October 15
@
12:00 PM
–
1:00 PM
NEEP Seminar Series
Thursdays
12:00 – 1:00 PM
106 Engineering Research Building
Please contact office@neep.wisc.edu for assistance with remote participation.
Characterizing Defects and Disorder in Nuclear Materials with Spallation Neutron Probes
Materials utilized in nuclear applications must safely operate within harsh environments characterized by intense radiation, high temperatures with steep gradients, and changes in chemistry. Prolonged exposure to these extremes leads to material degradation that is ultimately driven by the formation of defects and disorder. This presentation summarizes recent efforts to use state-of-the-art analytical tools that have become recently available at large user facilities, such as the Spallation Neutron Source at Oak Ridge National Laboratory, to uniquely characterize nuclear materials. It will be shown that coupled X-ray and neutron total scattering experiments can provide unique insights into the local defect structure of fuel-type materials (e.g., UO2) and wasteform ceramics (e.g., A2B2O7 pyrochlore oxides). In almost all cases it was apparent that the formation of defects and disorder, and associated thermal recovery, is much more complex than previously though with distinct processes occurring over different length scales and sublattices in the material.
Maik Lang is a Professor and Pietro F. Pasqua Fellow in the Department of Nuclear Engineering at the University of Tennessee. He received his Ph.D. in physics from the University of Heidelberg (Germany) in 2004. He spent time as a postdoctoral researcher at the Helmholtz Center for Heavy Ion Research (Darmstadt, Germany) and at the University of Michigan (Ann Arbor, USA). In August of 2013, he joined the Department of Nuclear Engineering at the University of Tennessee as an Assistant Professor. Dr. Lang performs research in the field of disordered materials and investigates the behavior of materials under extreme environments, including energetic ion irradiation, high pressure and high temperature. He applies advanced materials characterization techniques that are available at user facilities, such as the Spallation Neutron Source at Oak Ridge National Laboratory. He is involved with several research projects funded by the U.S. Department of Energy.