Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Major breakthrough on nuclear fusion energy

bbc.co.uk

Post reply on HN
Print view View original

781–790 of 827 posts

Re: Major breakthrough on nuclear fusion energy

#781

Post by kwhitefoot »

derriz wrote: post #140
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'm not sure it's Brexit related - but I've noticed more and more that when the UK media uses the expressions Europe or European, they are referring to the European continent as if the UK was not part of it. I've even heard it used in this capacity in a work presentation which caused confusion in the multi-national audience - "in Asia it's X, in Europe it's Y, in the UK it's Z...". I consume quite a bit of UK media s…

"Fog in channel, Continent cut off!"

Re: Major breakthrough on nuclear fusion energy

#782

Post by ajuc »

jcelerier wrote: post #775
ajuc wrote: post #156

Earlier quoted context omitted.

Fun fact - solar energy production over a year only differs by a factor of 4 between worst and best reasonably inhabited places.

> only differs by a factor of 4 how is a factor of 4 "only". It's absurdly high.

Is it? Oil/coal/gas reserves differ by factors of millions.

You only get 3 times less power/area of solar in Scotland than in California. That's pretty surprising (part of it is higher efficiency of photovoltaic cells in lower temperatures) and pretty great for our future.

For example it means once we switch from fossil fuels pumped out of the ground to fossil fuels generated with surplus renewable energy (and it's not that far - it will probably be profitable in most of the world in next decade) - there will be much less incentives for fossil fuel dictatorships.

Re: Major breakthrough on nuclear fusion energy

#783

Post by dicroce »

For me, a working net positive fusion reactor means a ton. Here are some things you could do with free (or essentially free) clean energy:

1) desalinization to provide water to everyone. 2) massive carbon capture 3) convert the world away from liquid fuels - and for the cases we are unable to do that, make the fuels from captured atmospheric carbon.

Re: Major breakthrough on nuclear fusion energy

#784

Post by tremon »

maccam94 wrote: post #640
elihu wrote: post #560

Earlier quoted context omitted.

ReBCO tape is the specific high-temperature superconducting material they're using. Another important material is FLiBe, which is a liquid that I think absorbs the energy from the fusion reactor. I don't really understand the properties that make it particularly well suited to the task, but I gather it's important. https://en.wikipedia.org/wiki/Rare-earth_barium_copper_oxide https://en.wikipedia.org/wiki/FLiBe

It captures neutrons and breeds tritium, which will be separated out and used to fuel the fusion reaction. https://www.sciencedirect.com/topics/engineering/breeding-bl...

The relevant breeder equations, since I was wondering how to create tritium by neutron capture without deuterium:

n + ⁷Li → T + ⁴He + n′

n′ + ⁶Li → T + ⁴He

(and ⁴He + n → D + T)

It didn't help that I was scanning the equations for ²H and ³H, not D or T.

Re: Major breakthrough on nuclear fusion energy

#785

Post by bin_bash »

rurp wrote: post #668
Xixi wrote: post #656

Earlier quoted context omitted.

It took more than 300 years to build the cathedral [1] in my home town (albeit with a 60-year pause in the middle). So indeed it might take another 4 or 5 generations to master nuclear fusion, but I see no issue with that. We should not shy away from starting projects that we won't see any benefit in our lifetime. But of course, it also means that we should not rely on nuclear fusion being available in the short term…

I suspect there was a lot of inceramental value to be had while the construction was ongoing. A cathedral doesn't need to be 100% complete to use as a house of worship, an inspiration for the community, a display of wealth and soft power, and so on. Fusion hasn't really produced much utility at all so far, aside from some interesting discussions.

Are you trying to argue therefore we should stop or something? There are countless areas of research and activities we do as humans that offer virtually no tangible benefit to society.

It seems to me that fusion is unfairly criticized because there is an obvious end-goal.

Re: Major breakthrough on nuclear fusion energy

#786

Post by mrpopo »

avidphantasm wrote: post #682
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…

At this point, I think fusion has the best chance of saving us from ourselves wrt to climate change, so long as the unforeseen consequences aren’t too bad.

Fusion would "solve" the climate change issue, but do nothing in regard to all other crises affecting our environment right now (biodiversity collapse, various sources of chemical and particulate pollution, fertilizer runoff...).

On the contrary, unlimited energy would exacerbate the man-made crises we are having today by further pushing the potential impact of man on its environment.

Re: Major breakthrough on nuclear fusion energy

#787

Post by ppaattrriicckk »

TheProbes wrote: post #735
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…

There's no such thing as a room temperature super-conducting magnet. You are talking about "high temperature" magnets, which are YBCO tape magnets. High temperature, in this case, means about -290 degrees F. The next breakthrough that will come will be YBCO powder-in-tube wires, that will allow much stronger fields than currently. They'll be here within a decade, probably much less, as working prototypes exist now.

Yeah, you're right. That was a typo and now I can't correct it.

I'm not sure what "high room temperature" would even entail :)

Re: Major breakthrough on nuclear fusion energy

#789

Post by Fredej »

_0ffh wrote: post #774
javajosh wrote: post #565

Earlier quoted context omitted.

According to the article, FLiBe has the same heat capacity of water, but a boiling point over 14x higher (1430 °C according to the article). Melting point is 359 °C, 3.5x higher. I will speculate that its basically used as a water coolant with the phase shifts shifted up and out. I bet the heat exchangers are exotic, too, having to operate at such high temps! In fact I'd expect to see a pretty sophisticated cascade o…

Nitpick, ratios of °C do not make physical sense. For ratios of temperatures you should first convert them to Kelvin, Rankine, or something similar. Accordingly, the ratio of 1430°C to 100°C is roughly 1703/373=4.6.

The ratio between waters melting and boiling point is amazingly high at 100°C/0°C!

Re: Major breakthrough on nuclear fusion energy

#790

Post by Inufu »

londons_explore wrote: post #753
javajosh wrote: post #565

Earlier quoted context omitted.

According to the article, FLiBe has the same heat capacity of water, but a boiling point over 14x higher (1430 °C according to the article). Melting point is 359 °C, 3.5x higher. I will speculate that its basically used as a water coolant with the phase shifts shifted up and out. I bet the heat exchangers are exotic, too, having to operate at such high temps! In fact I'd expect to see a pretty sophisticated cascade o…

Higher temperatures in the coolant loop are normally desirable for efficiency. In a heat engine, the hotter the hot side, and cooler the cold side, the more energy you can extract after all. I don't really see why it's important for a fusion reactor though, where efficiency isn't really a concern at this point.

Efficiency is the main concern for a fusion reactor!

We've known how to produce fusion reactions for a long time, the difficult part is to generate net energy.

Post reply on HN