Neutron Science at ORNL

Neutron Science at ORNL

The Neutron Sciences Directorate (NScD) manages and operates the Spallation Neutron Source and the High Flux Isotope Reactor, two of the world's most advanced neutron scattering facilities.

Both facilities are funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.

In conjunction with the University of Tennessee, NScD also operates the Shull Wollan Center — a Joint Institute for Neutron Sciences.

The goal of NScD is achieving excellence in science. Through safe, reliable operation and continual development, we strive to provide researchers with unmatched capabilities for understanding the structure and properties of materials, macromolecular and biological systems, and the fundamental physics of the neutron.

Neutron Scattering Science

Neutrons are one of the fundamental particles that make up matter and have properties that make them ideal for certain types of research. In the universe, neutrons are abundant, making up more than half of all visible matter.

Neutron scattering provides information about the positions, motions, and magnetic properties of solids. When a beam of neutrons is aimed at a sample, many neutrons will pass through the material. But some will interact directly with atomic nuclei and "bounce" away at an angle, like colliding balls in a game of pool. This behavior is called neutron diffraction, or neutron scattering.

Using detectors, scientists can count scattered neutrons, measure their energies and the angles at which they scatter, and map their final position (shown as a diffraction pattern of dots with varying intensities). In this way, scientists can glean details about the nature of materials ranging from liquid crystals to superconducting ceramics, from proteins to plastics, and from metals to micelles to metallic glass magnets.

How Can Neutrons Be Used for Research?

Neutrons have many properties that make them ideal for certain types of research. Because of their unique sensitivity to hydrogen, neutrons can be used to precisely locate hydrogen atoms, enabling a more accurate determination of molecular structure, which is important for the design of new therapeutic drugs. Neutrons scattered from hydrogen in water can locate bits of moisture in fighter jet wings—signs of microscopic cracking and early corrosion that pinpoint the part of the wing that should be replaced.

Besides hydrogen, neutrons can locate other light atoms among heavy atoms. This capability is helping scientists to open the field of quantum superstates, such as superconductivity and superfluidity. Researchers are making measurements of the atomic momentum distribution of liquid 4He and are looking for a 4He supersolid state. They have determined the critical positions of light oxygen atoms in promising high-temperature, superconducting materials.

Because the energies of thermal neutrons almost match the energies of atoms in motion, neutrons can be used to track molecular vibrations and movements of atoms of a protein during catalytic reactions. Recent studies with neutrons have revealed the earliest structural formation of the disease type of the protein Huntingtin's, and that research is moving forward to study protein malformation responsible for Alzheimer's and Parkinson's diseases.

Key Contacts

Associate Laboratory Director Paul Langan
Chief Scientist Alan Tennant
Shull Wollan Center Director Alan Tennant
Biology and Soft Matter Division Director Wim Bras
Chemical and Engineering Materials Division Director Richard Ibberson
Instrument and Source Division Director Don Abercrombie
Neutron Data Analysis and Visualization Division Director Thomas Proffen
Quantum Condensed Matter Division Director Stephen Nagler
Research Accelerator Division Director Fulvia Pilat
Research Reactors Division Director Tim Powers
Scientific and Program Services Office Director Crystal Schrof
Directorate Operations Manager Hans Vogel
Communications and Outreach Kelley Smith