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US Department of Energy: Fusion Ignition Achieved

energy.gov

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Re: US Department of Energy: Fusion Ignition Achieved

#441

Post by azinman2 »

pfdietz wrote: post #380
azinman2 wrote: post #238

Earlier quoted context omitted.

To achieve fusion for power production, you need more output than input. For 60+ years this hasn’t been achieved in a replicated fashion. Now it has, and it’s 50% more power rather than 0.1% more power as was sometimes shown for 2 nanoseconds before. So now we know fusion for power is possible. If it can be scaled successfully (now likely not an if anymore, but a function of time), then we have the ability to have cl…

I'm asking why this somewhat arbitrary line being crossed is something I should care about. It doesn't imply fusion will reach a state of practical application. Why is this more exciting that achieving a ratio of .1, or .5, or 2, or 10? It seems entirely arbirary to me, and smells of an argument that somehow this has made the end goal significantly more attainable.

Because until now contained ignition has never produced anything meaningful. We've had failed experiment after failed experiment. Now we finally have an experiment with a meaningful more amount of energy out than in.

Is this the right approach? Who knows. There are many fusion designs in the works, and those may ultimately be the right call. Or some yet-to-be-created design. That's even probable. The NIF is for simulating nuclear weapons, not creating energy. None of that takes away from this breakthrough - we've never had meaningfully more output than input on a repeatable basis. It's proof that contained fusion for energy isn't just hypothetical, which will also mean funding & interest will generally increase from this point on.

I think you're setting too high a bar. It's like saying no milestone should be celebrated until we have a working metropolitan-size plant running that's cheaper than anything else. Punch cards in the 1950s are insignificant compared to modern SSDs, yet they were an important step even though we don't use anything like it now. Breakthroughs are breakthroughs.

Re: US Department of Energy: Fusion Ignition Achieved

#442

Post by ceejayoz »

exmadscientist wrote: post #307
jerf wrote: post #139

Earlier quoted context omitted.

Fusion bombs have existed since the early 1950s. Technology rapidly developed to the point that they can essentially be built to be arbitrarily large, far beyond any practical war purpose. There is no need for any larger bomb than what was built many decades ago. None of this research is necessary for bombs. All of the difficult problems fusion power generation faces with long-term plasma confinement go away when you…

> None of this research is necessary for bombs. And yet that's exactly why the NIF was actually built. They do plenty of weapons research: https://wci.llnl.gov/facilities/nif I'm told the building was even built to switch over between civilian and classified use unusually quickly, but I'm having trouble turning up a citation for that right now with just my phone and 2022-Google. > All of the difficult problems fusion…

> And yet that's exactly why the NIF was actually built.

You're both half-right.

The NIF is the replacement for nuclear tests. It's necessary to maintain the arsenal in a working fashion, as the warheads degrade over time and have to be replaced with new ones. https://www.npr.org/templates/story/story.php?storyId=655921...

The NIF is not for more powerful nuclear weapons, as that's entirely unnecessary. If anything, most interest these days is in less powerful weapons for potential battlefield use.

Re: US Department of Energy: Fusion Ignition Achieved

#443

Post by jmartrican »

eklitzke wrote: post #262
spullara wrote: post #165

Earlier quoted context omitted.

If you look at the mass before of their fuel, 1 deuterium atom + 1 tritium atom: 2.01410177811 u + 3.01604928 u = 5.03015105811 u vs the mass of the fusion products of 1 helium atom and 1 neutron: 4.002602 u + 1.008 u = 5.010602 u You'll notice that even though we started with 5 neutrons and 2 protons and ended up with the same number there was some additional binding energy that is unaccounted for in the new configu…

Tangentially related, but I think this is an interesting fact, all the atoms in our universe/galaxy/solar system with a mass up to that of iron are formed in the core of stars in stellar fusion. Hydrogen fuses into helium, and as a star nears the end of its lifetime you get heavier elements like lithium, carbon, and so on. Under normal stellar fusion no elements heavier than iron will be produced, and iron is only el…

So that means that for life to form, we probably need a star to die so that the heavier atoms used in complicated life forming chemical reactions (correct me if i am wrong here as what I'm about to say depends on it), hence it could be the case that if the universe is 13.5 billion years old, then we humans are appearing in the universe at the earliest possible time.

13.5 billion years seems like the time required to create a star, have the star die and blow up, have all that material settle and create a new star, then the planets are formed, than enough time on one of those planets needs to pass for life to form, then complicated life.

Re: US Department of Energy: Fusion Ignition Achieved

#444

Post by fullshark »

rowanG077 wrote: post #231
azinman2 wrote: post #204

Earlier quoted context omitted.

Is the bottleneck for fusion money though?

money is always the bottleneck in some sense. There are diminishing returns but in general more money will make it happen faster.

