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Momentary fusion breakthroughs face hard reality

spectrum.ieee.org

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Re: Momentary fusion breakthroughs face hard reality

#11

Post by Manabu-eo »

rob74 wrote: post #5
1970-01-01 wrote: post #4

..using the laser approach. Other approaches don't have that issue: https://www.iaea.org/newscenter/news/tokamaks-stellarators-l...

I guess that's why they're using "Momentary Fusion" in the title? Of course, it wouldn't have hurt to mention in the article that other approaches which might be more feasible also exist...

I never heard the term "Momentary Fusion". There are other pulsed fusion methods, like Dense Plasma Focus[1] with it's very hot but very short lived plasmoids. Also still far from being economically viable, but I would say has a much better chance than that weapon research on NIF[2].

[1] https://en.wikipedia.org/wiki/Dense_plasma_focus

[2] https://spectrum.ieee.org/startup-lppfusion-embraces-instabi...

Re: Momentary fusion breakthroughs face hard reality

#13

Post by FourHand451 »

SigmundA wrote: post #9
rob74 wrote: post #3

> Plenty of other obstacles remain than those noted above, too. Current calculations compare energy generated against the NIF laser’s output, but that brushes over the fact that the lasers draw more than 100 times the power from the grid than any fusion reaction yields. That means either energy gains or laser efficiency would need to improve by two orders of magnitude to break even in any practical sense. The NIF’s f…

>I wonder why everyone skirts around the obvious here: the NIF's task is weapons research, and for that, fusion reactions which last nanoseconds might be enough, but there is no way this method can be scaled up so it's actually a cost-effective way of producing electricity... We already have fusion weapons that work very well, there is some valuable data that can aid weapons design I don't believe that to be a primar…

I think you may be slightly misinterpreting the parent comment. When they say the NIF's task is weapons research, I think they meant that the facility was built with that task in mind. When I read your comment it sounds more like you're talking about the current task of the people working there.

Both valid points of discussion, but different ones.

Re: Momentary fusion breakthroughs face hard reality

#14

Post by tonetegeatinst »

rob74 wrote: post #3

> Plenty of other obstacles remain than those noted above, too. Current calculations compare energy generated against the NIF laser’s output, but that brushes over the fact that the lasers draw more than 100 times the power from the grid than any fusion reaction yields. That means either energy gains or laser efficiency would need to improve by two orders of magnitude to break even in any practical sense. The NIF’s f…

I think a lot of people who are really into fusion research know that the military isn't going to be doing the same kind of fusion research as the groups looking into fusion as an energy source.

Is what they did interesting sure, but alot of people who actually follow fusion development know that this was a PR meme that some news stretched.

Fusion has always been 20 years away its a literal meme....and yet we are making good advancements in the field but I think anyone with a basic understanding or those who realized this was so short lived results time wise realised it was an overhyped thing by media from this group.

Fusion is important to the government because they can theoretically squeeze more power out of nuclear weapons, but due to the difference in timescale zit just dosnt translate across domains of military to public energy that well

Re: Momentary fusion breakthroughs face hard reality

#15

Post by JoeAltmaier »

tonetegeatinst wrote: post #14
rob74 wrote: post #3

> Plenty of other obstacles remain than those noted above, too. Current calculations compare energy generated against the NIF laser’s output, but that brushes over the fact that the lasers draw more than 100 times the power from the grid than any fusion reaction yields. That means either energy gains or laser efficiency would need to improve by two orders of magnitude to break even in any practical sense. The NIF’s f…

I think a lot of people who are really into fusion research know that the military isn't going to be doing the same kind of fusion research as the groups looking into fusion as an energy source. Is what they did interesting sure, but alot of people who actually follow fusion development know that this was a PR meme that some news stretched. Fusion has always been 20 years away its a literal meme....and yet we are mak…

The US military is very much interested in fusion, as an energy source.

The Desert Storm conflict cost something like $1T (yes a Trillion dollars) just for gasoline.

