|
Powder
Diffractometer High Flux Isotope
Reactor (ORNL) |
Neutron scattering provides key information
on the positions, motions, and magnetic
properties of solids. When neutrons
flowing from a nuclear reactor bounce
off atoms in a sample, the neutrons
scatter in directions that depend
on the atoms' relative positions in
the sample structure. Changes in the
neutrons' velocity provide information
on the atoms' oscillations, or dynamics.
Since the late 1940s, the Office of
Science and predecessors have been
major supporters of neuron science,
including work by Clifford Shull and
Bertram Brockhouse, who shared the
1994 Nobel Prize in Physics for their
development of neutron scattering
techniques for studies of condensed
matter. Researchers at Oak Ridge,
Brookhaven, and Argonne national laboratories
developed neutron sources for spectroscopy,
scattering, and imaging experiments
and helped pioneer most of the associated
instruments and techniques. The Office
of Science currently supports three
neutron sourcesthe High-Flux
Isotope Reactor at Oak Ridge National
Laboratory, Intense Pulsed Neutron
Source at Argonne National Laboratory,
and Manuel Lujan Jr. Neutron Scattering
Facility at Los Alamos National Laboratoryused
by hundreds of researchers annually.
Under construction is a spallation
neutron source at Oak Ridge that will
be about an order of magnitude more
powerful than any existing pulsed
neutron source. Spallation produces
neutrons with little heat; pulsed
operation provides very high peak
intensities.
Scientific Impact:
Neutrons' unique properties, such
as sensitivity to light elements,
make them invaluable tools for polymer,
biological, and pharmaceutical sciences.
Studies made possible by neutron sources
and the associated techniques contribute
to the development of new materials,
such as ceramic superconductors.
Social Impact: Neutron
studies lead to new and improved products,
such as powerful magnets for highly
efficient electric motors. Also, because
their high penetrating power allows
nondestructive property measurements
deep within a specimen, neutrons have
been used to examine automotive gears
and brake discs, and defects in aircraft
wings, engines, and turbine blades.
Reference: Scientific
Research Facilities: A National Resource,
Office of Basic Energy Sciences, http://www.sc.doe.gov/production/bes/Brochures.htm
URL: http://neutrons.ornl.gov/
http://www.sns.gov/
http://www.pns.anl.gov
http://lansce.lanl.gov/index_ext.htm
Technical Contact:
Don Freeburn, Office of Basic Energy
Sciences, 301-903-3156
Press Contact: Jeff
Sherwood, DOE Office of Public Affairs,
202-586-5806
SC-Funding Office:
Office of Basic Energy Sciences |