Superconductor in vacuum chamber - low energy consumption solution?

[HarryHutton]

Hello all,

Superconductors are great, but obviously its tricky to keep them at such a low temperature for extended periods of time. This poses a problem for engineering applications.

What about the feasibility of cooling the superconductor, then placing the material in a vacuum chamber. Less collisions = less thermal energy. Shield the walls from radiation loss using suitable absorption such as lead or other, perhaps install a 2nd vacuum layer (double glazing as such), and voila - sustainable superconductors.
Not much can be done about dark matter or neutrinos, but as far as I'm aware they don't really interact with matter much anyway.

Thoughts?

 

[Drakkith]

It's probably cheaper and easier to just supercool them than to place them in a high vacuum.

 

[krd]

It's probably cheaper and easier to just supercool them than to place them in a high vacuum.

Yeah, well this kind of thing is a problem with the much heralded quantum computers.


The processor is really small, but have you seen the size of the fridge you need to keep it cool.

 

[Drakkith]

Yeah, well this kind of thing is a problem with the much heralded quantum computers.


The processor is really small, but have you seen the size of the fridge you need to keep it cool.

The same goes for the vacuum equipment you would need. They aren't small either.

 

[mfb]

Blackbody radiation is still present. Vacuum is a common solution to isolate cold things - look at the LHC magnets, for example, part of the largest cryogenic system on earth. In addition to other layers, vacuum is used as isolation.

Magnet design

In addition, there are some concepts to use vacuum as part of an isolation for houses (in small bubbles in the material, which are usually filled with air) - it reduces the required thickness of the isolating material a lot.

 

[NascentOxygen]

What about the feasibility of cooling the superconductor, then placing the material in a vacuum chamber. Less collisions = less thermal energy. Shield the walls from radiation loss using suitable absorption such as lead or other, perhaps install a 2nd vacuum layer (double glazing as such), and voila - sustainable superconductors.

Heat does not come in the form of high energy particles, so your lead shield is of no use. Vacuum is already used to surround the superconductor and its refrigerant, in the design of containment vessels (Dewars). For brief overview, read http://www.cryonics.org/cryostats.html

And by the way, HarryHutton, http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif

 

[HarryHutton]

Ah so its already in use? That's quite cool.

Reading that report, I am a little unclear. Is any power draw needed at all to keep the superconductors below critical temperature?

 

[ZapperZ]

I must say, I don't quite understand this thread and not sure if I read it right. And this is coming from someone who has dealt with "superconductors in vacuum" throughout my graduate and postdoc research.

If one cools down a superconductor, AND, in principle, leave it isolated in a UHV environment, then YES, it still will acquire heat from the surrounding and will bring it up above Tc. Why? Because the vacuum chamber surrounding it is at room temperature, and IR can still travel in vacuum! One can try doing the same popular "levitation" demonstration in vacuum and see how long it takes before the superconductor stops levitating, and it WILL stop levitating!

If one continues to cool it down via a system of cryogenics, then by definition, the superconductor is no longer isolated because of the cooling system is in contact with a bunch of other things.

So I'm not exactly sure what is being asked here.

Zz.

 

[NascentOxygen]

Ah so its already in use? That's quite cool.

Reading that report, I am a little unclear. Is any power draw needed at all to keep the superconductors below critical temperature?

The cooling mechanism is usually that you allow some of the gas (He) to boil off, and in doing so it carries away heat (as latent heat of vaporization) thereby chilling the remaining liquid He. This gradual loss means that periodically you must top up the level of liquid He. The better your insulation, the less often do you need to replenish the liquid He. So the "power" used is via imported liquified He.