Uses of Superconductors

Efficient Electricity Transportation

Superconductors have many uses - the most obvious being as very efficient conductors; if the national grid were made of superconductors rather than aluminium, then the savings would be enormous - there would be no need to transform the electricity to a higher voltage (this lowers the current, which reduces energy loss to heat) and then back down again.
Superconducting magnets are also more efficient in generating electricity than conventional copper wire generators - in fact, a superconducting generator about half the size of a copper wire generator is about 99% efficient; typical generators are around 50% efficient.

The US Department of Energy are actively encourages the use of superconductors as energy efficient devices.
At the moment, the problem lies with the critical temperature - unless a material is found that can superconduct above 300K, some sort of cooling system needs to be employed, which would be expensive, although companies are developing prototypes - in December 1998, Pirelli Wire built a test 150ft cable that transmitted electricity using high temperature superconducting materials.

Magnetic Levitation

Above: The Yamanashi MLX01 MagLev test vehicle achieved a speed of 343 miles per hour on April 14, 1999.

So-called 'MagLev' trains such as the Yamanashi MLX01 train show above have been under development in Japan for the past two decades - the train floats above the track using superconducting magnets; this eliminates friction and energy loss as heat, allowing the train to reach such high speeds.

Visit the MagLev R&D Department Home Page to find out more about the project.

Magnetic Resonance Imaging (MRI)

Above: MRI scan of a human skull

MRI is a technique developed in the 1940s that allows doctors to see what is happening inside the body without directly performing surgery. The development of superconductors has improved the field of MRI as the superconducting magnet can be smaller and more efficient than an equivalent conventional magnet.
Check out the University of Texas Austin's NMRI Lab for more information and links.

Synchrotrons and Cyclotrons (Particle Colliders)

Particle Colliders like CERN's Large Hadron Collider (LHC) are like very large running tracks that are used to accelerate particles (i.e. eletrons, positrons, hadrons and more) to speeds approaching the speed of light before they are collided with one another or other atoms, usually to split them (this was how many sub-nuclear particles such as taus and neutrinos were discovered).
They do this by cycling the particle using magnetic fields, continually increasing the speed of the particle.
The first project to use superconducting magnets was the proton-antiproton collider at Fermilab.

Fast Electronic Switches

Type II superconductors can be used to as very fast electronic switches (as they have no moving parts), due to the way in which a magnetic field can penetrate into the superconductor - this has allowed Japanese researchers to build a 4-bit computer microchip (compared to today's 32-bit and 64-bit processors) operating at about 500 times the speed of current processors, where heat output is currently a major problem with typical speeds approaching the 1GHz mark.
An article in Superconductor Week focuses upon the efforts of NASA, DARPA and others to build a 'petaflop' (a thousand-trillion floating point operations per second - compared to today's 'teraflop' (1 trillion Flops per sec) computers) computer using superconductor technology.

Finding Out More...

The US Department of Energy's Superconductivity page and Superconductors.org's 'Uses' section are useful pages for information and links about the applications of superconductors (or for borrowing pictures...).