Momentary fusion breakthroughs face hard reality
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Momentary fusion breakthroughs face hard reality
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Re: Momentary fusion breakthroughs face hard reality
#2There's a really good series on what's needed to build a working fusion reactor on the YouTube channel "Improbable Matter".
How nuclear fusion works (1) - fusors, thermonuclear reactions, lattice fusion: https://www.youtube.com/watch?v=2DzKXN1pcwY
How nuclear fusion works (2) - confinement, stars, nukes, inertial fusion energy: https://www.youtube.com/watch?v=mxmxZI2Ltvs
How nuclear fusion works (3) - magnetic confinement, tokamaks, stellarators: https://www.youtube.com/watch?v=gwOrbr8KWDs
How nuclear fusion (maybe) works (4) - reactor practicalities: https://www.youtube.com/watch?v=ZHmHBMaS6Sw
Strongly recommended!
Re: Momentary fusion breakthroughs face hard reality
#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 fuel pellets are also extremely expensive, says Kritcher, each one pricing in at an estimated $100,000. Then, producing a reasonable amount of power would mean dramatically increasing the frequency of NIF’s shots — a feat barely on the horizon for a reactor that requires months to load up the next nanosecond-long burst.
"months to load up" is even a euphemism - IIRC they have to repair parts of the lasers which are so overpowered that they damage their guidance optics with each blast. So the cost for one shot is even higher than the $100,000 for the fuel pellet and the cost of the energy consumed by the lasers. 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...
Re: Momentary fusion breakthroughs face hard reality
#4..using the laser approach. Other approaches don't have that issue:
https://www.iaea.org/newscenter/news/tokamaks-stellarators-l...
Re: Momentary fusion breakthroughs face hard reality
#5..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...
Re: Momentary fusion breakthroughs face hard reality
#6[deleted]
Re: Momentary fusion breakthroughs face hard reality
#7..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...
Well those of us who have never heard of "momentary fusion" read the title to mean "momentary breakthroughs in fusion"
Re: Momentary fusion breakthroughs face hard reality
#8The work from Rochester mentioned briefly is probably the second best performing fusion experiment and this was done with a laser that's at least 29 years old.
What the article doesn't mention is that the approach demonstrated could decrease the cost of fuel pellets. In NIF, the laser energy is converted to X-rays which compress the fuel pellet using expensive elements like gold. What they demonstrated is that the fuel pellet can be imploded directly with the lasers.
Re: Momentary fusion breakthroughs face hard reality
#9> 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 primary goal here. Looks like they did shift to plutonium targets for a while about a decade ago focusing more on weapons research but then shifted back to trying to work toward controlled ignition for power generation.
Still a long way to go but the first step is getting more energy out then in on the main reaction without using fission bombs and destroying the device. Then figure how to scale up to get more energy out than in when considering the apparatuses efficiency, then getting more out than in when considering heat engine efficiency.
Re: Momentary fusion breakthroughs face hard reality
#10> 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 electricity costs to reach $25 per MWh[1] with ICF. With the most important factors driving cost being achieving high gain and yield per shot
[0]https://ieeexplore.ieee.org/document/650904/
[1]https://royalsocietypublishing.org/doi/10.1098/rsta.2020.005...