There was on this site a description of a military effort to create a low-yield fusion generator that would fit on a military truck. It only had to fuel a mobile camp, not a city. If I recall, it was something like the Lockheed plan, to create a vortex (not a torus) to stuff the fuel through a constriction and get some kind of fusion yield. Wasteful, but not as wasteful as $1T

Re: Momentary fusion breakthroughs face hard reality

#17

Post by LegionMammal978 »

JoeAltmaier wrote: post #15
tonetegeatinst wrote: post #14

Earlier quoted context omitted.

I think a lot of people who are really into fusion research know that the military isn't going to be doing the same kind of fusion research as the groups looking into fusion as an energy source. Is what they did interesting sure, but alot of people who actually follow fusion development know that this was a PR meme that some news stretched. Fusion has always been 20 years away its a literal meme....and yet we are mak…

The US military is very much interested in fusion, as an energy source. The Desert Storm conflict cost something like $1T (yes a Trillion dollars) just for gasoline. There was on this site a description of a military effort to create a low-yield fusion generator that would fit on a military truck. It only had to fuel a mobile camp, not a city. If I recall, it was something like the Lockheed plan, to create a vortex (…

That seems wildly high? The figure widely quoted for the total cost of the Gulf War is $60B in 1991 dollars, or $137B today, so clearly the gasoline costs alone can't exceed that number. It's only the extremely prolonged conflicts like the War in Afghanistan that get into the trillions of dollars total.

Re: Momentary fusion breakthroughs face hard reality

#18

Post by ess3 »

rob74 wrote: post #3

> Plenty of other obstacles remain than those noted above, too. Current calculations compare energy generated against the NIF laser’s output, but that brushes over the fact that the lasers draw more than 100 times the power from the grid than any fusion reaction yields. That means either energy gains or laser efficiency would need to improve by two orders of magnitude to break even in any practical sense. The NIF’s f…

This basically the plot of the movie ”Real Genius”

Re: Momentary fusion breakthroughs face hard reality

#19

Post by DennisP »

rob74 wrote: post #3

> Plenty of other obstacles remain than those noted above, too. Current calculations compare energy generated against the NIF laser’s output, but that brushes over the fact that the lasers draw more than 100 times the power from the grid than any fusion reaction yields. That means either energy gains or laser efficiency would need to improve by two orders of magnitude to break even in any practical sense. The NIF’s f…

Efficiency of equivalent lasers has improved by about 40X since NIF was built, and they seem to have nonlinear scaling on fusion output. NIF definitely isn't a practical energy system, but it is an experiment that helps move us in that direction.

Here's a NYTimes article[1] about various companies attempting laser fusion for power production. One of them has an approach very similar to NIF's, and a couple others are similar but do away with the need for a hohlraum by using a different type of laser. They also say:

"A decade ago, a report[2] by the National Academy of Sciences found much to like in the energy potential of laser fusion but recommended that the United States hold off major investments until ignition was achieved. That time is now."

[1] https://www.nytimes.com/2023/11/13/science/laser-fusion-ener...

[2] https://nap.nationalacademies.org/catalog/18289/an-assessmen...

Re: Momentary fusion breakthroughs face hard reality

#20

Post by megaman821 »

gene-h wrote: post #10
rob74 wrote: post #3

> Plenty of other obstacles remain than those noted above, too. Current calculations compare energy generated against the NIF laser’s output, but that brushes over the fact that the lasers draw more than 100 times the power from the grid than any fusion reaction yields. That means either energy gains or laser efficiency would need to improve by two orders of magnitude to break even in any practical sense. The NIF’s f…

NIF uses inefficient lasers because they were cheap to build at the time and because NIF is a science experiment. Lasers have gotten better. And lasers aren't the only way ICF fusion could be carried out, it may be possible to use ion beams instead[0]. It does not matter if fusion reactions last microseconds if they generate more energy. Using optimistic, but not unrealistic assumptions, it appears feasible for elect…

Those numbers don't seem feasible. Near as I can tell, a steam generator with a magical source of never-ending heat would cost $15/MWh. There is no way a high-tech facility and the personnel required to run it are costing $10/MWh.
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