Can Ferrofluids Be Used in Tokamak or Spheromak Fusion Devices?

[sanman]

Hi,

Is it possible to use a ferrofluid to create a tokamak/spheromak? If not, then why?

http://en.wikipedia.org/wiki/Ferrofluid

Ferrofluids can be composed of non-magnetic liquids containing magnetic particles in colloidal suspension.

 

[Astronuc]

No. Temperature.

 

[phyzguy]

What do you want to use the ferrofluid for? For generating the confining magnetic field? What advantages would it have over a simple coil?

 

[sanman]

Well, what I was thinking of, was the idea of using a burning plasma as rocket propulsion.

If you use an aneutronic fusion reaction to minimize harvesting losses, then you can recycle more energy back into the system.

So the idea would be to use the burning plasma as an "energy container" rather than as an energy source. You would charge it up with energy while on the ground, and then rely on that plasma to keep burning for the time it takes to reach orbit.

The idea would be to have a "disposable tokamak" which would be lighter in weight, and whose walls could be converted into exhaust gas by the burning plasma. Astronuc once said that the problem with nuclear rockets is in the "working fluid" (ie. the energetic nuclear material is not the same as the exhaust propellant material, and the bottleneck is in transferring power from one to the other). So that's where having liquid containment walls for your pseudo-tokamak would allow the supply of wall material to be replenished, while also serving as both propellant and "working fluid"

Perhaps I should have said "magnetic fluid" instead of ferrofluid. After all, the Earth's molten core has magnetism even while being at a high temperature, although it's much weaker magnetism than a tokamak. I was wondering whether a suitable choice of liquid, or else a suitable choice of colloidal material, could be used to achieve the same magnetic field as a tokamak, while also acting as propellant.

 

[alphy]

These particles are typically nanoscale and coated with a surfactant to prevent agglomeration. While ferrofluids have many interesting properties and applications in various fields, they are not suitable for use in a tokamak or spheromak due to a few key reasons.

Firstly, ferrofluids are not stable at high temperatures. Tokamaks and spheromaks operate at extremely high temperatures, typically in the range of millions of degrees Celsius. At these temperatures, the surfactant coating on the magnetic particles in a ferrofluid would break down, causing the particles to agglomerate and lose their magnetic properties. This would render the ferrofluid ineffective for use in a tokamak or spheromak.

Secondly, ferrofluids are not good electrical conductors. In a tokamak or spheromak, the plasma must be confined and controlled using strong magnetic fields. These magnetic fields would not be able to penetrate a ferrofluid, as it is not a good conductor. This would make it difficult to create and maintain the necessary magnetic fields for plasma confinement.

Lastly, the magnetic particles in a ferrofluid are typically too large to be manipulated by the magnetic fields used in tokamaks and spheromaks. These particles are typically on the nanoscale, while the magnetic fields used in these devices are on a much larger scale. This mismatch in size would make it difficult to control and manipulate the particles in a ferrofluid using the magnetic fields in a tokamak or spheromak.

In conclusion, while ferrofluids have many fascinating properties and applications, they are not suitable for use in a tokamak or spheromak due to their instability at high temperatures, poor electrical conductivity, and mismatch in size with the magnetic fields used in these devices. Other materials and methods are better suited for creating and controlling the plasma in these fusion devices.