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High-Temp Superconducting Tape
DrLudicrous writes "The NYTimes is running a little overview of the current state of mass produced superconducting materials. A company named Superpower (another blurb on them here) is making a layered superconducting tape out of ceramic materials- ceramics that are high-temperature superconductors (no resistance at liquid nitrogen temperatures, 77K). This is much cheaper to maintain than technologies based on superconducting metals, which tend to require liquid helium (~4 Kelvin) temperatures. A note of contention: the article mentions that superconductivity is not well understood -- high-temperature superconductors are not, but classical 'low-temperature' superconductors are well-described under the Bardeen-Cooper-Schrieffer (BCS) theory."
Search for MgB2 , though it is not much better (except possibly for digital apps where HTS sucked big time...)
And I actually used to work in SCE...
Paul B.
Pardon, but wtf are you talking about?
...except possibly for digital apps where HTS sucked big time
Search for MgB2...
Yes....and...? MgB2 is a standard low temp. superconductor with a Tc of only ~40 Kelvin.
Whaaa? HTS (high temp. superconductors) are perfectly suited to "digital apps" in many situations. A company called STI makes HT superconducting filters for cell phone antennas in order to increase data bandwidth and and decrease service dropout by making their recievers more sensitive. And Josephson Junctions make up some of the fastest digital IC's in existance at many hundreds of gigahertz.
And I actually used to work in SCE...
Am I the only one who has no idea what this is?
- "Hear that?! The percolations are imminent! Cease your ingress!"
It's worth noting that there are no theories (so far as I've heard anyway) that expressly forbid superconductivity at room temperature. The BCS theory of conventional superconductors forbids Tc's beyond about ~50K if I recall correctly, but high temp. superconductors don't follow BCS and have much higher Tc's, who knows if there's another class of electron superconductors with even higher Tc's. In fact it is thought that certain parts of the insides of neutron stars have superconducting protons floating around in a sea of superfluid neutrons at many millions of Kelvin!!
- "Hear that?! The percolations are imminent! Cease your ingress!"
Actually, magnesium diboride is much easier to work with than the HTSCs. It doesn't have the grain boundary problems that bedevil the latter. Even better, its normal state conductivity at low temperature is close to that of copper (and something like 20 times that of niobium-tin), making the material much more resistant to damage during quenches.
but we're not going to be making power lines
Thankfully there are others who aren't as paranoid as you are about physics we don't quite understand theoretically, but do understand phenomenologically, as we already have power lines made out of this stuff.
Here are several press releases about it: Copenhagen, Chicago, and Detroit already are laying high-Tc superconducting cable. They're already in use at Copenhagen. And that was in 2001.
The mass and resistive loss savings by going to superconductors can easily pay for the excess cooling equipment and cost, if the scale is right. And when you're talking about kilo-amperes, that scale is right.
MgB2 is a standard low temp. superconductor with a Tc of only ~40 Kelvin.
:-)
;-)
As pfdietz pointed out below, MgB2 is so much easier to work with than HTS ceramics. Its discovery is considered the next big thing in the field since the discovery of high-temperature superconductivity, not because of increased Tc, but because it can be deposited using standard semiconductor tools and one does not have to worry about grain size/orientation/etc.
Whaaa? HTS (high temp. superconductors) are perfectly suited to "digital apps" in many situations. A company called STI makes HT superconducting filters for cell phone antennas in order to increase data bandwidth and and decrease service dropout by making their recievers more sensitive.
STI/Conductus filters are purely passive devices, there is not a single Josephson junction nor a single cold logic gate. As a matter of fact filters themselves are rather simple, their main achievement is development and mass-production of relatively low cost and reliable cryocoolers. And of course they are not used in "cell phone antennas", rather in "cell phone *base station* antennas", big difference!
But when I was talking about "digital" I meant exactly the stuff from your second link. Search for a guy named Paul Bunyk there , look at my user ID and then decided if I have something to say about those matters...
Am I the only one who has no idea what this is? SuperConductor Electronics.
Paul B.