Not quite superconducting wires

Discuss how polywell fusion works; share theoretical questions and answers.

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D Tibbets
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Joined: Thu Jun 26, 2008 6:52 am

Not quite superconducting wires

Post by D Tibbets »

Mmm.... I wonder if this would have any application in the Polywell non superconducting magrid. A 10 fold decrease in Ohmic heating (and related current) would ease cooling concerns considerably. The packing fraction of wires in the magrid cans (from M. Simon's suggested ~ 40%) might be increased to 60 or even 70%. This could result in stronger B fields in smaller packages, and also decrease the magnet current required. Using the JET Tokamak example. I believe they needed upwards of a gigawatt of current to power their magnets. Reducing that magnet input power to ~ 100 MW has all sorts of benefits.

Joel Roger's conservative B field limits useable with copper wire Magrids could be multiplied by as much as 5 to 10 times at the same current (and Ohmic heating). Suddenly, 10 Tesla fields become (almost) trivial, without having to resort to super conductors. Of course survivability, etc concerns may cause problems, but since the meta material is nanotechnology, as opposed to molecular scales for super conductors, I wonder if the metamaterial would be more resistant to x- rays, neutrons, etc.

http://www.physorg.com/news/2012-02-exo ... afely.html
"The metamaterial should be able to increase the magnetic force without increasing the electric current in the source coil," Urzhumov said. "The phenomenon of magnetostatic surface resonance could allow magnetic levitation systems to increase the mass of objects being levitated by one order of magnitude while using the same amount of electricity."
Dan Tibbets
To error is human... and I'm very human.

DeltaV
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Joined: Mon Oct 12, 2009 5:05 am

Post by DeltaV »

The preprint: Magnetic levitation of metamaterial bodies enhanced with magnetostatic surface resonances

This effect is based on "resonant enhancement of the magnetic polarizability", implying non-static fields.

The minimum frequency seems to be about 1 MHz for PCB (Printed Circuit Board) metamaterials:
The operational band of negative-μ PCB metamaterials can be easily adjusted to any frequency between roughly 1 MHz to about 100 GHz, even without conceptual changes in the PCB fabrication process, by adjustments to the unit cell size, as well as inductance and capacitance of the resonating metamaterial elements.
Interesting...

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