The laws of physics also a limiting factor

Re: US Department of Energy: Fusion Ignition Achieved

#445

Post by yonaguska »

subsubzero wrote: post #372
spullara wrote: post #165

Earlier quoted context omitted.

If you look at the mass before of their fuel, 1 deuterium atom + 1 tritium atom: 2.01410177811 u + 3.01604928 u = 5.03015105811 u vs the mass of the fusion products of 1 helium atom and 1 neutron: 4.002602 u + 1.008 u = 5.010602 u You'll notice that even though we started with 5 neutrons and 2 protons and ended up with the same number there was some additional binding energy that is unaccounted for in the new configu…

Do we know how much tritium is needed for a city's energy generation? What about a state etc? Reason I ask is the only uses I have seen for tritium is on old watch dials made in the pre-90's. Curious how much of this resource is out there.

Tritium is very popular on gun sights as well- as it's a glow in the dark sight that doesn't need to be charged. I'm now questioning the practice of appendix carrying with tritium sights.

Re: US Department of Energy: Fusion Ignition Achieved

#446

Post by OJFord »

whimsicalism wrote: post #395
petilon wrote: post #349

Earlier quoted context omitted.

When you consider that they laser they used consumed 300 megajoules from the wall plug, in order to send 1.8 megajoules to the target, the fact that they got 2.5 megajoules out looks puny in comparison. Even newer lasers only have 20% wall plug efficiency according to the press conference. So the important point here is, there was no net energy gain. They spent 300 megajoules to get 2.5 out. The scientists only talk…

Energy is conserved in the universe so there is never any net energy gain. See how pedantic and not helpful that is?

The point is to get some of it from somewhere cheaper/free - mass, or outside air as in heat pumps.

You can't run your laser on mass or air, if you need a coal firing power plant to run your fusion reactor, from which you get less than you consumed from the coal plant...

It's great progress, it's just not as close to viable as it might sound like - more breakthroughs needed.

Re: US Department of Energy: Fusion Ignition Achieved

#447

Post by lostmsu »

pdonis wrote: post #98

Calling this "ignition" is a misnomer. The correct term, as given in the article (as opposed to the headline) is exceeding breakeven: more fusion energy output than energy input to the target. "Ignition" means the reaction becomes self-sustaining and does not require any further input of energy to continue.

> the reaction becomes self-sustaining

This is applicable only to continuously running reactions like in jet engines.

Re: US Department of Energy: Fusion Ignition Achieved

#448

Post by lr1970 »

nkrisc wrote: post #325
bmmayer1 wrote: post #103

Earlier quoted context omitted.

This is a stupid question but I don't know anything about fusion: How is it possible for X energy to create X+Y energy in output? Doesn't that violate some fundamental law of physics?

Mass and energy are equivalent. You're using X energy to reduce the mass of your fuel and converting that mass into Y energy. When X The reason nuclear fusion is such a desirable goal is because it only takes a relatively small amount of mass to convert into a relatively large amount of useful energy, and the mass (the fuel) is relatively easy to obtain. Like all energy generation, it's converting one type of energy…

> Mass and energy are equivalent.

Mass is energy at rest, hence equivalence with exception of massless particles like photons that have zero mass and non-zero energy. Also, photons travel with the speed of light in vacuum and cannot be found at rest in any frame of reference. Modern physics is fun, isn't it?

P.S. Neutrinos were thought to have zero mass as well, but according to the Standard model they have mass.

Re: US Department of Energy: Fusion Ignition Achieved

#449

Post by willis936 »

mustacheemperor wrote: post #2

I don't know about everyone else, but I'm taking this particular moment just to swell with pride and excitement for this achievement by science and forget about the details of how much more needs to be done to create the first power plant. I'm remembering when I first learned about fusion energy development, how distant and unfeasible it seemed, and regardless of how long the road ahead still is it's incredible how f…

I listened to the two hour press conference. NIF leadership made it clear that energy research is not what Ignition Day is about, why the NIF was made, or why the NIF is operated.

Re: US Department of Energy: Fusion Ignition Achieved

#450

Post by boc »

sillysaurusx wrote: post #379
ganbatekudasai wrote: post #331

Earlier quoted context omitted.

Don't take it too personally, but you, and many others here, need to rethink their approach. You see a short tweet without context about a topic you clearly know nothing about (which is totally, fully okay, it's a complex topic), and think you are now able to criticize milestones in this impossibly complex topic. Not even ask questions, not something like "hey, I saw this tweet, I know it's just a tweet, but can some…

No thanks. I get that people are emotional about this, but it’s important to treat science with a critical eye. The claim is that more energy came out than was put in. This is false. It’s not just me saying it. https://www.tiktok.com/t/ZTRVP5Pmg/ There is no “context” to understand. Yes, it’s an impressive feat. Yes, other laser designs might fix the huge ignition costs. But that hasn’t happened yet , and until it do…

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