Trouble_007 2022-12-11 18:36 UTC link

PaulHoule 2022-12-11 18:37 UTC link

The efficiency of the lasers is awful though and they will have to get at least 100x that energy yield for it to be a net power source. A lot of heat winds up in the laser glass and it takes it a long time to cool between shots so you are doing very good to make a few shots a day. A real power plant is going to need more like 10 shots per second.

Heavy-ion fusion has been talked about since the 1970s and it seems much more practical than lasers for energy production because the efficiency of particle accelerators is pretty good (maybe 30% or more) but it takes a very big machine, the size of a full powerplant, to do do meaningful development. Something like that seems to need about 100 beamlines because otherwise space charge effects prevent you from getting the needed luminosity. Given that you are going to need to protect the wall of the reactor and the beamlines from the blasts and also have a lot of liquid lithium flowing around to absorb neutrons and breed tritium it is hard for me to picture the beam quality being good enough.

There hasn't been much work on it since then. If I had $48 billion to spend I'd think a heavy ion fusion lab would be better than some other things I could buy.

mach1ne 2022-12-11 21:16 UTC link

Didn't they claim this already in 2013? https://gizmodo.com/breakthrough-the-worlds-first-net-positi...

monocularvision 2022-12-12 00:02 UTC link

It’s a real bummer to me that hype around fusion has faded so much because of the false hopes that this sort of thing barely registers on HN anymore.

acidburnNSA 2022-12-12 15:20 UTC link

After a few more major breakthroughs we'll be where fission was in 1942 after Fermi made the first man made neutron chain reaction. After that, we can see what a practical electricity producing plant looks like, and see how much people actually care about small amounts of tritium radiation.

At the moment fuel costs in fission are like 5-10% of total costs for a fission fleet. In fusion it could be lower, but that will not be any means mean the overall system will be cheaper.

We'll have to see the cost tradeoffs: fusion makes much less radioactive material per kWh than fission (but it still makes some) vs. simplicity. Fission is relatively trivial: just put special rocks in a grid and pump water over them as they pour out their star energy.

Progress is good and exciting, but I don't see any reason to think this will have major implications for energy systems anytime soon. Would be happy to be wrong though.

Disclaimer: I switched from studying fusion energy to advanced fission 16 years ago.

gjsman-1000 2022-12-12 15:22 UTC link

Well... if Nuclear Fusion becomes actually possible in a cost-effective manner, so much for the need to roll out solar and wind-based electricity, which looks very much like a 1st-generation modern green energy technology in retrospect.

I'm not complaining. If we do crack the code on Nuclear Fusion, if I was the government, my next step would be to figure out how to build so many reactors that electricity costs go to basically zero. If you can charge your electric car for pennies, even the most diehard gas-car fans won't be able to resist. Offering a better product attracts far more users than, say, trying to shame people for CO2 usage (more flies with honey instead of vinegar).

e1g 2022-12-12 15:38 UTC link

Good write-up to temper expectations at https://twitter.com/wilson_ricks/status/1602088153577246721

My TLDR (from a layman):

  * The output is greater than the energy *in the lasers*, but the lasers deliver 1% of the energy required to power them. Need 100x improvement to break even.
  * Converting the generated energy into electricity would cut the output in half. We need a further 2x improvement here, so it's ~200x to break even end-to-end.
  * The scientific equipment requires immense & expensive maintenance.
  * Plus the $3B facility around the equipment, that theoretically could deliver just 2.5 MW.

So we might be as close as 10-20 years away, as always!

chaps 2022-12-12 20:17 UTC link

“The Lawrence Livermore National Laboratory experiment shows that scientists can get more energy out than put in by the laser itself. This is great progress indeed, but still more is needed: first we need to get much more out that is put in so to account for losses in generating the laser light etc (although the technology for creating efficient lasers has also leapt forward in recent years). Secondly, the Lawrence Livermore National Laboratory could in principle produce this sort of result about once a day – a fusion power plant would need to do it ten times per second. However, the important takeaway point is that the basic science is now clearly well understood, and this should spur further investment. It is encouraging to see that the private sector is starting to wake up to the possibilities, although still long term, of these important emerging technologies.”

