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Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

imperial.ac.uk

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Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#41

Post by ruste »

xxpor wrote: post #35
AutumnCurtain wrote: post #21

Earlier quoted context omitted.

>Early reports estimated that 250 kilo-joules of energy was deposited on the target (roughly 2/3 of the energy from the beams), which resulted in a 1.3 Megajoule output from the fusing plasma. Incredible progress over where they were just a couple years ago.

For reference: 1 MJ = 0.277778 kWh. Not trying to knock the progress made or anything like that, I just needed the conversion to a more familiar unit in order to appreciate what sort of scale they're talking about.

When thinking of this amount of energy in kWh it seems small, but if this is deposited by lasers in a small fraction of a second it seems like a huge amount of power delivery.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#42

Post by ckuehne »

mlindner wrote: post #25
akeck wrote: post #6

Earlier quoted context omitted.

Probably just "plasma breakeven" Sabine talks about the issue. [1] https://backreaction.blogspot.com/2021/10/how-close-is-nucle...

Sabine actually is completely misleading and misconstrues a bunch of facts. None of these plants are even attempting to have real energy breakeven and spend a ton of energy supplying experiments and unrelated support equipment. They don't even have a method of capturing energy as that's not the point as it would make it harder to test the physics. Additionally these plants have high amounts of "startup energy consump…

I think your statement "Once you have plasma breakeven you have a self-sustaining heater basically" is false. According to Wikipedia [1] - if I interpret it correctly - the fusion energy gain factor from plasma must be 5 (!) to have a self-sustaining heater:

"Most fusion reactions release at least some of their energy in a form that cannot be captured within the plasma, so a system at Q = 1 will cool without external heating. With typical fuels, self-heating in fusion reactors is not expected to match the external sources until at least Q = 5"

[1] https://en.wikipedia.org/wiki/Fusion_energy_gain_factor

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#43

Post by xxpor »

ruste wrote: post #41
xxpor wrote: post #35

Earlier quoted context omitted.

For reference: 1 MJ = 0.277778 kWh. Not trying to knock the progress made or anything like that, I just needed the conversion to a more familiar unit in order to appreciate what sort of scale they're talking about.

When thinking of this amount of energy in kWh it seems small, but if this is deposited by lasers in a small fraction of a second it seems like a huge amount of power delivery.

Yeah, the time scale and volume of where it's happening matters a lot.

It's like in fission when you read about reactions giving net energy of X MeV. If you convert that to even Wh, let alone kWh, it's an incredibly small number. But when you start multiplying by the number of atoms in a fuel source, it starts adding up VERY quickly.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#44

Post by iammisc »

Iv wrote: post #32
greenail wrote: post #14

Sweet, nucluear fusion now must only be 20 years away!

20 years ago we were joking about it being 40 year away. So yes, it is timely progress. I am still bitter that we don't invest more on this research which has the potential to solve the climate crisis "unexpectedly".

> I am still bitter that we don't invest more on this research which has the potential to solve the climate crisis "unexpectedly".

Unfortunately, solving the climate crisis would put many a pundit out of a job.

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#48

Post by capekwasright »

hangonhn wrote: post #39
gene-h wrote: post #20

Earlier quoted context omitted.

What's important here is that they may have achieved ignition, that is making the fusion reaction self sustaining[0]. Once it becomes self sustaining one should be able to add more fuel to the pellet to get more energy out for the same input energy. It's worth noting that NIF was not intended to generate power and is not representative of a potential power plant. The lasers on NIF are old and were chosen to have a lo…

What is the goal of NIF? I've read repeatedly that fusion power isn't their end goal but rather to study inertial confinement. That's fine but why study inertial confinement if not to generate power? I've always been very confused about their goal. I'm a total layman when it comes to this stuff so there's some nuance I'm not understanding. Appreciate any clarification anyone can give.

In terms of the NIF's broader goal, as opposed to the specific goals for their ICF work, the NIF is meant to keep nuclear physicists fresh on research relevant to nuclear weapons design in the aftermath of the end of the Cold War and Comprehensive Nuclear Test Ban Treaty. [1]

[1] https://en.wikipedia.org/wiki/National_Ignition_Facility#NIF...

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#49

Post by aerostable_slug »

hangonhn wrote: post #39
gene-h wrote: post #20

Earlier quoted context omitted.

What's important here is that they may have achieved ignition, that is making the fusion reaction self sustaining[0]. Once it becomes self sustaining one should be able to add more fuel to the pellet to get more energy out for the same input energy. It's worth noting that NIF was not intended to generate power and is not representative of a potential power plant. The lasers on NIF are old and were chosen to have a lo…

What is the goal of NIF? I've read repeatedly that fusion power isn't their end goal but rather to study inertial confinement. That's fine but why study inertial confinement if not to generate power? I've always been very confused about their goal. I'm a total layman when it comes to this stuff so there's some nuance I'm not understanding. Appreciate any clarification anyone can give.

> What is the goal of NIF?

Nuclear weapons, more specifically stockpile stewardship (what happens as weapons age) and verification of weapons codes/simulation software (can we make new weapons without full-scale testing).

Everything else is gravy. There's a reason it's at one of the weapons labs (vs. the unclassified work done at most other national laboratories).

Re: Major nuclear fusion milestone reached as ‘ignition’ triggered in a lab

#50

Post by aerostable_slug »

option wrote: post #10

fusion sound fantastic in principle. But in the meantime we can and should addressed most of our energy needs with fission.

Not sure why this is downvoted. Fission works, and it works well. The waste problem is massively overstated and also, aside from NIMBY politics, solved.
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