Superconductor breakthrough could power new advances (w/ Video)

Jul 09, 2010
Superconductor breakthrough could power new advances

 (PhysOrg.com) -- The first batch of a new range of powerful superconductors which could revolutionise the production of machines like hospital MRI scanners and protect the national grid has been developed by scientists.

Engineers at the University of Cambridge used new techniques to manufacture high-temperature superconducting materials, producing samples that can carry record quantities of electrical current for their type and size.

The breakthrough has improved the effectiveness of yttrium barium (YBCO) and a related family of superconducting materials. It raises the prospect of more powerful and affordable samples that could have huge benefits in a number of fields.

Researchers discuss these possibilities and demonstrate some of the materials' remarkable in a short film released today.

This video is not supported by your browser at this time.

are materials which, when cooled to a certain temperature, can carry an electrical current without losing energy in the process. This makes them different from standard conductors, such as , which resist the flow of current with the result that some energy is lost.

In the long term, this means that superconductors could have important environmental benefits by increasing energy efficiency. At the moment, up to 10% of the generated by British power stations is lost before it reaches the user because of resistance in the power lines. Superconductors offer no such resistance, could be used to store large quantities of energy until needed and in some cases can carry 100 times more current than copper.

The current also generates a , which means that superconductors can be used in numerous other applications. These potentially include MRI scanners in hospitals, "magnetic separators" which cleanse sea-water and lakes, high-speed monorail trains, mechanical flywheels that store energy and, famously, the Large Hadron Collider.

At present, however, effective superconductors are often expensive and difficult to mass-produce. The Cambridge research could be a step towards resolving this, by providing the basis for the development of more powerful samples that can be manufactured using a commercially compatible process.

That would drive down the production costs of machines that rely on the materials. MRI scanners, for example, which can cost around £1.5million each, could eventually become a common sight in GP's surgeries, helping to improve accurate detection and diagnosis of problems ranging from twisted knees to brain tumours.

In addition, superconductors can act as "fault current limiters" within the national grid, protecting it from the energy surge caused by a sudden rise in consumption. These surges, which caused blackouts across the east coast of the US in 2003 and Europe in 2006, can cause lasting damage to both the grid and public infrastructure. Superconducting materials will cease to conduct without significant energy loss if there is a particularly large current, however, meaning that they can be built into the system to shut down the electricity before it reaches the point of use.

"The potential advantages of developing viable high-temperature superconductors are huge," Professor David Cardwell, head of the bulk superconductivity group at the University's Department of Engineering, where the research took place, said. "The processes we have developed and patented should enable us to develop samples that are better, bigger, cheaper and more reliable."

While some materials need to be cooled down to as low as -269 degrees centigrade to superconduct, YBCO does so at the comparatively "high" temperature of -181 degrees C. This means that it can be cooled with liquid nitrogen, rather than liquid helium, which makes it cheaper to operate.

In the past, however, producing effective bulk superconducting devices from the material has proved difficult. YBCO is processed most easily in the form of a polycrystalline ceramic, but has to be manufactured as a single grain in order to generate large magnetic fields since boundaries between grains limit the flow of current in the bulk sample.

In addition, microscopic defects within the material can impede, or 'pin' the motion of magnetic flux lines and increase the flow of current through it. The distribution of these lines within a bulk superconductor has to be managed to maximise the flow of current and therefore the field.

The Cambridge team have developed a technique to manufacture large single grains of bulk superconductors that involves initially heating the material to a temperature of 1,000 degrees C, causing it to part-melt. In a series of experiments, various elements, such as depleted uranium, were then added to the chemical composition of the superconductor to generate artificial flux pinning sites within the single grain.

When the material cooled and reformed, these added materials retained their integrity and formed physical obstacles that form direct the motion of magnetic flux lines, enabling larger currents to flow.

In addition, the team developed a technique for fabricating large, single grains of bulk superconductors in air, using a new type of seed crystal that they have also patented, which enables much more scope for optimising the partial-melt process. Together, these techniques led to the production of samples far more powerful than those fabricated by more standard techniques, which exhibited record energy densities and magnetic fields for their size.

"The properties these samples exhibit could in time offer huge commercial potential by improving or reducing the weight and size of applications such as energy storage flywheels, magnetic separators, motors and generators," Professor Cardwell added. "These devices already use superconductors to varying degrees. With these new bulk processing techniques, we could greatly improve their power and potential."