emphasis, etc

zaking17 2022-12-12 20:50 UTC link

Would anyone knowledgeable about the field update their priors about whether we’ll see commercial fusion in the next 30 years, after seeing these results? If not, is there a big milestone we’re waiting for? Or will fusion advancement be a slow grind with many small improvements over decades?

steve_avery 2022-12-12 21:02 UTC link

I have personally taken a tour of the NIF at Livermore. The guide was an old hand, who constantly remarked about the efforts of NIF towards "stockpile stewardship," ie the maintenance of the US arsenal of nuclear weapons. It seemed like NIF was all about the stockpile stewardship first, and fusion research was a secondary consideration.

The capability of the NIF to get positive energy from the energy that they impart on the Hohlraum itself is neat, but I constantly discount any milestones that Livermore/NIF report, because the inertial confinement approach has such higher barriers to commercialization than tokamak style approaches, that I just consign it to "boondoggle" in my head.

Yeah, the lasers could be 20x more efficient, and yeah, they probably could figure out how to pump 10s of targets into the chamber per second, but the energy extraction is just completely missing from the considerations. The engineering challenges are a whole 'nother level for NIF, a big barrier to usability.

di456 2022-12-12 21:27 UTC link

First flight 1903 Moon landing 1969

It took 63 years of progress in flight technology. Not counting earlier experiments and R&D time.

First fusion experiment was 1933 Fusion seems a lot more complex to a layman (me) than spaceflight.

Excited for what's to come

bnjemian 2022-12-12 21:38 UTC link

I'd be very interested to see the breakdown of input energy costs. Most notable is the raw energy cost required to power the lasers and control machinery in the experiment. But then there are other costs, all of which must be amortized over time for any real-world use case to exist. I say this because the journalists in this piece imply that net gain is simply based off of the amount of energy pumped into the experiment while it operated, but the total input energy would clearly be more than that.

On the extreme end, there's the energy cost of building the machine and engineering its components. For the vast majority of these, we can probably all agree that were a fusion power plant to be built, the net gain would fully eclipse these initial inputs fairly quickly. This may sound silly, but remember that the economic context where fusion so often sits is one that centers on renewable energy and sustainability. These costs do have to be accounted for.

On the other end, there's the energy cost consumables. For example, the deuterium and tritium fuel input into the device, which need to be purified (deuterium from water, possibly tritium from the atmosphere) or otherwise isolated (from what I understand, tritium is a byproduct from fission reactors and they serve as its primary source in scientific applications). It may well be that the energy cost of acquiring these consumables is fractions to fractions of a fraction of the energy cost of running the device, effectively constituting a rounding error. But I think when we're talking about net gain, a clear definition and accounting of the input energy required to run the experiment would be useful to communicate to the public.

I hope we see disclosure of these details with all the expected caveats when the peer-reviewed article goes to print and journalists have another feeding frenzy.

ibejoeb 2022-12-12 22:00 UTC link

Very encouraging to see at least some enthusiasm for this. This is the real way forward.

We can't just stop using energy. We can't buy our way forward with "carbon offset" fees. And, most importantly, we can't just redirect all of our environmental conservation efforts to eliminating energy use. Remember when we were going to save the rainforests? Don't forget why we called these "green" initiatives in the first place.

ChuckMcM 2022-12-12 22:29 UTC link

This is great! Why is this great? It is great because between magnetic confinement and inertial confinement approaches to fusion generation it is the FIRST one to demonstrate energy gain.

If you are programmer, think of it like your program compiled successfully for the first time. It means that all of the bits between you designing the program, the program being compiled, and the operating system recognizing it as a program, all did what they were supposed to. Of course your program probably doesn't do what you want it to yet, but you have validated a huge chunk of the "pipeline" between what you are trying to do, and doing it with the equipment you have. That is what this is, "hello world" for Fusion Physicists.

And the reason they are so pumped is that they have literally been told for DECADES that why they proposed to do "wasn't possible" (and by that I mean creating actual fusion through inertial confinement.)

