Their total power draw from the grid was 300 megajoules and they got back about 3 megajoules, so don't start celebrating yet.
Source: New York Times.
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'
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.
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.
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
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.
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.