LDRD Seminar Series: ‘Faster Fluctuations and More Exact Interfaces: Advancing Capabilities for the APS Upgrade’
Argonne Physicist Alec Sandy, group leader of the APS X-Ray Science Division’s Time-Resolved Research Group, will discuss his Laboratory-Directed Research and Development (LDRD) sponsored work at the LDRD Seminar Series presentation Tuesday, Oct. 25, 2016.
“Faster Fluctuations and More Exact Interfaces: Advancing Capabilities for the APS Upgrade” will begin at 12:30 p.m. in the Bldg. 203 Auditorium. All are welcome to attend.
The Advanced Photon Source is proposing a large-scale upgrade (APS-U) in the early 2020s. It will dramatically improve capabilities for high-energy X-ray scattering, nano-resolved probes of the structure and identity of materials, and techniques that use coherence to determine the exact structure of materials, or to obtain statistical information about spontaneous changes in these materials. Using the properties of today’s APS, Sandy’s LDRD seminar focuses on advancing capabilities in two areas that will flourish using the 100-fold increase in coherent X-ray flux that APS-U will provide.
The first area is advancing time correlation X-ray techniques to provide markedly improved sensitivity to fluctuations in condensed matter. By collaborating with scientists at Argonne and elsewhere in the U.S. and the world, the team has driven the development and application of increasingly powerful X-ray area detectors for measuring structure and dynamics in colloidal suspensions. Their work has resulted in measurements with 50X greater time sensitivity than previous APS measurements and provides nanoscale insight into how materials gel.
The second area is determining the exact three-dimensional structure of materials at or near interfaces. The team has worked with scientists from other synchrotron X-ray sources to prepare, measure and reconstruct model mesoscale surface patterns of increasing complexity by using successively more coherent X-rays. Their results demonstrate the feasibility of such measurements and show that such work will blossom with APS-U.
For the past 13 years, Alec Sandy has been a beamline scientist at the Advanced Photon Source (APS) and, more recently, the group leader for the APS X-Ray Science Division’s Time-Resolved Research Group. Prior to that, he worked with outside partners to build one of the early beamlines at the APS. Sandy’s research interests are primarily focused on developing and applying time-resolved coherent-X-ray-scattering techniques, so-called XPCS, to understand the spontaneous nanoscale fluctuations of condensed matter at or evolving to equilibrium.