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| Future Applications |
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-> Superconductors
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| Superconductors |
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Superconductors are a technology of the future,
and copper is playing an important role in this advanced technology.
Superconductors are materials that carry large quantities of electricity
with zero electrical resistance when cooled to very low (cryogenic)
temperatures. The economic implications of zero electrical resistance
are profound: superior transmission cable, more compact generators,
and more powerful motors, to name just a few. Superconductors will
someday be especially important to the power industry. End users of
electricity will also benefit from superconductors.
While superconductors have been known for decades (experiments on
zero resistivity of mercury at 4.20°K were conducted way back in 1911),
the only commercial application until recently was in medical magnetic
resonance imaging devices which utilized low-temperature superconductor
(LTS) wires.
But in 1986, scientists discovered a new family of superconductor
materials that operate at 5-20 times higher temperatures than the
low-temperature superconductor (LTS) materials that were known for
decades. The new materials, which are ceramic compounds, have become
known as high-temperature superconductors (HTS). The most promising
HTS materials to date are copper-oxygen compounds called "cuprates."
In 1986, scientists observed superconductivity at 300°K in an oxide
material that contained copper, lanthanum, strontium, and barium.
The following year, a YBaCu3O7 material was created that pushed superconductivity
properties up to 90°K.
Today, there are more than 100 superconducting compounds, most of
which exhibit configurations of copper and oxygen ions (i.e., the
cuprate system).
The lower cost of cooling cuprate HTS materials has enhanced the commercial
viability of superconductor applications and has created the possibility
of using high power density superconducting wires in such energy-intensive
applications as power transmission cables, motors, and generators.
Commercial development is currently being focused on long-length conductors
(wires) and thin films for electronic applications.
Copper Wire in Superconducting Magnets. In addition to copper's role
as an HTS material, copper wire has also found a home with superconducting
electromagnetics. In fact, nearly 45 tonnes (50 tons) of high conductivity,
oxygen-free copper wire was used to make 1700 superconducting electromagnetics
for a collider at the US Department of Energy's Brookhaven National
Laboratory in New York. |
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