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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

#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?

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

#5
Having read about tokamaks for thirty years, I'd be curious what specific breakthroughs and innovations have occurred since the 1980s, which lead to the optimism described in the article (which is otherwise frustratingly devoid of detail).

It's great there are seven-peer reviewed articles about SPARC, but plasma was not my specialty in physics -- would any specialists care to comment on whether there is anything particularly exciting here?

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

#7
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?

I think at least the sales pitch is that the new magnets is all you need, and apart from that it uses the same well-understood technology that ITER is based around.

https://www.psfc.mit.edu/files/psfc/imce/research/topics/spa...

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

#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 do you get the power out? The plasma heats up, but how do you turn that into useful electrical energy?

Nevertheless of course I hope it does work as advertised... someday.

Edit: thanks everyone for the thoughtful, insightful replies!

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

#9

Having read about tokamaks for thirty years, I'd be curious what specific breakthroughs and innovations have occurred since the 1980s, which lead to the optimism described in the article (which is otherwise frustratingly devoid of detail). It's great there are seven-peer reviewed articles about SPARC, but plasma was not my specialty in physics -- would any specialists care to comment on whether there is anything part…

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

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

#10
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?

There's some discussion about this in this[1] presentation which also mentions the SPARC reactor. My main takeaway is basically yes, high-temp superconductors got "mainstream" very quickly.

I'd recommend watching the whole thing, I found it quite interesting.

[1]: https://youtu.be/L0KuAx1COEk?t=2929

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