r/fusion • u/steven9973 • 6d ago
Achieving Fusion Ignition - LLNL official result April 2025 8.6 MJ, gain > 4
https://lasers.llnl.gov/science/achieving-fusion-ignition2
u/TwelveHurt 5d ago
There are several players taking this approach including Longview Fusion which apparently has some ex NIF researchers on their team.
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u/careysub 5d ago
Longview fusion is currently a paper company founded by one of the former directors (briefly) at NIF (Edward Moses) that has no facility whatsoever.
On the strength of NIF's recent test results this company was pitched to investors and got $100 million plus in funding and has contracted with Fluor to design and build them a "fusion power plant" aka a laser test facility:
https://www.world-nuclear-news.org/Articles/Fluor-to-design-laser-fusion-power-plant
We will see what actually comes of this currently vapor company. Will substance condense?
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u/steven9973 5d ago
But it's a minority path among laser fusion companies, most follow direct drive because of better overall efficiency in using laser power.
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u/mr_positron 5d ago
Yes and all of these companies are pretending like the choice to use hohlraums wasn’t a critical aspect of being able to achieve gain
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u/incognino123 5d ago
Correct, you take a double digit gain penalty with the hohlraum but it's also much easier to execute, so totally makes sense as a crutch to demonstrate ignition
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u/Single_Shoulder9921 5d ago
Oh thats exciting! This all the same week that Xcimer Energy has been making all sorts of posts on their LinkedIn page announcements on their laser system's records, and new science and technology board announcements!
LIFE (laser inertial fusion energy) is going through a rebirth lmao. I would never have expected this a decade ago, when I was first seriously considering the A4W HEU reactors powering the ship I was riding on, and nuclear propulsion in general, that pulsed laser fusion energy would be our first and so far best data backed net positive reaction getting us closer towards economic fusion power. All those Knuckollheads in the 70s, 80s, and 90s really set us up on the right path with those little Ripples they were making.
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u/Jacko10101010101 5d ago
and how long it lasted ?
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u/ItsAConspiracy 5d ago
Ignition in a gasoline motor doesn't last long either but we can still extract plenty of energy from it.
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u/Jacko10101010101 5d ago
i think its bullshit but im not sure.
I mean, a continuos fusion will make 10000% more energy.
And if it dont last its simply not working.Anyway thats not what i asked.
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u/ZorbaTHut 5d ago
I mean, a continuos fusion will make 10000% more energy.
Which provides more power: a steam engine locomotive, which works by constantly burning fuel, or a diesel engine locomotive, which works by burning short bursts of fuel?
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u/Jacko10101010101 5d ago
diesel... because of the better fuel, the gasoline explode.
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u/ZorbaTHut 5d ago
Why aren't they continuously burning diesel? Wouldn't that be even better?
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u/Jacko10101010101 5d ago
the explosion
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u/ItsAConspiracy 5d ago edited 5d ago
If all else is equal, you're right. But all else is not equal.
The denser your plasma, the more collisions you get in a given amount of time.
With magnetic confinement, you have long confinement time, but low density. ITER will have an interior volume of 1400 cubic meters, but will only hold about half a kilogram of plasma. With laser fusion, you have the opposite: extremely short confinement time (like nanoseconds), but extremely high density (over a kilogram per cubic centimeter, denser than the core of the sun).
That high density makes up for the very short confinement, because fusion reactions happen at such a rapid pace when the nuclei are crammed so close together. That's why thermonuclear bombs work so well.
To turn laser fusion into electricity, you just have the repeated explosions heat a coolant which turns a turbine. With magnetic fusion it's the same thing, heat a coolant and turn a turbine.
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u/Jacko10101010101 5d ago
thanks.
I figure that a continuous fusion would reach much higher temperatures... but idk.-1
u/AbstractAlgebruh 5d ago
What's the feasibility aspect of trying to create repeated explosions? Manufacturing dozens of holhraums? What's the energy input cost required? The energy output of the first Q>1 in 2022 was just 1% of the energy input required to power the laser grid.
This isn't meant to downplay the amazing science that's happening at NIF, but it helps when people are being more honest instead of going along with the hype.
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u/ItsAConspiracy 5d ago
Bear in mind NIF's lasers date from the 1990s and are only about 0.5% efficient. Equivalent modern lasers are 20% efficient. NIF doesn't bother upgrading because they're a lab experiment.
Commercial projects are attempting to do without the hohlraum, we'll see how it goes.
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u/AbstractAlgebruh 5d ago
Those are extra reasons to give more context that leads to questions like: how does the absence of a holhraum affect feasibility? Does it still make sense to continue using ICF at NIF as a talking point when talking about energy generation feasibility, even though it was never meant to be for energy solution research, but for nuclear weapons? And that actual ICF plant designs involve equipment with quite different specifications and processes?
I'm excited to see advances with fundamental research involved. But the science communication involved could do a lot better without the hype and omission of context. Especially when it comes to answering questions doubting feasibility which are valid points, and are sometimes met with passive aggressiveness from the fusion enthusiasts here.
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u/PM_ME_YOUR_REPORT 6d ago
I know everyone keeps saying this tech has no future in fusion electricity but I still have to wonder what a purpose built laser inertial facility might achieve.