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US scientists achieve net energy gain for second time in a fusion reaction
(www.theguardian.com)
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this post was submitted on 06 Aug 2023
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Oh for goodness sake. 400MJ in for 3.15MJ out is not a net energy gain. I wish just once they'd be honest about what they do, it's ok to do basic physics research without pretending you've saved the world every six months.
Where do you get those numbers from? They don't seem to match the figures in this article or the article it links to. I get that you're saying they leave out some important facts about the total energy used in the experiment, but I'm curious about exactly what's not documented here.
Wikipedia's figures for the last time they made this claim. The exact figures might be a bit different this time round, but I doubt they've found 99% efficiency gains. Livermore sends out this sort of press release pretty regularly and it always comes down to the same creative accounting
Basically, there's a whole load of input energy that they just don't count. Heat? Doesn't count. UV? Doesn't count. Plasma? Doesn't count. this diagram from the wiki might be instructive. There may be decent justifications for counting it like this - I don't know, I'm not a nuclear physicist. But I think the way they continue to report it to the media is simply dishonest.
The logic is that they don't count ignition costs because they only have to be paid once. So it's producing more than it consumes, and would eventually start netting a surplus.
Except it's not and it won't. It's just a fraction of a second pop and done. There's no sustained reaction because inertial confinement by it's nature is extremely temporary, and there's no way to introduce new fuel. If they do some monster fuel pellet that outshines the laser then sure - they can claim a net surplus. If they find some contrivance to keep a reaction going after it's started then fantastic, well done, the day is saved. But they're not likely to do that at the NIF because, shhh! NIF is not really about generating energy.
Except this one isn't basic physics research. It's an end run around nuclear weapons treaties to test how missiles and planes respond to H-bombs going off nearby.
It could have an energy application (maybe), but given that the targets are ludicrously expensive, the most viable power plant would resemble the attempts in the 60s to use bombs in underground caverns to heat things up and put essentially a geothermal plant on top. Except with a laser detonator rather than a fission one. Chances of making it economically viable or reliable are slim.
Yeh that was me being circumspect. Last time i called it a weapons facility I got one of the researchers in my replies complaining that they totally intend to get round to some energy research one of these days. He didn't bother to correct any of the people in the same thread who were excited about their fusion power dreams finally coming true.
It's a shame. Blasting tritium into a mini sun with a massive frikken laser is plenty cool without having to misrepresent it so much.
Would you mind expanding on your first part, please? That sounds interesting and I haven't seen anyone else say anything about it. I'd like to know more.
This research comes frim the llnl weapons complex: https://wci.llnl.gov/
There is an international treaty against nuclear arms testing, so as new weapons and platforms are developed there is no way to expose them to the conditiona they'd encounter if they actually had to deploy nuclear weapons (or operate in an environment where they are being used such as trying to take out the other bomber that is on its way to destroy your other city while the first city burns).
In addition to the enormous military budget, They take large quantities of civilian money via the DOE because they pay lip service to it being "energy research". This is the part that is objectionable.
It's a cool thing, and arguably necessary given we recently got to see what happens when a country bordering Russia gives up its nuclear weapons altogether, but there is little application for energy. It may also see the development of some micro-fusion warhead with no fission component which is technically a nuclear bomb, but nigh-impossible to make if you don't have the US military budget so they'll use it anyway and say "nuh-huh!" when anyone objects.
Either the technology is highly limited in the volume where the reaction is self sustaining, so the machine as a whole will never break even energy-wise, or it is not, and every inertial confinement generator produced is essentially a weapon of mass destruction that the US will never let exist outside of the control of nuclear armed countries.
There may be some limited application to energy, but it's a stretch (essentially it would look like asking the US military nicely to come set another bomb off in your artificial geothermal reservoir every few months). It will certainly never be deployed in a non-military mobile application (which rules out most of the use cases where renewables are not strictly superior).
Very interesting, thank you.
NIF is used to test nuclear weapon stock piles without actually detonating them as a test. This is in compliance with the START treaties
https://www.govinfo.gov/content/pkg/CHRG-111shrg65071/html/CHRG-111shrg65071.htm You can search "ignition" for the couple references.
Cool stuff, thank you.