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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

#631

Post by boc »

LarryMullins wrote: post #559
boc wrote: post #450

Earlier quoted context omitted.

Quoted post unavailable.

Your "honest feedback" is nothing more than naked insults. Sillysaurusx is right. The "impossibly complex" matter is actually quite simple, Q=1 is little more than a psychological milestone, not some sort of technical tipping point where further progress becomes easier. And they haven't even gotten to Q=1 unless you buy into the justifications they give for dodgy accounting of the energy they put into it. The "imposs…

When a baseball batter hits a ball at a record 120mph, you calculate the impulse of force (∆p) they put into the swing to cause that result, not the total calories the player consumed during the past year in order to build their muscles.

You're arguing that the process of charging some inefficient lasers (aka eating food throughout the year) is invalidating this entire result. That was never part of the experiment, nor is it relevant to this test.

I understand exactly what you wrote above, and I'm telling you that it's not relevant to this discovery. You're arguing a non-sequitur in the classic definition.

Re: US Department of Energy: Fusion Ignition Achieved

#632

Post by jasonhansel »

_a_a_a_ wrote: post #295
belval wrote: post #280

Earlier quoted context omitted.

This was explained by another commenter yesterday, but this is not an issue. The 3.15:2.05 ratio is the news as it is the part that was difficult to achieve. The 300MJ accounts for significant laser inefficiencies in much the same way that the 3.15MJ of output won't convert to 3.15MJ of electricity as the conversion is not loss less. In other words: it's a net-positive output for that reaction, not the whole process,…

Granted... > in much the same way that the 3.15MJ of output won't convert to 3.15MJ of electricity as the conversion is not loss less ...and very much touche! That's a good point. But I do feel the overall loss should have been made clear and distinct from the gain in one part of the whole. Gross vs net perhaps?

IIRC part of the issue is that NIF's lasers are very old and much less efficient than more modern ones. So the 300 MJ needed to power the lasers is higher than would be expected if this were commercialized.

Re: US Department of Energy: Fusion Ignition Achieved

#633

Post by kennend3 »

SiVal wrote: post #612
eklitzke wrote: post #262

Earlier quoted context omitted.

Tangentially related, but I think this is an interesting fact, all the atoms in our universe/galaxy/solar system with a mass up to that of iron are formed in the core of stars in stellar fusion. Hydrogen fuses into helium, and as a star nears the end of its lifetime you get heavier elements like lithium, carbon, and so on. Under normal stellar fusion no elements heavier than iron will be produced, and iron is only el…

Iron is always spoken of as the dividing line, but I'd like to know whether iron is exactly on the line, on one side (which?), or it depends. IOW, does fusion of iron atoms release energy (hydrogen side of the line), absorb energy (uranium side of the line), neither, or either (depending on conditions)?

My son has a masters in nuclear physics and i've always been curious as to why iron causes stars to explode.

He does an excellent job explaining things and put it to me like this.

Elements to the Left of Iron can undergo fusion and release energy, Elements to the right can undergo fission and release energy.

Iron IS the line because it needs energy to do either of these.

All elements want to find stability, and Iron is that Element because it needs energy for either fission or fusion.

So yes, Iron is the dividing line and this is what makes it so stable.

Edit: forgot to link the chart when referencing left or right..

http://www.splung.com/content/sid/5/page/benergy

Re: US Department of Energy: Fusion Ignition Achieved

#634

Post by whiplash451 »

adventured wrote: post #317
chasd00 wrote: post #149

Earlier quoted context omitted.

> Who are our modern J. Robert Oppenheimer, Enrico Fermi, Richard Feynman, Edward Teller, John Von Neumann, and Stanislaw Ulam? they're working on getting you to click on an ad

> they're working on getting you to click on an ad They're not, and there's zero evidence to back that frequently floated premise up. That's a particularly laughable myth created by those same industry people to feel better about their terrible life choices. If you can't do something meaningful, at least you can pretend to be a genius doing nothing meaningful. It turns out that both things are false, they're not bril…

Wow. That was long overdue. Thank you!

