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US Department of Energy: Fusion Ignition Achieved

energy.gov

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Re: US Department of Energy: Fusion Ignition Achieved

#131

Post by dsfyu404ed »

bmmayer1 wrote: post #103
jkelleyrtp wrote: post #33

> LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE) Yesterday, everyone was complaining about the 2.2:2.0 ratio, but now we're working with 3.15:2.05. With modern lasers, that'd be a total Q of 0.375 assuming 100% ef…

This is a stupid question but I don't know anything about fusion: How is it possible for X energy to create X+Y energy in output? Doesn't that violate some fundamental law of physics?

You know how when you burn something you release the energy in the chemical bonds?

Fusion and fission are like that but for atoms instead of molecules.

Re: US Department of Energy: Fusion Ignition Achieved

#132

Post by dogma1138 »

thehappypm wrote: post #45
brofallon wrote: post #30

I'm still a little unclear on the benefits that fusion offers compared to things like wind and solar. I understand that we need to develop better storage technologies for the energy produced by wind and solar, but that seems so much easier than the challenges currently facing fusion. Wind and solar just seem so far ahead of fusion already - they're pretty cheap and very widely deployed on a global scale. In compariso…

It’s potentially just a much better version of fission. Fusion won’t cause a runaway reaction — in fact it’s brutally difficult to get it to react at all, hence why this is an achievement. It also doesn’t use materials that can be used for a bomb, again unlike fission. As a result it has the potential to be cheaper to implement, cheaper to fuel, with no meltdown risk.

Depending on the scale and reactor design, we have really good examples of run away fusion reactions. Run away reactions are easy, controlled ones are hard.

And whilst I won’t doubt that if fusion ever becomes commercially viable the reactors would be walk away safe it doesn’t mean that you don’t need to account for that in your design.

Re: US Department of Energy: Fusion Ignition Achieved

#133

Post by Robotbeat »

sillysaurusx wrote: post #115
jkelleyrtp wrote: post #33

> LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE) Yesterday, everyone was complaining about the 2.2:2.0 ratio, but now we're working with 3.15:2.05. With modern lasers, that'd be a total Q of 0.375 assuming 100% ef…

This tweet claims that 500MJ of energy was required: https://twitter.com/latzenpratz/status/1602686252486217728 > "had to put 500 megajoules of energy into the lasers to then send 1.8 megajoules to the target - so even though they got 2.5 megajoules out, that's still far less than the energy they originally needed for the lasers," says Tony Roulstone of the University of Cambridge. But it's good to finally see progre…

That’s only because they’re using old school flash pumped lasers, not the new solid state lasers you’d use today if you wanted to make a power plant demo.

Re: US Department of Energy: Fusion Ignition Achieved

#134

Post by BudaDude »

mFixman wrote: post #104

Widespread energy generation nuclear fission is politically impossible in most Western countries. Why are people optimistic that fusion won't have the same kind of problems, such as new plants being too expensive to build and old obsolete plants being too useful to decommission?

I'm a bit more optimistic about this. This technology will be more important for space exploration than it will be (currently) on the ground.

Re: US Department of Energy: Fusion Ignition Achieved

#135

Post by valine »

thehappypm wrote: post #45
brofallon wrote: post #30

I'm still a little unclear on the benefits that fusion offers compared to things like wind and solar. I understand that we need to develop better storage technologies for the energy produced by wind and solar, but that seems so much easier than the challenges currently facing fusion. Wind and solar just seem so far ahead of fusion already - they're pretty cheap and very widely deployed on a global scale. In compariso…

It’s potentially just a much better version of fission. Fusion won’t cause a runaway reaction — in fact it’s brutally difficult to get it to react at all, hence why this is an achievement. It also doesn’t use materials that can be used for a bomb, again unlike fission. As a result it has the potential to be cheaper to implement, cheaper to fuel, with no meltdown risk.

Also don’t forget the biggest benefit over solar/wind: it keeps on generating power on cold windless nights.

Re: US Department of Energy: Fusion Ignition Achieved

#136

Post by a-priori »

bmmayer1 wrote: post #103
jkelleyrtp wrote: post #33

> LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE) Yesterday, everyone was complaining about the 2.2:2.0 ratio, but now we're working with 3.15:2.05. With modern lasers, that'd be a total Q of 0.375 assuming 100% ef…

This is a stupid question but I don't know anything about fusion: How is it possible for X energy to create X+Y energy in output? Doesn't that violate some fundamental law of physics?

It's not "creating" energy, it's releasing energy.

The original atoms (exactly which atoms depends on the reactor, but let's assume it's deuterium and tritium) have a certain starting energy. When you fuse them together the resulting atom (helium-4, if you start with deuterium and tritium) moves it into a lower energy state.

Since the fused atom has lower energy than the input atoms, the fusion reaction releases the difference in energy, which you can then capture.

Re: US Department of Energy: Fusion Ignition Achieved

#137

Post by Kubuxu »

wernercd wrote: post #75
panosfilianos wrote: post #61

Earlier quoted context omitted.

Would that mean that you wouldn't need titium to start with? Or that tritium deposits would replenish? How would it affect the rough calculations above?

I would also wonder if Titium is that expensive... and it generates titium... would that be part of the "break even" equation? Creating something rare to sell?

It is so rare because tritium is not found in nature in any significant quantity. The amount on the market comes from water recovered from water pools used for spent nuclear material storage.

There also is no enormous market for tritium. So in short, fusion reactors exist on both sides of the tritium market, by becoming the primary producers and consumers of it, which should lead to significant drop in price of tritium.

Re: US Department of Energy: Fusion Ignition Achieved

#139

Post by jerf »

simiones wrote: post #112
bioemerl wrote: post #20

Here's your most exciting paragraph > LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE). Many advanced science and technology developments are still needed to achieve simple, affordable IFE to power homes and busines…

That's a very apt analogy, as both this and Manhattan are weapons research programs. I'm not very excited in hearing we'll get even more powerful thermo-nuclear bombs.

Fusion bombs have existed since the early 1950s. Technology rapidly developed to the point that they can essentially be built to be arbitrarily large, far beyond any practical war purpose. There is no need for any larger bomb than what was built many decades ago. None of this research is necessary for bombs. All of the difficult problems fusion power generation faces with long-term plasma confinement go away when you're just trying to squeeze as hard as you can and are willing to use fission bombs to do it in an otherwise uncontrolled manner.

Re: US Department of Energy: Fusion Ignition Achieved

#140

Post by simiones »

UltraViolence wrote: post #85

I thought we had passed this mark a long time ago, but only during short stints. However, the way they're realizing it by shooting a fuel pellet with lasers is unsustainable and impractical IMHO.

If only they were shooting a fuel pellet: they are instead shooting a hohlraum, a precision-engineered piece of gold and that, in turn, shoots the fuel pellet with X-Rays, acting as a kind of aiming/synchronization device. The hohlraum is destroyed in the process, and currently costs millions of dollars to build a new one.
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