Steps 2 - n look a LOT more like engineering steps than "can this even work" steps, okay?

jkelleyrtp 2022-12-12 22:37 UTC link

Very disappointed by the discourse in this HN thread. The same old quips over and over. "NIF is just a nuclear stewardship program", "it's not actually generating power", "fusion still 30 years away".

I think it's very clear, given the past year that NIF has had, that they are very rapidly approaching a point where we have the tech to "solve" inertial fusion.

https://lasers.llnl.gov/news/papers-presentations

Getting fusion right is done a magnitude at a time. Right now NIF is within 1 magnitude if they built it with modern laser tech. Many fusion designs are 10 magnitudes away or more.

Their most recent article has a ton of great data and next steps:

https://lasers.llnl.gov/news/magnetized-targets-boost-nif-im...

This includes

- Cryo-cooling the main target

- New alloys

- Magnetic compression of targets

The recent advancement that helped reach ignition (in the last article) boosted performance 40%.

The advancement between then and now: nearly 60%.

Within the past 6 months, NIF has nearly doubled energy output of the reaction.

Plus, if you know anything about fusion research, you'd know that energy outputs tend to scale non-linearly with energy input and size. This tends to be on the order of the power 3 or 4. Hence the existence of ITER.

NIF has uncovered some new science, closed the magnitude gap, and made it actually realistic for inertial confinement to be a feasible tech for a power producing plant.

rolenthedeep 2022-12-12 23:02 UTC link

To everyone whining about the lasers: who cares? It's an engineering problem, and there are already clear solutions and paths forward. Efficiency of the plant isn't what's being discussed in the announcement. Plant efficiency is an entirely separate problem that we already know about.

The exciting thing is that they've shown a fusion reaction in lab conditions which produces more energy than it takes to start it. Yes, the gain is small. It's nearly irrelevant to the amount of energy used to run the reactor, yes.

But it clearly shows that what we're trying to do is possible, and we've identified one mechanism that can initiate these reactions.

It's exciting. This is a great result that shows the science is progressing and beginning to finally show results.

Octokiddie 2022-12-13 01:21 UTC link

Some perspective from cnet:

> But, as with all science, it's good to be cautious and not overhype results yet to be fully analyzed. We have been here before, after all. In 2013, reports swirled the NIF had achieved this exact feat. It wasn't the case.

https://www.cnet.com/science/climate/a-fusion-energy-breakth...

AFAICT, the only thing that's been publicly confirmed is that announcement will be made tomorrow.

pontifier 2022-12-13 02:51 UTC link

I see I'm a little late to the discussion, but this is very similar to the patented Fusion device I've been proposing for several years here. http://www.DDproFusion.com

The main idea behind my reactor is to contain NIF like explosions in magnetic fields. I've been trying to get a test reactor built for a long time, and my plans have been hampered by a theft earlier this year.

A huge difference between the current NIF device and my proposed device is the speed of implosions and the strength of the field. While the NIF device must be re-built before every implosion, my device creates an environment where the implosions form as part of a harmonic oscillation. The ions are allowed to travel their entire individual cyclotron trajectories before they return to the implosion site... my target frequency was 2.4GHz, which is a useful frequency for direct conversion and COTS components.

panick21_ 2022-12-13 16:50 UTC link

Technically many of the issues with fusion might be solvable.

However, I see no reason what so ever why fusion would ever be cheaper then a GenIV fission reactor. I guess the advantage fusion has is that states actually invest serious money in fusion while fission is struggling to get funding.

The reason why I think fission will remain cheaper.

- Capital cost is less. A GenIV fission reactor is pretty low tech overall, in a non water based reactor the containment is mostly just a steel tub. Everything around the reactor, the heat loops, the turbine and so on will be mostly the same.

- Fuel cost. Fuel cost is already a small part of reactor cost, if we switch to a breeder the fuel cost is basically nothing. For Fusion, in the long term this is an issue and you likely have to breed new tritium.

- Operation cost. Seems to me that self regulating GenIV reactor should be easier to operate overall and there is much less complex technology involved that could break.

- Safty. A GenIV reactor that is passivly safe is already incredibly safe. Specially with a molten salt reactor, the radioactive chemical that get blown into the air, will just remain in the fuel salt and will remain in the reactor safety zone. A fusion reactor does actually contain radioactive material that could be dispersed into the air. A fusion reactor might still be safer, but the difference doesn't seem that big.

