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Compact nuclear fusion reactor is 'very likely to work,' studies suggest

nytimes.com

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Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#51

Post by sbierwagen »

cultus wrote: post #14
jjoonathan wrote: post #9

Earlier quoted context omitted.

Superconductors recently got much better in a way that has cubic effect on reactor size.

I know essentially nothing about superconductors, but if they all have essentially zero resistance, what makes one better for this application? I thought the main advantage of high-temp superconductors was using liquid nitrogen instead of helium.

All superconductors superconduct, but there's wide variation in how strong of a magnetic field they can endure before leaving the superconducting state: https://www.researchgate.net/figure/Upper-critical-fields-an...

ITER (and the LHC) used NbSn magnets, since it was designed in the 90s. Newer designs will use newer superconductors.

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#54

Post by Florin_Andrei »

DataDaoDe wrote: post #48
Florin_Andrei wrote: post #40

Earlier quoted context omitted.

> this is still exciting given how anemic advancement in the fusion space has been for 50+ years At the top of my list for when I'll be king for a day is - massive, national-scale investments (think: reaching towards one percent of GDP) in fusion research. This is a major roadblock, but things look awesome on the other side. We just need to get our stuff together to hop over this fence somehow.

I couldn't agree more. Once you realize that energy is the fundamental unit which powers everything else in the economy, not only from every movement of ourselves to those of our machines as well, you realize the more we advance in our ability to produce more and more energy at cheaper and cheaper costs in increasingly reliable ways, the more we can accelerate, without exception, every other industry.

Make an efficient fusion reactor the size of a truck, and the solar system becomes your backyard.

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#55

Post by Zardoz84 »

willis936 wrote: post #19
isoprophlex wrote: post #8

I never quite understood the math behind power densities in a fusion reactor. In the sun, isn't energy production occurring at something like 100-1000 W/m3? So, if you want to build a multiple MW fusion plant, shouldn't these plants be ridiculously huge compared to, say, a wind turbine rated at a couple of MW? Is the density of the plasma so much higher in a fusion reactor? Also, something else I never grokked, how d…

The density is actually lower than the sun in magnetic confinement fusion (MCF) devices because we can’t squeeze plasma together as hard as the sun’s mass can. Inertial confinement fusion (ICF) can squeeze harder than MCF devices, but has serious unaddressed engineering issues. The trick is in higher temperature plasma. The sun fuses protium (lone protons). We don’t have the confinement necessary on Earth to do this,…

lithium blankets traps neutrons. Sadly, the reactor chamber becomes radioactive (but a short period radioactivity that only requires to store the contaminated chamber for decades)

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#56

Post by Retric »

DataDaoDe wrote: post #48
Florin_Andrei wrote: post #40

Earlier quoted context omitted.

> this is still exciting given how anemic advancement in the fusion space has been for 50+ years At the top of my list for when I'll be king for a day is - massive, national-scale investments (think: reaching towards one percent of GDP) in fusion research. This is a major roadblock, but things look awesome on the other side. We just need to get our stuff together to hop over this fence somehow.

I couldn't agree more. Once you realize that energy is the fundamental unit which powers everything else in the economy, not only from every movement of ourselves to those of our machines as well, you realize the more we advance in our ability to produce more and more energy at cheaper and cheaper costs in increasingly reliable ways, the more we can accelerate, without exception, every other industry.

There is ~zero expectation in the scientific community that fusion is going to be cheap at scale. It might eventually be cheaper than fission due to several factors. But, even that’s looking a long way off.

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#57

Post by correct_horse »

jhoechtl wrote: post #52

Honest question: Has man-made nuclear fusion ever happened? Or is it theory, happening on the sun?

Nuclear fusion happens in man-made thermonuclear bombs. I believe it also happens in research reactors that require more energy than they produce due to various inefficiencies.

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#58

Post by aaronblohowiak »

coldtea wrote: post #33
NikolaeVarius wrote: post #20

Earlier quoted context omitted.

You boil water from the neutrons/heat it creates.

So in the end it's a glorified boiler!

as far as i am aware, solar power is the only prevalent power source that does not derive from spinning a dynamo. Besides wind (and perhaps there, too) almost all of the force used to spin dynamos includes some kind of boiling (eg: dams happen to use the force of the water after the "boil"/evaporation, nuclear, coal, natural gas, etc are all steam-based thermo-mechanical power plants.)

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#59

Post by avmich »

tsomctl wrote: post #12
Someone wrote: post #4

“Sparc takes advantage of a newer electromagnet technology that uses so-called high temperature superconductors that can produce a much higher magnetic field, Dr. Greenwald said. As a result, the plasma is much smaller.” So, is this ‘just’ a matter of ITER being obsoleted by improvements in magnet tech before it is completed, or is there more in this design than scaling down ITER?

ITER isn't meant to be a practical design, it's for research. So it's not obsolete just because it's using inefficient magnets.

It could be argued that ITER is actually quite important in learning how to deal with high technical complexity in general. Probably a good reason by itself to keep working on ITER, ISS is way simpler in comparison.

https://en.wikipedia.org/wiki/ITER#Criticism

"The project however was significantly delayed at the design stage as result of purposeful decision to decentralize its design and manufacturing among 35 participating states, which resulted in complexity that was unprecedented but consistent with the initial ITER goals of creating knowledge and expertise rather than merely producing energy."

Re: Compact nuclear fusion reactor is 'very likely to work,' studies suggest

#60

Post by Someone »

tsomctl wrote: post #12
Someone wrote: post #4

“Sparc takes advantage of a newer electromagnet technology that uses so-called high temperature superconductors that can produce a much higher magnetic field, Dr. Greenwald said. As a result, the plasma is much smaller.” So, is this ‘just’ a matter of ITER being obsoleted by improvements in magnet tech before it is completed, or is there more in this design than scaling down ITER?

ITER isn't meant to be a practical design, it's for research. So it's not obsolete just because it's using inefficient magnets.

The article claims this design can easily be built before ITER is completed (5 years vs 15 years)

It also says it can be built much cheaper than the total cost for ITER.

The article doesn’t say it, but I would guess that it also can be built for less money than the money needed to complete ITER.

If so, what’s not obsolete about ITER? Are there useful experiments that can be done with it that one can’t do with a more modern design?

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