WED October 7
Wednesday, October 7 am- Workshops
Science’s conception of the atomic scale structure of crystalline materials derives from the Bragg peaks in X-ray diffraction and their obligatory origin in the periodic crystal lattice. But if Bragg had had access to synchrotron radiation and its associated local structure methods we would view materials quite differently. Although periodicity has been infiinitely useful in understanding the properties of matter, it is also quite limiting in that almost all materials of technological and scientific interest contain impurities or other defects in their crystal structures, sometimes inadvertent or as the consequence of aging but just as often deliberately introduced, that determine their behaviors and utility. Since these break the periodicity and symmetry their signatures in crystallography are often small and ambiguous and conventional refinement methods give results that can be removed from reality. Elucidating structure:funciton relationships - in complex structural materials, electronic and correlated materials, catalysts, and even environmental and forensic samples - therefore requires complete structure determination that includes complementary crystallography that determines the long range average structure of the periodic portion of the material and local structure methods, e.g., XAFS and pair distribution funciton analysis, that are sensitive to local order. Other methods can also be essential, e.g., microscopy that reveals unexpected interactions and “chemistry” between separate phases. In addition, these x-ray techniques also provide information on dynamical aspects of the structure via their inelastic or instantaneous methods that are complementary to elastic and inelastic neutron scattering. The missing idea that necessitates this range of experimental measurements is strong interactions, i.e., collective and cooperative behavior, between these “defects” or inhomogeneities that can cause them to cluster or self organize in other ways, especially in non-equilibrium systems.
This workshop is an introduction to the infrastructure, tools and algorithms used by the LCLS-II data system in TMO, RIX, and TXI. Because it is too costly at 1 MHz repetition rate to persist the full raw LCLS-II data volume to disk, the data size will be reduced in real-time by ~10x. To ensure that the physics is not affected by this, coordination between LCLS Users and the Data Systems group will be necessary. This workshop will discuss the data acquisition, data management, and analysis systems for LCLS-II, describe the status of the effort, and solicit input for improvements.
The area of quantum materials is fundamental to our understanding of matter and promises incredible impact in the form of new technologies. With the commencement of the LCLS-II imminent, the ability to harness coherent, short pulsed x-rays with 4 orders of magnitude more photons will usher in a new era of science. The field of quantum materials is fertile ground for novel ideas and new capabilities that will be initiated with this revolutionary tool. This workshop will bring together international experts in quantum materials research, with a specific focus on the study of low-energy excitations, using ultrafast spectroscopy and other tools to pave the way for future developments and collaborations in this important area.