So really I don't get it, why would fusion ever be cheaper then fission?

That said, I'm not against research of fusion. I just wish more money was spent on actually getting GenIV fission reactors into real world uses. That would actually be a more viable solution to energy problems on the plant.

dang 2022-12-13 18:20 UTC link

Current thread, about the actual announcement:

US Department of Energy: Fusion Ignition Achieved - https://news.ycombinator.com/item?id=33971377

lambdatronics 2022-12-11 23:02 UTC link

Last time, they got something like 80% return on the laser energy input, now it's over 100% apparently. And, they had trouble repeating that last record, so people were questioning how meaningful it was if it couldn't be repeated. Now they've been able to repeat it & improve on it.

lambdatronics 2022-12-11 23:17 UTC link

Yeah, either heavy-ion beams or electrically-pumped excimer lasers seems like the path forward for the driver. Higher efficiency, higher repetition rate, possibly more robust. They also need to do away with holraums and switch to direct drive, to reduce target cost, ease alignment issues, and increase energy efficiency.

I don't hold out much hope for a practical, economical reactor from inertial confinement, but it's certainly exciting to see them achieve ignition & scientific breakeven, even if it's 10 years behind schedule. The one nice thing about ICF is that the energy gain shoots up dramatically once you cross the ignition threshold. That means they're arguably closer than tokamaks, even though both concepts need ~100x the demonstrated gain to get from where they are now to a workable reactor. (Ie, tokamaks have hit Q~0.3, need to get Q~30, vs ICF that has hit Q~1, needs Q~100).

Oxidation 2022-12-12 00:28 UTC link

It's not worthless research (not that you said it was), as it still validates various aspects of fusion energy and some of the engineering around it. And it's always been ahead of magnetic containment devices because they only have to keep the conditions for nanoseconds.

But NIF was never, and is not, designed to be a generating reactor, or even a prototype of a testbed. It's a weapons physics facility that happens to do some energy generating research sometimes.

That aside, hitting Q=1 (and be able to use the device again) in any way at all using any equipment is a major milestone that proves humans can get there. From that point, in theory, it's just engineering.

entropicgravity 2022-12-12 11:38 UTC link

Unfortunately large fusion is unlikely to ever be economic because the cost of solar/battery is coming down so quickly and is already in the 1-2 cents per kilowatt hour for the solar component. And costs will continue to drop.

Small scale fusion on the other hand would have a viable niche application at the poles, in the sea or underground or any other environment that is without sun or space.

boringg 2022-12-12 14:53 UTC link

I think that people are waiting to see the real announcement not the scoop with limited details. Let's see what the Granthom announces tomorrow. Tough to be excited about scoops with limited information and without the level of robustness of the accomplishment.

Izikiel43 2022-12-12 15:26 UTC link

Since you seem to be an expert in that field, what is your perspective on fission for the short term? Are smrs really viable ?

IMTDb 2022-12-12 15:36 UTC link

> even the most diehard gas-car fans won't be able to resist

They just won't have a choice; if we can provide a real alternative, we can just forbid gas car altogether. Just like we banned CFC to save the ozone when better alternatives were developed.

The main issue is that our electricity grids and production facilities aren't ready yet to sustain a mass shift to electric, so we need to ease in the transition. But the moment they are, there is no reason to delay any further.

eganist 2022-12-12 15:42 UTC link

It's still decades off but as I understand it, this was the hardest nut to crack. They got what, 2.5 megajoules out of 2.1 in?

I might be in the opposite camp as you but this is very much a "where were you when—" moment for me. I'm sure someone will pop in to disappoint me but I think the point is it's no longer a hypothetical exercise.

sveme 2022-12-12 15:53 UTC link

Even with such a breakthrough, cost-effective fusion would still probably be 50 years away. Why would you assume it to be super cheap right out the house?

augusto-moura 2022-12-12 16:21 UTC link

Much of fissions complexity comes from safety/damage management. Even after years of advancements we hear about some incidents and radioactive leaks every other decade.