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User comments : 26

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fmfbrestel
2 / 5 (1) Jul 09, 2010
Wow, unless I'm not reading this right, this could be a very significant advance. While i would like more hard numbers on just how much more current is allowed to pass, the fact that the current increase is coupled with a production cost decrease makes this a very important advance.
fmfbrestel
not rated yet Jul 09, 2010
darned sweet video of the guy playing around with his YBCO too!
DaveGee
not rated yet Jul 09, 2010
Superconductors offer no such resistance, could be used to store large quantities of energy until needed and in some cases can carry 100 times more current than copper.


Store large quantities of energy until needed???? While I'm very far from an expert WRT super conductor properties but can they really be used to STORE large quantities of energy?
Parsec
5 / 5 (5) Jul 09, 2010
DaveGee - its easy to imagine a energy storage device. Just induce a very large current in a superconductor ring. The current circulates without change until its needed, then interrupt the flow and suck out the current. The more current and the smaller the ring, the more storage capacity you get.
Caliban
not rated yet Jul 09, 2010
@Parsec,

Now, imagine that superconductor ring housed within a wound coil of copper wire -induced current for free. How about that! Need the cheap materials, first, though...

What I want to know is, what is the operating temperature? Any of these materials that have to be cooled significantly are simply unworkable. What is truly needed is a real room-temperature superconductor.

trekgeek1
3 / 5 (2) Jul 09, 2010
@Parsec,

Now, imagine that superconductor ring housed within a wound coil of copper wire -induced current for free. How about that! Need the cheap materials, first, though...


I am no expert, but I'm sure that violates thermodynamics. You would essentially be creating infinite energy from a finite source. To induce a current, you need a time varying magnetic field. A superconductor has a stable static field( I believe). You would either need to change the direction of the electrons or move the superconductor and copper coil relative to each other. Either way, you'd have to expend energy to do that, more than you'd produce for "free". Even if you didn't have that, the induced current in your copper would create back emf that would disrupt the electron flow in your super conductor and stop the whole works. Again, correct me if I am wrong, or if I've misinterpreted your comment.
Caliban
not rated yet Jul 09, 2010
@trek,

I could be wrong. Now, it shouldn't take long for someone to set the record straight...
Ashibayai
not rated yet Jul 09, 2010
Room temperature is a dream that is a ways off I think. Liquid Nitrogen temperature however could make this economical...
otto1923
not rated yet Jul 09, 2010
Store large quantities of energy until needed???? While I'm very far from an expert WRT super conductor properties but can they really be used to STORE large quantities of energy?
They may just be talking about 'energy storage flywheels' (motor/generator sets) -? Which they mentioned-
otto1923
not rated yet Jul 09, 2010
DamienS
3 / 5 (6) Jul 09, 2010
I don't really see much of an advance here at all. They've just removed short scale grain boundaries in an existing SC so that they don't impact on performance. Power transmission is still not viable (which requires huge lengths + cooling) and the bulk of the video is people playing with a levitating puck, just like twenty years ago!
xamien
not rated yet Jul 10, 2010
@trek - I don't think the example he was giving was supposed to be a perpetual motion reproduction of any sort, just meant to be a really efficient battery. The only problem, as you pointed out, is the interference from the copper on the superconductor's current. I can see some ideas that could be gotten from this to get around that problem but they all involve moving parts.
Jigga
3 / 5 (4) Jul 10, 2010
..the bulk of the video is people playing with a levitating puck, just like twenty years ago..
YBaCuO is a brittle ceramic, unsuitable for making of conductors, especially for power lines, where the main source of loss isn't resistivity, but corona, radiation and inductive loses. Transmission and distribution losses in the USA were estimated at 7.2% in 2003, the 1000 km of HVDC is having 3% power loss which means, only one third to half of power line loss can be attributed to ohmic loss. And the main criterion here is the reliability and safety of power transmission. From this perspective the current generation of superconductors has no chance for wider usage for power line transmission.
FredJose
1 / 5 (1) Jul 10, 2010
They may just be talking about 'energy storage flywheels' (motor/generator sets) -? Which they mentioned-

I think Parsec has it in the right ball-park. Storing a huge current in a superconducting coil is indeed the way things are done currently.
There isn't any motor or generator or any moving mechanical device involved, just the coil.
jimbo92107
3.3 / 5 (3) Jul 10, 2010
That was a strange, kind of aimless recitation of the basic principles of SC. "Breakthrough?" Not really. This is a good processing refinement, but a breakthrough would indicate some significant progress towards room temperature superconductors. I really wish the editors at Physorg would ease off on the casual hyperbole.
Roj
5 / 5 (1) Jul 10, 2010
Jigga wrote: the main source of loss isn't resistivity, but corona ..has no chance for wider usage for power line transmission.
Good point. Although, transmission voltage may drop below corona thresholds, with the coolant mechanics for liquid-nitrogen superconductors, the mass of this equipment requires ground-level installations.
Jigga
1 / 5 (2) Jul 10, 2010
"Breakthrough?" Not really. This is a good processing refinement

The same fallacy was used here: New computation method doesn't make a breakthrough in technology.

http://www.physor...488.html

..in a series of experiments, various elements, such as depleted uranium, were then added..

