there are efficiency gains that are large enough that it wouldn’t actually require as much material as a star? I wouldn’t guess so though.
JumpCrisscross
> wonder if many of the stars in the sky are from groups that almost nailed containment and stability on their Tokamak
Different fusion systems. Stars fuse, in general, by statistically overloading the weak force. (The Sun is volumetrically about an order of magnitude less powerful than a human being. Like 200 to 1,110 W/m^3.)
In smaller volumes, e.g. on Earth, we have to break the strong force. This releases more energy, I think. But it also requires temperatures and energy densities far higher than that which stars produce.
Not sure if that strengthens or weakens your hypothesis...
XorNot
Strong and weak force don't come into it in either case. Fusion requires overcoming electrostatic repulsion, that's about it. The problem is the Sun is gigantic but it's fusion process is actually very inefficient. To make it practical on Earth we need more particle interactions, and thus higher temperatures, to make it Q>1
JumpCrisscross
> Strong and weak force don't come into it in either case. Fusion requires overcoming electrostatic repulsion, that's about it
You're wrong and right. Electrostatic repulsion is the barrier, and at its limit, defines electron degeneracy pressure. But the strong force is the ultimate source of energy of the reaction, and the weak force is important in stellar reactions.
The weak force initiates proton-proton fusion [1]. (We still struggle to empirically measure its cross section because it's so low. Weak force be weak.) DT fusion, on other hand, has to crack open the energy in those delicious gluons with raw temperature. This is why PP fusion occurs around 4 MK while DT fusion needs over 1,000 MK.
[1] Anthony Phillips' The Physics of Stars
If we do the fusion in zero g then we have solved the confinement issue. The problem is creating conditions for fusion in zero g. The simplest way would probably be aggregating enough material to a single spot that gravity itself creates conditions for fusion. But then the power plant becomes too energetic for earth so it has to be at an enormous distance away to be safe. And with that of course you have the problem of transmitting the power back to earth. But I think photons could be gathered at a safe distance from this fusion, to harvest it without having to be so close.