Development of a Small Angle X-ray Scattering Station for Dynamical Materials Studies and Education

Cornell University, Ithaca NY

Investigators

Abstract

This grant provides support for the development of a small angle X-ray scattering station (SAXS) for dynamical materials studies and education at the Cornell High Energy Synchrotron Source (CHESS). This X-ray station will be a user facility to study the structure and dynamics of materials with feature sizes ranging from 0.1 to 200 nanometers and time scales ranging from sub-millisecond to indefinite. The types of materials that will be explored include polymers, nano-scale composites, macro-surfactants, dendrimers and organic-inorganic hybrid thin films. This facility will take advantage of the extremely high-flux X-ray beams produced by the "G" wiggler beamline at CHESS. Designed from the start to deliver stable, focussed, high intensity X-ray beams, the G-line facility will routinely deliver a high flux of more than 1015 photons per second onto a specimen. With such high fluxes it is becoming practical to perform, on times as short as milliseconds to microseconds, routine in-situ measurements of particle size, shape, lattice distortions, strain and relaxation, molecular reorientations, and complete phase transformations. With the extremely powerful X-ray beams from the wiggler source at CHESS, this new facility will significantly increase national capabilities to collect high quality X-ray data from weak scattering and rapidly varying materials. The classes of materials to be studied - surfactants, dendrimers, polymers, proteins and thin-films - fall into the broad class of "soft matter" that has traditionally been difficult to study. This new SAXS facility is being built on the central campus of Cornell University, providing a rare opportunity for undergraduate and graduate students to have long-term participation and projects at a national synchrotron center. Graduate students are expected to help design and build the facility as well as carry out their own dissertation projects. This overall 'hands-on' approach will give a broad group of students a deep understanding of X-ray techniques and provide a thorough training of scientists for future materials research careers.