I'd call this "breakthrough" a blind alchemy, instead - despite the "secrets behind high temperature superconductors were revealed" already..

http://www.physor...523.html
gwrede
1 / 5 (2) Jul 10, 2010
Any reader of this article should do the following exercise: get hold of 20 year old tech news, and read maybe 50 articles. Then figure out how many of them you have ever heard of since.

Gives a totally new perspective on this article.
fmfbrestel
4.3 / 5 (3) Jul 10, 2010
Jeez guys what do you want, a panacea overnight? The reason why this advance is noteworthy is that the current capacity of SC is a major problem. Now sure, this article does not mention the scale of the current increase (which is an important fact left out), but any meaningful increase in SC current is nothing to scoff at. But what really sets this apart from most "breakthroughs" we read on this site, is that it is accompanied by a manufacturing cost decrease. So this isnt some 5% advance that cost 50% more to realize, instead it is a win-win advance. Is it instant room-temp SC as cheap as copper? -- no. Is it an important advance in SC technology? -- yes.
GaryB
not rated yet Jul 11, 2010
Store large quantities of energy until needed???? While I'm very far from an expert WRT super conductor properties but can they really be used to STORE large quantities of energy?
They may just be talking about 'energy storage flywheels' (motor/generator sets) -? Which they mentioned-


Let's see ... minus the cost to keep the nitrogen cool, which could be quite a large cost.
slaveunit
4.5 / 5 (2) Jul 11, 2010
The single most important benefit of reducing costs of making the 'high' temperature superconductors that we have currently available to us is energy storage. If the superconductors could be reduced in cost utility grade energy storage becomes a reality. Though we are not good at making superconductors we are good at making thermal insulators at least for fixed equipment a fixed plant with a solar powered liquid nitrogen facility suitably insulated would make a huge difference to renewable energy and would quite possibly be affordable. Energy storage is the ' killer app' for superconductors and is not out of reach.
gwrede
2 / 5 (2) Jul 11, 2010
Energy storage is the 'killer app' for superconductors and is not out of reach.


That was my very point. Ever since SC was invented, we were told 'hi-temp SC is just a decade away!' A little like AI always was. Or computers that understand speech.

In every generation there is a huge group of kids who decide up-front never to learn touch-typing 'because computers will understand speech by the time we grow up'. For the last 30 years I've heard the same story, and we're still at square one. Always a mere 10 years away. Tokamak, anyone?
fmfbrestel
5 / 5 (2) Jul 11, 2010
For the last 30 years I've heard the same story, and we're still at square one.


30 years ago the internet was still in its first trimester. Cell phones were the size of bricks and used 1g networks. The killer app running on the Apple II -- visicalc -- was sweaping across corporate america. The first generation of MRI machines were just exiting human trials. Microwave ovens were just taking off and cost at least $540 adjusted for inflation. Chrysler and Ford were just debuting airbags in their high end cars. 30 years ago YBCO wasnt even an idea in researchers minds. Lithium Ion batteries weren't even around until '95 and not really that good until well after the turn of the century.

If you think were still on square one, you are simply delusional.

Jigga
2.3 / 5 (3) Jul 12, 2010
If you think were still on square one, you are simply delusional
To put it more simply, scientists didn't make any progress, while ignoring important finding of J.F.Prins completely. They're not problem solving oriented, they're safe job oriented.

http://www.iop.or...8/3/319/

I wouldn't pay for such research, too. But I have to being tax payer.
otto1923
5 / 5 (1) Jul 13, 2010
@jigga
Everything at the proper Time. We can't allow economy-busting, paradigm-shifting, world-changing technologies to emerge at the wrong Time could we? That's what Jules Verne taught us, although it's just Common Sense.
Jigga
2 / 5 (4) Jul 13, 2010
We can't allow economy-busting, paradigm-shifting, world-changing technologies to emerge at the wrong Time could we?
We are supposed to face the wars and ecological disasters, after then. People never learn from their mistakes, until they exhaust all impossible ways.

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