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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

#21

Post by AutumnCurtain »

xixixao wrote: post #16

> Fusion ignition is the point at which a nuclear fusion reaction becomes self-sustaining. This occurs when the energy being given off by the fusion reactions heats the fuel mass more rapidly than various loss mechanisms cool it. https://en.m.wikipedia.org/wiki/Fusion_ignition

>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.

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

#22

Post by dogma1138 »

gene-h wrote: post #20
tantony wrote: post #2

Is this "plasma breakeven" or overall break-even?

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…

Don’t you still need to spend energy on confinement? You don’t need to “reignite” the plasma but w/e confinement solution you chosen still has a cost and a non marginal one when it comes to magnetic confinement.

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

#23

Post by gremIin »

xixixao wrote: post #16

> Fusion ignition is the point at which a nuclear fusion reaction becomes self-sustaining. This occurs when the energy being given off by the fusion reactions heats the fuel mass more rapidly than various loss mechanisms cool it. https://en.m.wikipedia.org/wiki/Fusion_ignition

How is this any different than the term 'breakeven' [0]?

> Breakeven describes the moment when plasmas in a fusion device release at least as much energy as is required to heat them

[0] https://www.iter.org/sci/BeyondITER

Is this just a case of multiple terms for the same phenomenon, and do plasma physicists have a preference?

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

#24

Post by detaro »

gremIin wrote: post #23
xixixao wrote: post #16

> Fusion ignition is the point at which a nuclear fusion reaction becomes self-sustaining. This occurs when the energy being given off by the fusion reactions heats the fuel mass more rapidly than various loss mechanisms cool it. https://en.m.wikipedia.org/wiki/Fusion_ignition

How is this any different than the term 'breakeven' [0]? > Breakeven describes the moment when plasmas in a fusion device release at least as much energy as is required to heat them [0] https://www.iter.org/sci/BeyondITER Is this just a case of multiple terms for the same phenomenon, and do plasma physicists have a preference?

The wikipedia article linked answers that.

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

#25

Post by mlindner »

akeck wrote: post #6
tantony wrote: post #2

Is this "plasma breakeven" or overall break-even?

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 consumption" that is also factored in to the energy usage but would be amortized out over a long run. Trying to use the absolute power consumption of the experiment as if that's where the state of the art is at for true energy break even is completely wrong.

Plasma breakeven is all anyone is really working on. Once you have plasma breakeven you have a self-sustaining heater basically, which then can be used to create energy. The point of an "ignited plasma" is that it's self-sustaining and just pumps out heat, even if most of the energy is used to keep the reaction going.

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

#26

Post by seoaeu »

vfclists wrote: post #19

Funny how this story gets posted after soon after Dr Sabine Hossenfelder's debunking and deflate the fusion power hype - https://www.youtube.com/watch?v=LJ4W1g-6JiY with a genuine Hans Gruber accent :)

Do you have any context on who Dr. Hossenfelder is or why their "debunking" is meaningful?

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

#28

Post by [deleted] »

gremIin wrote: post #23
xixixao wrote: post #16

> Fusion ignition is the point at which a nuclear fusion reaction becomes self-sustaining. This occurs when the energy being given off by the fusion reactions heats the fuel mass more rapidly than various loss mechanisms cool it. https://en.m.wikipedia.org/wiki/Fusion_ignition

How is this any different than the term 'breakeven' [0]? > Breakeven describes the moment when plasmas in a fusion device release at least as much energy as is required to heat them [0] https://www.iter.org/sci/BeyondITER Is this just a case of multiple terms for the same phenomenon, and do plasma physicists have a preference?

[deleted]

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

#29

Post by falcrist »

gremIin wrote: post #23
xixixao wrote: post #16

> Fusion ignition is the point at which a nuclear fusion reaction becomes self-sustaining. This occurs when the energy being given off by the fusion reactions heats the fuel mass more rapidly than various loss mechanisms cool it. https://en.m.wikipedia.org/wiki/Fusion_ignition

How is this any different than the term 'breakeven' [0]? > Breakeven describes the moment when plasmas in a fusion device release at least as much energy as is required to heat them [0] https://www.iter.org/sci/BeyondITER Is this just a case of multiple terms for the same phenomenon, and do plasma physicists have a preference?

That question is answered in the wikipedia link above.

> Ignition should not be confused with breakeven, a similar concept that compares the total energy being given off to the energy being used to heat the fuel. The key difference is that breakeven ignores losses to the surroundings, which do not contribute to heating the fuel, and thus are not able to make the reaction self-sustaining. Breakeven is an important goal in the fusion energy field, but ignition is required for a practical energy producing design.

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

#30

Post by mlindner »

lisper wrote: post #13
tantony wrote: post #2

Is this "plasma breakeven" or overall break-even?

Neither. From TFA: "While the latest experiment still required more energy in than it got out, it is the first suspected to reach the crucial stage of ‘ignition’, which allowed considerably more energy to be produced than ever before, and paves the way for ‘break even’, where the energy in is matched by the energy out." Here [1] is an excellent video by Sabine Hossenfelder about why you should not get too excited abo…

It's neither, agreed.

However, Sabine misconstrues things in the opposite direction and lies through omission to the audience. For example including startup energy and not ammortizing it over runtime, or not assuming that the energy consumption of the experiments is part of the required energy consumption of the fusion reactor, or trying to construe that once you have a fusion power reaction that is burning it is still especially difficult to further create a functioning power reactor out of it.

The true hard part of fusion is the burning plasma aspect. Once you have a burning plasma, it's a heat source like any other (with a few side-effects like neutron output) and everything we know from fission power reactors (but with a much lower radiation) and fossil fuel generators applies.

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