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Author Topic: Are superconducting magnets permanent?  (Read 2630 times)

Offline Geezer

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Are superconducting magnets permanent?
« on: 02/10/2010 21:11:42 »
Are superconducting magnets permanent magnets, or are they really electromagnets?


 

Offline syhprum

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Are superconducting magnets permanent?
« Reply #1 on: 02/10/2010 21:41:15 »
superconducting magnets are electromagnets but provided they are maintained at the correct temperature they behave like permanent magnets in as much as after the current to create the magnetic field has been injected into them it will continue to circulate with no loss of power due to their zero resistance.
 

Offline Geezer

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Are superconducting magnets permanent?
« Reply #2 on: 02/10/2010 21:44:07 »
So, in a sense, we could almost say that they are both.  :D
 

Offline syhprum

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Are superconducting magnets permanent?
« Reply #3 on: 02/10/2010 22:09:03 »
I think they could be most correctly classed as electromagnets as they contain no aligned electron spins, the field is generated by the current flowing in the coils any iron etc used in their constrution is only there for support.
 

Offline Geezer

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Are superconducting magnets permanent?
« Reply #4 on: 02/10/2010 22:36:25 »
I think you are correct, although, I suppose it depends a bit on the definition. If it's simply a magnet that has no external power source, a superconducting magnet is a permanent magnet, as long as you don't let it warm up too much, which isn't so different from the more traditional permanent magnet except for a slight difference in temperature.
 

Offline JP

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Are superconducting magnets permanent?
« Reply #5 on: 03/10/2010 08:40:05 »
It depends on your definition of permanent, but for most uses, you'd have to continue pumping in energy to cool it, so without external energy, it would stop superconducting.
 

Offline SeanB

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Are superconducting magnets permanent?
« Reply #6 on: 03/10/2010 11:24:56 »
In deep space, a superconducting magnet is permanent, providing it is protected from heating above the transition temperature of the particular material. If you used the modern materials that work in liquid nitrogen then all you would need is a simple sunshade or a few layers of reflective insulation to keep it so. Would be a good energy store out in the asteroid belt.
 

Offline Murchie85

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Are superconducting magnets permanent?
« Reply #7 on: 03/10/2010 12:19:55 »
Of course the holy grail is to find a material that can act like a super conductor at higher temperatures and progress is being made in that field so it may have more common applications than we think.
 

Offline lightarrow

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Are superconducting magnets permanent?
« Reply #8 on: 03/10/2010 14:26:31 »
I think a superconducting magnet is nothing else than a device able to produce high fields because of high currents; If you switch off the current, you switch off the magnetic field, so it cannot be a permanent magnet, just for this reason. The material is, for example, Niobium-Titanium or Niobium-Tin alloys, which are just conductors.
« Last Edit: 03/10/2010 14:34:48 by lightarrow »
 

Offline Geezer

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Are superconducting magnets permanent?
« Reply #9 on: 03/10/2010 19:12:54 »
I think it's reasonable to say a permanent magnet is a magnet that does not consume electric power to maintain the magnetic field, as that is what distinguishes it from an electromagnet. Therefore, a superconducting magnet is a permanent magnet as it does not consume electric power to maintain the magnetic field.

The temperature aspect is a "bum steer", because traditional permanent magnets also depend on temperature to maintain their field.

Anyway, that's my "theory" and I'm sticking to it (until my field collapses) ;D
 

Offline tommya300

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Are superconducting magnets permanent?
« Reply #10 on: 04/10/2010 05:43:30 »
This video explains a bit of what Geezer is saying

http://nextbigfuture.com/2009/10/magnifye-powerful-17-tesla.html

Of course the holy grail is to find a material that can act like a super conductor at higher temperatures and progress is being made in that field so it may have more common applications than we think.

Searching I tripped over a hot item

http://en.wikipedia.org/wiki/Yttrium_barium_copper_oxide
« Last Edit: 04/10/2010 06:13:12 by tommya300 »
 

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Are superconducting magnets permanent?
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