Re: US Department of Energy: Fusion Ignition Achieved

#635

Post by jasonhansel »

lostmsu wrote: post #462
readams wrote: post #65

Earlier quoted context omitted.

This works in a totally different way, by heating a tiny target fuel pellet with a laser to cause it to collapse and trigger fusion through basically heating and squeezing: more like how a bomb works. It's not easy to see a direct path from this approach to a power plant, but it might involve lining up a steady stream of fuel targets and doing this in a sort of pulsed mode. Other approaches attempt to create a contin…

In principle inertial confinement is not much different from internal combustion engines where piston compresses the mix, and the explosion energy is harvested. Here lasers compress the mix, and the explosion energy is not yet harvested (but measured). Tokamaks (the other approach) are more like jet engines in that they sustain burning. But currently the burning in tokamaks requires more energy than it generates.

Could it be argued that we should invest more in ICF and less in tokamaks, given this result? I don't know enough about the field to say.

Re: US Department of Energy: Fusion Ignition Achieved

#636

Post by opportune »

markasoftware wrote: post #625
opportune wrote: post #584

Earlier quoted context omitted.

100% agree. We should be dumping as much as we can in getting fusion up and running ASAP. It could be a silver bullet to stop climate change alone, and by driving energy costs lower, enable huge innovations in AI/automation and increasing material wealth. $1T to move fusion forward just 5 years from eg 2040 to 2035 could alone have a huge ROI in terms of climate mitigation and decarbonization

Will not be a silver bullet, electricity production contributes less than half of global CO2 emissions. Still need other solutions for transport, industrial processes, agriculture, etc. Further, it's possible that fusion plants might be prohibitively expensive to build and maintain, even if their fuel is cheap.

I’m not thinking about just replacing grid energy, but carbon removal. If we can get fusion scaled up and efficient it should be no sweat to use it to just remove carbon from the air

In fact carbon removal might be a great way to subsidize fusion at the outset so that it can be overprovisioned/have a guaranteed minimum price

Re: US Department of Energy: Fusion Ignition Achieved

#637

Post by over_bridge »

Are there any thoughts on how this will become a power plant yet? It's awesome to see it filled up, reacted and then reset as a proof of concept, but can it ever be a continuous flow through the chamber without losing that ignition temp? Or will it be more like a 4 cylinder engine where each reactor is at a different stage of being filled, heated, reacting and emptying, with the net result being continuous?

Edit: Taking the internal combustion metaphor further, I'm imagining these connected in a circle. The grid is the starter motor to power the first laser, then each active chamber powers the laser on the next one (probably by capacitor not directly). Thus the energy production moves around the circle with each chamber being flushed and refilled before the laser powers back on. How far off is that image in my head? I've never actually seen it described

Re: US Department of Energy: Fusion Ignition Achieved

#638

Post by poopbutt6 »

w0mbat wrote: post #577
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…

Their total power draw from the grid was 300 megajoules and they got back about 3 megajoules, so don't start celebrating yet. Source: New York Times.

I agree! These results are NO cause for celebration. To do so would be deliberately misleading, and potentially devalue celebrations in general.

Re: US Department of Energy: Fusion Ignition Achieved

#639

Post by cheriot »

w0mbat wrote: post #577
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…

Their total power draw from the grid was 300 megajoules and they got back about 3 megajoules, so don't start celebrating yet. Source: New York Times.

I think the "With modern lasers" part is addressing that.

Re: US Department of Energy: Fusion Ignition Achieved

#640

Post by nrki »

Aeolun wrote: post #623
jcarreiro wrote: post #304

Earlier quoted context omitted.

Because they are researching inertial confinement fusion, not trying to build a working power plant. The efficiency of the lasers doesn't matter, since it doesn't affect their research.

Is energy on the order of 300MJ so cheap? You’d think that cutting it down to 150MJ would allow them to do more experiments.

300MJ ~= 83kWh which is like, $2000 in CA
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