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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

#321

Post by dsfyu404ed »

jameshart wrote: post #294
dsfyu404ed wrote: post #131

Earlier quoted context omitted.

You know how when you burn something you release the energy in the chemical bonds? Fusion and fission are like that but for atoms instead of molecules.

Except… chemical bonds don’t ‘store’ energy. Molecules are a low energy configuration . It takes energy to rip them apart! But, O2 molecules, with their double bond, don’t take much energy to break apart. If they do, and then pair up with say a bunch of Hydrogen and Carbon atoms that were nearby in some long chain or something, they form bonds that are stronger - that take more energy to break - and you end up with s…

There's a fundamental tradeoff between technical precision and explaining things in a way that's relatable to simpler stuff. Deal. With. It.

Re: US Department of Energy: Fusion Ignition Achieved

#322

Post by orthecreedence »

Firmwarrior wrote: post #289
orthecreedence wrote: post #272

Earlier quoted context omitted.

I'm confused by this. Does the US have the productive forces and resources to replace petrolium with solar panels (and the required energy storage)? Does it have the nuclear fuel to replace petrolium with fission reactors? What alternatives to petrolium does the US have that it does not rely on others for?

Nuclear fuel actually isn't that expensive or rare Those crazy sci-fi stories from the 30s and 50s where everyone used nuclear power (and it was so cheap they didn't bother to meter it) were all completely accurate from a non-political viewpoint

Oh, interesting. I read/heard a few places that most fuel used for fission was controlled by a few countries. I was unaware it was abundant.

Re: US Department of Energy: Fusion Ignition Achieved

#323

Post by devmor »

dharmab wrote: post #126
thehappypm wrote: post #45

Earlier quoted context omitted.

It’s potentially just a much better version of fission. Fusion won’t cause a runaway reaction — in fact it’s brutally difficult to get it to react at all, hence why this is an achievement. It also doesn’t use materials that can be used for a bomb, again unlike fission. As a result it has the potential to be cheaper to implement, cheaper to fuel, with no meltdown risk.

Isn't tritium used in fusion and a potential weapons material?

It's a fission yield booster. It's as much of a weapons material as charcoal is.

Re: US Department of Energy: Fusion Ignition Achieved

#324

Post by xattt »

maria2 wrote: post #305
rowanG077 wrote: post #231

Earlier quoted context omitted.

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

This is like saying thread count is always the bottle neck in computation. More money allows more parallelism as you can pay for more people and more equipment for more research. As in computing, there are diminishing marginal returns and surely a version of Amdahl's Law for human endeavors.

> thread count is always the bottle neck in computation

The softer the bed linen, the more rested the computer scientists will be and the more likely they are to come up with novel solutions that lead to faster computing.

Re: US Department of Energy: Fusion Ignition Achieved

#325

Post by nkrisc »

bmmayer1 wrote: post #103
jkelleyrtp wrote: post #33

> LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE) Yesterday, everyone was complaining about the 2.2:2.0 ratio, but now we're working with 3.15:2.05. With modern lasers, that'd be a total Q of 0.375 assuming 100% ef…

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 into another, more convenient type, to do useful work. Like a hydroelectric dam converting the potential energy of water into more useful electrical energy. Energy is conserved when water spins a turbine, it's just that electrical energy is more useful for work than the potential energy of the water. Of course you can still use the potential (or kinetic) energy of the water directly, such as with a water mill. But the energy to work ratio is worse in that form (especially if the work to be done is far away from the watermill).

Whenever you build a fire you need to input some amount of energy to begin the chemical reaction that releases energy. In this instance we get not electrical energy, but energy in the form of infrared and visible light, to heat our home and light our way. Yet the total energy released by the fire far surpasses the energy you used to start the reaction, but because the wood's mass is consumed, energy is ultimately conserved. You have converted wood (not useful for heating your home) into infrared light (useful for heating your home).

Re: US Department of Energy: Fusion Ignition Achieved

#326

Post by tootie »

bioemerl wrote: post #20

Here's your most exciting paragraph > LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE). Many advanced science and technology developments are still needed to achieve simple, affordable IFE to power homes and busines…

There are already funded commercial fusion projects underway. No idea which will bring a product to market first or at all, but they suddenly seem a lot more plausible.

https://www.nytimes.com/2021/08/10/technology/commonwealth-f...

Re: US Department of Energy: Fusion Ignition Achieved

#327

Post by Quarrel »

pfdietz wrote: post #171
echelon wrote: post #105

Earlier quoted context omitted.

It will get there. It's just a matter of time and resources. The destination will be a milestone for humanity, so we should not give up.

Why should I agree with this article of faith? The obstacles appear quite grave to me. Moreover, even reaching that Q doesn't mean we're there. That's a necessary, not sufficient, condition. A large, complex machine that explodes the equivalent of 500 lb. bombs to generate heat to drive a turbine sounds like an engineering nightmare.

While I'm sure that you're correct, the obstacles are large and there is a lot of overcome still, I can't help but think of James Watt & (my ancestor) Richard Trevithick - the inventor/pioneer of the compact steam engine.

Watt went around telling everyone that Trevithick and his compact (ie high pressure) steam engines were too dangerous and would never work.

Yes, some exploded. But then we got steam trains and even today almost all power generation on the planet is high pressure steam-electric power plants.

Re: US Department of Energy: Fusion Ignition Achieved

#328

Post by 867-5309 »

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…

we are all made of star stuff

Re: US Department of Energy: Fusion Ignition Achieved

#329

Post by qorrect »

aaroninsf wrote: post #228
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…

This is an A+ comment—helpful, well-formatted, concise, with bonus interesting additional detail. Thank you.

Yes well done .

Re: US Department of Energy: Fusion Ignition Achieved

#330

Post by petilon »

Rebelgecko wrote: post #144
sillysaurusx wrote: post #115

Earlier quoted context omitted.

This tweet claims that 500MJ of energy was required: https://twitter.com/latzenpratz/status/1602686252486217728 > "had to put 500 megajoules of energy into the lasers to then send 1.8 megajoules to the target - so even though they got 2.5 megajoules out, that's still far less than the energy they originally needed for the lasers," says Tony Roulstone of the University of Cambridge. But it's good to finally see progre…

It was discussed a lot in the threads about this yesterday, but apparently the lab had relatively inefficient lasers. Newer ones are an order of magnitude more efficient

This is what I captured from the press conference:

300 megajoules was used to generate the laser (this is also captured in [1]). They also mentioned that newer lasers have 20% wall plug efficiency. If so, they need to improve the energy output by 5x in order to break even relative to wall plug energy consumption.

[1] https://techcrunch.com/2022/12/13/world-record-fusion-experi...

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