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Major breakthrough on nuclear fusion energy

bbc.co.uk

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Re: Major breakthrough on nuclear fusion energy

#171

Post by ambrozk »

DrBazza wrote: post #87
dfdz wrote: post #80

> This is more than double what was achieved in similar tests back in 1997. The experiment produced > 11 megawatts of power and at Jet > two 500 megawatt flywheels are used to run the experiments log_2(2*500/11)*(2022-1997) + 2022 = 2185 At this rate we will have fusion by 2185 I guess?

It's 30 years time. It's always 30 years time. https://www.discovermagazine.com/technology/why-nuclear-fusi...

This is a very dumb meme that people use to avoid learning anything about the actual hurdles that are currently being faced by fusion researchers. At some point, fusion will be much less than 30 years away, and at that point, I guarantee you that lazy people will still be repeating this joke, because it is literaly the only thing they know about the subject.

Re: Major breakthrough on nuclear fusion energy

#172

Post by dymk »

ComradePhil wrote: post #161
formvoltron wrote: post #105

OK so with fusion everybody loves it because the fuel would be clean and nearly endless. Isn't that what solar power offers? Nobody wants to deploy solar due to high upfront cost. However, wouldn't the startup on a fusion reactor be much greater?

No. Fusion is completely different from solar. It can provide steady energy without going down for years. Solar goes down multiple times a day.

Name a single fusion plant that has been running uninterrupted for years.

Meanwhile Australia has retooled for 10% Solar and batteries in a matter of years, that number is rapidly increasing, and is turning off their coal plants.

Re: Major breakthrough on nuclear fusion energy

#173

Post by MobiusHorizons »

oakwhiz wrote: post #135
limaoscarjuliet wrote: post #109

According to Sabine Hossenfelder, published numbers are frequently mis-stated on purpose. When you look at frequently reported Q Plasma (or plasma efficiency) we are not that far from it being > 1. However, we should look at Q Total (total efficiency), which is still way below https://www.youtube.com/watch?v=LJ4W1g-6JiY For years, I was hoping fusion is close. After watching Sabine's video, I'm not so optimistic anym…

Why would any experimenters optimize for Q total if Q plasma is a prerequisite to get anywhere?

The concern is that experimenters are wasting time on experiments with promising looking Q plasma but with orders of magnitude smaller Q total (eg pulsed laser systems)

It’s important not to forget the big picture. Otherwise you end up optimizing one piece of the system, and causing another piece of the system to work less well in a way the degrees overall system performance.

Re: Major breakthrough on nuclear fusion energy

#174

Post by timthorn »

n4r9 wrote: post #117
andyjohnson0 wrote: post #108

Earlier quoted context omitted.

I think the point that your parent commenter was making is that Oxford is in the UK and the UK is no longer a member of the EU or Euratom, although it has various agreements with both.

I think OP was commenting more on the emphasis, i.e. one of the titles highlighting the name "Oxford" just because it's famous. The UK is still in Europe and will likely be for decades to come.

JET is based near Oxford, and in an article from the BBC provides useful geographic context for the UK audience. I don't think it is mentioned because Oxford is "famous".

Re: Major breakthrough on nuclear fusion energy

#175

Post by moogly »

ppaattrriicckk wrote: post #59

In extension to this news and the press conference, one thing I am super excited about, is the private SPARC project and the MIT-spinoff Commonwealth Fusion Systems (CFS). If you don't know about it already, I would highly recommend checking it out (e.g. by searching YouTube for "MIT Sparc Fusion Reactor" for some fairly accessible videos on the theory behind why they should achieve fusion way faster than the current…

> Theory dictates that with stronger magnets, the reactor can be scaled down (with the square/cube, can't remember exactly), and thus cost and time to develop

OTOH, in a tokamak, the plasma volume (and potential energy output) scales quadratically with the torus' aspect ratio (ratio of major to minus radius), so I'm not sure that tokamak-based fusion really is particularly suitable to miniaturization.

Re: Major breakthrough on nuclear fusion energy

#176

Post by SamBam »

lisper wrote: post #163
reacharavindh wrote: post #107

As an uneducated observer to nuclear physics, I could not tell the significance of this achievement. Did we finally learn how to extract more energy from a fusion rector than we supplied to operate it? Could anyone more in the know here explain in simpler and more practical terms please?

> Did we finally learn how to extract more energy from a fusion rector than we supplied to operate it? No. > Could anyone more in the know here explain in simpler and more practical terms please? It's impossible to tell because the story is incoherent. The central claim is that they "release[d] a record 59 megajoules of sustained fusion energy" but this makes no sense. One can talk about sustained power (over a perio…

I don't believe that this is entirely mis-stated.

We already know that fusion power plants are going to operate by igniting plasma in short bursts -- a few seconds, maybe 10s at most -- and generating a huge amount of power during that single burst. You then ignite it again and again.

The question is how much total energy you can extract from each of those bursts. By that metric, the total energy is what's important, not the power. Producing 10 quadrillion watts of power isn't that useful if it's only for 100 trillionths of a second. (Both numbers pulled from an actual recent result last August. [1])

"59 megajoules of sustained fusion energy" means a single burst produced that much. That's significantly more than the paltry 1.3MJ from that other result I just linked to.

Yes, of course you could get that much from a wall socket over the course of hours, but we know we haven't been able to sustain a fusion reaction for a few seconds, so that's the timeframe we're talking about for a single burst.

1. https://www.livescience.com/fusion-experiment-record-breakin...

EDIT: And, at the bottom of the article it says that the reaction ran at 11MW, so plugging that in it sounds like, indeed, it ran for 5 seconds.

Re: Major breakthrough on nuclear fusion energy

#179

Post by bumby »

dymk wrote: post #169
AniseAbyss wrote: post #157

Earlier quoted context omitted.

I'm not really sure about that. The promise of fusion power is so great that it would be idiotic not to throw money at it. The US was spending a billion a week in the Afghanistan war.

You just gave a great example of the irrationality of how things are funded. Idiotic things get cash thrown at them, National healthcare rests on the sidelines.

I think it matters on perspective. That funding might be considered rational if you were a congressperson who have a vested interest in certain lobbies. Not saying it's necessary moral or optimizing for the right thing for society as a whole, but it may be rational.

Re: Major breakthrough on nuclear fusion energy

#180

Post by travisgriggs »

dymk wrote: post #169
AniseAbyss wrote: post #157

Earlier quoted context omitted.

I'm not really sure about that. The promise of fusion power is so great that it would be idiotic not to throw money at it. The US was spending a billion a week in the Afghanistan war.

You just gave a great example of the irrationality of how things are funded. Idiotic things get cash thrown at them, National healthcare rests on the sidelines.

Just wait… it’s kind of a tired trope, but I still think there will yet be a “War on Climate Change.”

/s

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