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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

#881

Post by vincnetas »

opportune wrote: post #584
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…

100% agree. We should be dumping as much as we can in getting fusion up and running ASAP. It could be a silver bullet to stop climate change alone, and by driving energy costs lower, enable huge innovations in AI/automation and increasing material wealth. $1T to move fusion forward just 5 years from eg 2040 to 2035 could alone have a huge ROI in terms of climate mitigation and decarbonization

With abundant electricity wouldn't we face another type of global warming? We will would start to consume so much electricity that this will heat up the planet?

Re: US Department of Energy: Fusion Ignition Achieved

#882

Post by defrost »

vincnetas wrote: post #881
opportune wrote: post #584

Earlier quoted context omitted.

100% agree. We should be dumping as much as we can in getting fusion up and running ASAP. It could be a silver bullet to stop climate change alone, and by driving energy costs lower, enable huge innovations in AI/automation and increasing material wealth. $1T to move fusion forward just 5 years from eg 2040 to 2035 could alone have a huge ROI in terms of climate mitigation and decarbonization

With abundant electricity wouldn't we face another type of global warming? We will would start to consume so much electricity that this will heat up the planet?

Relative scales of various factors matter here:

We aren't "heating up the planet" .. we're "insulating the atmosphere".

Increased C02 (and the close following methane and water vapor increases) serve to trap more of the heat radiated outwards that would otherwise escape.

The vast bulk of that heat comes from the visible light of the sun which passes easily through the atmosphere coming in, gets converted to IR energy as it warms the earth and oceans, and then escapes outwards.

Our changes to the atmosphere have disturbed that balance.

Your comment has some small merit, but you would need to work through the heat output of human generated power and then compare that to the daily heat energy originally from the sun that radiates outward.

Re: US Department of Energy: Fusion Ignition Achieved

#883

Post by atemerev »

_cs2017_ wrote: post #771
jboy55 wrote: post #696

Earlier quoted context omitted.

and not a gigantic amount of fusion that you have in thermonuclear weapons, 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 n…

How would it help build better weapons? I thought the existing thermonuclear bombs do the job perfectly fine. Sure, the military might want to make them a bit smaller or a bit cheaper, but is it really such a big deal as to warrant a major announcement?

To learn about their degradation modes and how to maintain them (since full-scale nuclear tests are now verboten, and subcritical experiments only deal with fission part of the entire assembly -- we now also need some experimental setup to test the fusion part: radiation pressure, X-ray reflection, ablation modes etc. NIF is this setup).

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.

Re: US Department of Energy: Fusion Ignition Achieved

#884

Post by scoopertrooper »

kubanczyk wrote: post #879
pauljurczak wrote: post #820

Earlier quoted context omitted.

> USA probably won't have an effective arsenal within a century. If other countries joined, it would be a great outcome.

> > USA probably won't have an effective arsenal within a century. > 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…

I don’t think MAD is all that effective. At this moment in time we’re seeing:

* 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.

Re: US Department of Energy: Fusion Ignition Achieved

#885

Post by cloudhead »

eru wrote: post #793
floxy wrote: post #686

Earlier quoted context omitted.

I guess we should take this as a lesson in communications. The "breakeven" thing is a red-herring that should have been have been left out of the message, or at least only mentioned as a footnote. The critical ELI5 message that should have been presented is that they used a laser to create some tiny amount of fusion. But we have been able to do that for a while now. The important thing is that they were then able to…

> [...], or the ginormous fusion of the sun. 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.

How is the sun so hot then?

Re: US Department of Energy: Fusion Ignition Achieved

#886

Post by [deleted] »

eru wrote: post #832
aoetalks wrote: post #810

Earlier quoted context omitted.

This is incredible.

To give some more detail: hydrogen to helium fusion (even with intermediate steps) is extremely unlikely to happen. That's part of why the sun will last for billions of years. And that's also why first human attempts at fusion are not trying to use straight up hydrogen as the fuel. 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…

[deleted]

Re: US Department of Energy: Fusion Ignition Achieved

#887

Post by martopix »

cloudhead wrote: post #885
eru wrote: post #793

Earlier quoted context omitted.

> [...], or the ginormous fusion of the sun. 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.

How is the sun so hot then?

Presumably it's so big that this amount adds up, and it's sufficiently isolated to heat up without losing too much power towards the outside

Re: US Department of Energy: Fusion Ignition Achieved

#888

Post by jacquesm »

_cs2017_ wrote: post #835
jacquesm wrote: post #774

Earlier quoted context omitted.

Given the limitations on nuclear research for weapons purposes any information that can be gleaned from these experiments that is 'dual use' is more than welcome with the parties that are currently stymied by various arms control agreements. This is also why you will see a lot of supercomputer capacity near such research, it allows simulation of experiments with high fidelity rather than the experiments themselves. T…

Presumably these computer models are mostly useful for creating new designs (since the old designs were proven by real tests). Would such new designs be convincing enough to the adversary to fulfill its role as a strategic deterrence? 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 h…

> the Russians may start wondering if the US aresnal actually works, no?

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.

Re: US Department of Energy: Fusion Ignition Achieved

#889

Post by diordiderot »

poopbutt7 wrote: post #812
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…

You are correct: this is the important point. Until this is actually powering homes at scale and competitive price- which, clearly from these numbers is a fantasy- developments in this field should be dismissed. It's embarrassing to see HN so excited about what's really quite the failure. (Sent from my ENIAC)

> ENIAC was the first programmable, electronic, general-purpose digital computer, completed in 1945.

Re: US Department of Energy: Fusion Ignition Achieved

#890

Post by martopix »

whycome wrote: post #690
SiVal wrote: post #612

Earlier quoted context omitted.

Iron is always spoken of as the dividing line, but I'd like to know whether iron is exactly on the line, on one side (which?), or it depends. IOW, does fusion of iron atoms release energy (hydrogen side of the line), absorb energy (uranium side of the line), neither, or either (depending on conditions)?

The periodic table is pretty awesome. But I wonder if there's a layout that takes into account this fission/fusion division? Would it just be a line? -- Yeah there are a few alternative designs, but nothing that seems to do the division. https://en.wikipedia.org/wiki/Alternative_periodic_tables

That's because the periodic table is essentially about chemistry (i.e. about electron orbitals), not about nuclear physics (i.e. the atom's nucleus). For example it doesn't talk much about isotopes, aside from usually reporting the average atomic mass.
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