Fusion is a much safer alternative both in incidents and fallout

Retric 2022-12-12 16:32 UTC link

Fuel is hardly the only advantage, the major issue with fission is the enormous costs of trying to avoid problems or cleanup after them. Thus 24/7 security, redundancy on top of redundancy, walls thick enough to stop aircraft etc. Fission is still by far the most expensive power source even with massive subsides and is only even close to economically viable as base load power backed up with peaking power plants.

In theory much of that is excessive but there is a long history of very expensive mistakes with massive cleanup efforts. The US talks about three mile island as the largest nuclear accident ignoring the Stationary Low-Power Reactor Number One that killed 3 people. All that complexity and expense comes from trying to avoid real mistakes that actually happened.

JStanton617 2022-12-12 20:34 UTC link

The loss just on the lasers is 100x (i.e. delivered power is 1% of the input energy). Add in a combined cycle effeciency of only 50%, you're looking at needing a 200x improvement to have commercially relevant "net gain"

zbobet2012 2022-12-12 20:51 UTC link

Yes, _but_ the problem of generating laser light efficiently has and is being solved for elsewhere. Which is why the NIF didn't focus on, or update their lasers. This is a major problem for semiconductor lithography for example, and receives literally tens of billions in investment every year and one which has lasers that are already 20x more efficient than the ones used by the NIF.

The real question in the experiments here at NIF was about whether inertial confinement fusion would work. This is very promising progress.

Also NIF spends a good portion of its time on weapons research, not fusion power so it's only been a recent focus.

dools 2022-12-12 20:59 UTC link

Helion tech seems to be interesting in that they use the electricity directly so avoids the costly conversion via steam/turbines etc.

billiam 2022-12-12 21:07 UTC link

No, not as always. The laser confinement mechanism works, it has been shown, lasers that are more than 20 times as efficient as these NID lasers are now available, so the improvement needed to scale and "commercialize it," whatever that really means looks more like 10x than 200x. In the world of fusion, that counts as really good progress. For one thing, perhaps a lot of the research money will move to lasers now.

kelnos 2022-12-12 21:15 UTC link

The NIF is using old laser technology. Current tech can get above 20% efficiency. Sure, that still means more improvement is needed, but 200x is probably an overstatement by an order of magnitude.

> So we might be as close as 10-20 years away, as always!

I don't really get the cynicism here. This is a huge milestone that's been passed. Maybe with this, we actually will be 10-20 years away. Or maybe it's more like 30-40, who knows. But this experiment shows that net-positive energy is actually possible to do with our current understanding and technology; before this, I believe much of the skepticism was based on a belief that it may not actually be possible to get more energy out than put in, at least not without technology that's significantly out of reach.

ak217 2022-12-12 21:17 UTC link

I'm not an expert but I've been following the field for a while. It's telling that negligible venture capital is pursuing this route to commercial fusion, and the only cheerleading for it comes from DOE lab press releases. That's because the NIF is a thermonuclear bomb simulator developed by a lab tasked with both thermonuclear bomb development and also developing a portfolio of civilian applications for its technologies. Even if the NIF were to break even on the entire power plant package in theory, harvesting energy from fast fusion neutrons is hard enough in magnetic confinement designs without them pulsing like a bomb as they do in ignition designs.

Meanwhile the VC money is quietly piling into tokamak and stellarator magnetic confinement designs, driven by high expectations from real breakthroughs in ReBCO tape manufacturing technology. These superconducting tapes can be manufactured like semiconductors and can develop magnetic fields that were previously impossible, which is a key manufacturability enabler in a design whose path to commercialization is far better de-risked overall. There are still concerns with the durability of equipment needed to capture the neutrons in these designs too, but ReBCO tapes were the real prior changer.

DennisP 2022-12-12 21:25 UTC link

Seems like energy extraction would be similar to other D-T designs: surround the reaction chamber with molten FLiBe or lead-lithium and run some coolant pipes through it.

kelnos 2022-12-12 21:28 UTC link

Personally I think fission power's failure is a political and marketing one. I don't agree that the waste disposal issues, or the safety issues, are quite the big deal people make of them. (Not saying there are no unsolved issues, just that the issues that exist are not significantly worse than those present burning fossil fuels, and are better in some dimensions. They're just different, and in some ways very emotionally so.)

