Argonne National Laboratory

Upcoming Events

Data-Driven 4-D X-Ray Imaging of Nanoscale Dynamics

NST Seminar
Mathew J. Cherukara (XSD)
April 20, 2018 11:00AM to 12:00PM
Building 440, Room A105-106

Abstract: Observing the dynamic behavior of materials following ultrafast excitation can reveal insights into the response of materials under nonequilibrium conditions of pressure, temperature, and deformation. Such insights into materials response under nonequilibrium is essential for designing novel materials for catalysis, low-dimensional heat management, piezoelectrics, and other energy applications. However, materials response under such conditions is challenging to characterize, especially at the nano to mesoscopic spatiotemporal scales.

Time-resolved coherent diffraction imaging (CDI) is a unique technique that enables three-dimensional (3-D) imaging of lattice structure and strain on sub-nanosecond time scales. In such a "pump-probe" technique, stroboscopic X-ray "probes" are used to image the transient response of a sample following its excitation by a laser "pump."

In this talk, I will present our recent work in imaging and modeling phonon transport and lattice dynamics in nanomaterials. I will also describe my work in the use of deep neural networks in accelerating the analysis of and increasing the robustness of image recovery from 3-D X-ray diffraction data. Once trained, our deep neural networks are thousands of times faster than traditional phase retrieval algorithms used for image reconstruction from 3-D diffraction data.