Liquid Super Magnets... The Future?

[Spacescifi]

 

These are the limits of making uber electromagnets as listed below:

Increasing current density is limited by Joule heating and increasing the magnetic field strength is limited by the cost, size and weight (as well as technological limitations) of electromagnets and the power available to feed them.^[14][15]

Cost is only an artificial factor, but the others are serious show stoppers.

Why do I even care about magnets? Powerful magnetic fields can be used for many scifi technologies... like rocketry and maybe... just maybe... get a profitable fusion reaction going.

One site claims scientists created a solid state electromagnet that can do 90 Tesla, although it will break itseld in time.

 

So I thought... are magnetic fluids possible? Uber magnetic fluids?

 

Does current physics understanding allow for it?

Because if so perhaps that is what we will use in the future. Since I really don't know how you would break a super magnetic fluid beyond boiling it.

 

You may discuss.

 

EDIT: Wow.... I suspected as much.

 

https://www.google.com/amp/s/www.sciencealert.com/scientists-have-printed-droplets-of-permanently-magnetic-liquid-and-boy-is-it-trippy/amp

Edited November 20, 2019 by Spacescifi

[farmerben]

Superconducting electromagnets have other constraints as well.  There is a critical magnetic field beyond which superconductivity collapses, depending on the material and temperature.  

Liquid ferromagnets, I'm skeptical about.  But Iron oxide nanoparticles suspended in oil is another thing.  They are in used motor oil.

 

 

[wumpus]

From memory, aligning the iron atoms (in solids) gives you at most 1 Telsa of field (iron amplifying a magnetic field).  I can't imagine a significant advantage in going to liquid.

And while superconductors have specific magnetic field limits, they also have specific current limits as well.  So if you need cheap or efficient magnetic fields you face stark limits as well while building a superconducting magnetic field.  Note that I suspect that this is more "the future" than any massive magnetic field (outside of fusion reactors).  Simply scale up your magnets to give you the force needed at reasonable fields and don't bother with multiple Tesla fields (some rare earth magnets go a bit higher than 1T, but not that much).

[Spacescifi]

1 hour ago, wumpus said:

From memory, aligning the iron atoms (in solids) gives you at most 1 Telsa of field (iron amplifying a magnetic field).  I can't imagine a significant advantage in going to liquid.

And while superconductors have specific magnetic field limits, they also have specific current limits as well.  So if you need cheap or efficient magnetic fields you face stark limits as well while building a superconducting magnetic field.  Note that I suspect that this is more "the future" than any massive magnetic field (outside of fusion reactors).  Simply scale up your magnets to give you the force needed at reasonable fields and don't bother with multiple Tesla fields (some rare earth magnets go a bit higher than 1T, but not that much).

 

If that is reality, then you can also nearly forget fusion rockets, as the magnetic fields to contain the reaction would be lab facility size anyway.

You can also forget any MHD ionocraft drive scaled up for the same reason.

[wumpus]

Nobody seems interested in scaling up current ion engines.  I really haven't looked into deeply the issues of why, but field strength and density (especially density) play a huge part.

Lab facility sized fusion will likely be the minimum size for fusion plants for the duration of the century.  And even then I'd suspect that they are using >1T fields (but probably still single digit).  A great example is the worlds most "powerful sustained magnet" (45T).  It is 32mm wide (the magnetic bore), requires 35 tons of plumbing, and 30MW of power to work(note that 33T of that isn't going through superconducting wires, probably the reason for a lot of the power and cooling).  Not something I'd try to put into orbit.

https://nationalmaglab.org/about/around-the-lab/meet-the-magnets/meet-the-45-tesla-hybrid-magnet