With stronger dipole magnets, an accelerator can push particles
to much higher energies around the same-sized circular beam
path. Toward that end, scientists and engineers here have
new magnet with a world record field-strength of 14.7
Tesla. The magnetic forces are enormous, about 3 million
pounds, or more than the combined thrust of a dozen 747
planes. The magnet is 300,000 times as strong as the Earth's
computer read heads and storage devices have depended upon a phenomenon
known as Giant Magnetoresistance since the late 1980s, but in 1993 an
even more spectacular effect was discovered that can increase or decrease
resistance to an electric current by several orders of magnitude. No one
knows how or why it works, but scientists using the Advanced Light Source
are beginning to close in on the secrets of "Colossal"
a beam of synchrotron x rays is focused on a sample, the
material emits electrons. Photoemission electron microscopes
(PEEMs) collect and focus these electrons, producing an
image that not only gives a physical picture of the sample
but can indicate what it's made of and how its atoms and
molecules are organized. PEEM2 is a microscope able to
resolve features separated by just billionths of a meter
-- ten times better than the best optical microscopes.
Because the structures of many complex materials are even
teams now are racing to build a third generation PEEM.