and superconducting magnets, while not in use in everyday homes
and work places because of their need for low temperature refrigeration,
are widely used in particle accelerators, and medical imaging devices.
Figure 5 shows a medical MRI (Magnetic Resonance Imaging) unit that
uses a large superconducting magnet to image the interior parts
of the human body to very fine detail. Thousands of these superconducting
MRI units are already in use around the World.
Also in use are many miles of superconducting magnets for high
energy particle accelerators employed for physics research into
the structure of matter. The existing superconductors in these accelerator
magnets, if they had been used for maglev, would provide the magnets
for thousands of vehicles - enough to carry a large fraction of
US intercity passenger and truck traffic.
In addition to maglev, other applications of superconductivity
are also developing rapidly, including lossless underground transmission
lines, windings for large motors and generators and superconducting
energy storage. Such devices will become major users of superconductors
in the coming decades.