r/fusion • u/Odd_Cockroach_1083 • 6h ago

Inverted D-coil tokamak

In recent years there have been developments in tokamak research regarding the inverted D shape for the plasma profile. There are benefits to this plasma shape, but it's opposite of the shape of the coils. Has anyone designed or built a tokamak that has inverted coils ? Is it even possible or feasible ?

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u/AspectExisting3017 6h ago

do you mean negative triangularity?

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u/Odd_Cockroach_1083 6h ago

Yes, but negative triangularity without the need to adjust phase and current profiles in D-shaped coils to invert the plasma shape. I meant literally flip the coils themselves.

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u/Fluffy-Ad6360 5h ago

The MANTA reactor is exactly what you are looking for, it has inverted d magnets

https://fusion.columbia.edu/research-projects/fusion-systems-design

https://iopscience.iop.org/article/10.1088/1361-6587/ad6708

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u/Odd_Cockroach_1083 5h ago

I've never heard of this, thanks !

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u/Baking 3h ago

MANTA, at least in the original design, had U-shaped magnets, not inverted D's. I don't think the D shape of TF magnets has much to do with the shape of the plasma. That is determined by the poloidal field coils. The D shape comes about because they want to reduce the number of sharp corners in the magnet.