
A Simple Fusion Recipe - fpoling
https://www.nature.com/articles/d41586-020-00745-7
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amelius
Sadly, I'm surprised nobody patented the idea of "using natural magnets in a
fusion reactor".

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FiatLuxDave
That's probably because there is way too much prior art. We used NeFeB magnets
in my fusion reactor... in 1995. I'm sure we weren't the first.

The insight that Zarnstorff had wasn't that permanent magnets are strong
enough to help fusion (neos aren't significantly stronger than they were a few
decades ago), it was that the poloidal field twist in a stellarator could be
assisted by permanent magnets, saving energy.

You may be familiar with donut-shaped tokamaks. To work, a tokamak has to have
a field in both the toroidal (around the donut hole) and poloidal (up through
the donut hole) direction. This causes a twist in the region where the plasma
is. There are a number of ways to make the poloidal field; the classic way is
to run current through the plasma.

A stellarator has magnets that already incorporate that twist in their
magnetic field, so they don't need current in the plasma to supply it. What
this paper is about is using permanent magnets to supply some of the field
needed for that twist instead of using the main magnets, so you can use fewer
or weaker main magnets.

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the8472
This is a bit light on details. Not even a link to a paper or anything.

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throwanem
Sure there is. But it's styled not to look like a hyperlink, because that's a
good idea? Anyway,
[https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.12...](https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.124.095001)

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jessriedel
I guess it lets Nature say they always link to the papers they discuss while
minimizing outbound traffic to competitors. Ugh.

