This is a time of unprecedented opportunity for using neutrons in biological and soft matter research. The US Department of Energy (DOE) has invested in two forefront neutron user facilities, the accelerator-based Spallation Neutron Source (SNS) and the reactor-based High Flux Isotope Reactor (HFIR), at Oak Ridge National Laboratory (ORNL). Researchers have access to new instrumentation on some of the world’s most intense neutron beam lines for studying the structure, function, and dynamics of complex systems.
We anticipate that soft matter and biological sciences of tomorrow will require understanding, predicting, and manipulating complex systems to produce the new materials and products required to meet our nation’s future needs. Whether these complex systems are biological microorganisms or self-assembling scaffolds for mesoscale materials, they have properties that must be characterized across length and time scales using multidisciplinary approaches that exploit recent technological advances.
Neutron scattering techniques can probe enormous ranges of length and time scales, from angstroms to microns and from picoseconds to milliseconds. They are, therefore, ideal for studying multiscale phenomena intrinsic to biological and soft matter processes. With no charge, neutrons cause little radiation damage and are highly penetrating, enabling use of complex sample environments. Neutrons have energies similar to atomic motions, and their spin can be coupled to magnetic fields in spin echo measurements, allowing the study of dynamic processes over picosecond to microsecond time scales.
One of the most desirable properties of neutrons for biological and soft matter research is related to hydrogen (H). Photons and electrons interact with the atomic electric field. With just one electron, H is all but invisible to x-rays. Neutrons interact with nuclei, and H atoms have a relatively strong and negative scattering length, b. The isotope D has an even stronger b that is positive. These properties have provided precise information on a wide range of applications, from the location and dynamics of H atoms at the atomic level, to obtaining unique information on the concerted action of large, multidomain systems at longer length scales. We are committed to developing the technologies and tools, and to providing the expertise, to support biological and soft matter research using neutron scattering.