I think it might be fine that fusion power may be more expensive in some ways than fission, as long as its reputation is kept clean (figuratively and literally). Market fusion power as the savior of humanity, and get enough people to believe it, and it'll be fine.

rawgabbit 2022-12-12 21:51 UTC link

What is your opinion of ITER? https://edition.cnn.com/interactive/2022/05/world/iter-nucle...

raylad 2022-12-12 21:56 UTC link

Not only that, but the capsules that are used for the experiment are expensive and difficult to produce. And you'd have to be continuously blasting new ones for each burst of energy you want to generate.

Taking those costs into account, being able to use this method to generate power seems really non-optimal.

leaving 2022-12-12 22:41 UTC link

You are correct. We need to control our own numbers at a sustainable level.

whiplash451 2022-12-12 22:52 UTC link

When your program compiles for the first time is usually when the real trouble starts.

serverholic 2022-12-12 23:11 UTC link

I'm getting really sick of the "always 20 years away haha" jab.

Look, it's really simple:

1. This is a very hard and expensive problem.

2. Progress IS being made.

It's not clever or cute to diminish progress on this problem.

devin 2022-12-13 00:20 UTC link

I am not a physicist. Most here aren’t but fancy themselves experts on things they know precious little about. I’m not surprised but I agree it’s disappointing.

teilo 2022-12-13 00:25 UTC link

Early reports are are not good. For every joule delivered to the chamber, it takes 100 joules of electrical power. Heat to electricity is 50% efficient at best. Reports are that with 2.1mj of input, they generated 2.5 mj of output. Taking inputs and electrical production into account, this means 0.6% is all they are getting out vs. what they put in.

These over-unity reports are meaningless, because every damn one of them only measures Q-plasma, not Q-total.

floxy 2022-12-13 00:35 UTC link

>Their most recent article has a ton of great data and next steps:

That device in the photo is great. Looks to be about 16AWG magnet wire. Guessing a 10mm ID of the coil, and about 25mm in length. To get to 26 Tesla, looks like you'd need to push about 33,000 A through that coil. Coil inductance might be about 1uH, and if the test lasts ~1us, then you'd need 33kV to push that 33kA through the coil. 30kV/inch insulation resistance, might not get arcing between the wires in air. Probably running the thing in vacuum? Looks like things check out.

https://www.eeweb.com/tools/magnetic-field-calculator/

>NIF has uncovered some new science

What is the new science? Seems like they are working on making the fuel pellets closer to perfect, which makes sense if you are trying to use the implosion shock wave inside the fuel to be the source of heat and pressure needed for further fusion. I'm imagining that the laser initiates the surface fusion, and then you want that fusion to propagate inward, and need thing perfect, so the fuel doesn't go squirting out the sides (so to speak) stopping the chain reaction.

SantalBlush 2022-12-13 00:54 UTC link

>Very disappointed by the discourse in this HN thread. The same old quips over and over.

We see these comments on every science thread because almost all of these people lack the requisite expertise to weigh in on the actual details, so instead they make a high-level criticism to give the appearance of having some kind of knowledge on the subject. Moreover, they think that crapping on things equates to being a critical thinker, and have convinced one another that this is so.

tuatoru 2022-12-13 01:00 UTC link

For certain values of engineering steps.

Scaling up Qplasma from 1 to ~1000, and scaling up operating time from a microsecond to a megasecond are just two of them.

I have a feeling there is still some science to do.

floxy 2022-12-13 01:08 UTC link

I'm a complete layman when it comes to ICF, but I'm assuming that there is a scaling factor between surface area and volume that would eventually help here? As in, the lasers initiate fusion on the surface of the fuel pellet, which propagates the fusion into the interior of the pellet in a chain reaction / positive feedback kind of way. So that if you increased the surface area of the pellet by a factor of 10, you'd get 100 times more total output energy (since there is 100 times more mass in a pellet with 10 times the surface area). So you'd need 10 times the current input power, but would get 100 times the output power.

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