PUPSS Seminar: Marcella Berg
Fri. Mar. 3 12:30 PM
- Fri. Mar. 3 01:20 PM
Location: In Person 3M69 & via Zoom
Prairie Universities Physics Speaker Series: Marcella Berg
Assistant Professor, Department of Physics, University of Regina
"Neutrons for Materials Research"
Neutrons are subatomic particles with no net electric charge, which means that they generally can penetrate deeper into matter than other subatomic particles. The interaction between neutrons and matter can be used to gather information about bulk characteristics of materials by evaluating the scattered neutrons. This opens a whole assortment of possible physics knowledge that can be acquired from studying neutron-matter interactions. Neutron scattering is versatile and is used both for studying structures as well as dynamics on different lengths and time scales. This technique can be applied to a variety of materials but is particularly well suited for studying lighter elements such as hydrogen-rich materials.
The neutron scattering response can be inelastic, quasi-elastic, or elastic depending on the finite energy transfer between the neutrons and the material. The inelastic signal can probe the periodic motions of the molecules in the sample with a finite energy transfer, while the elastic signal is suitable for acquiring structural information. The Quasi-elastic neutron scattering is well suited to gather quantitative information about the correlation times and length scales of the diffuse motion occurring in hydrogenous materials in different geometries.
This talk will present the application of neutron scattering on biomass and how it is used to understand the fundamental molecular processes that drive biomass deconstruction. Furthermore, the same samples were also modeled computationally using molecular dynamics simulations, where both the composition and densities of the experimental measurements are considered. Molecular dynamics simulations probes similar length- and timescale as neutron scattering experiments, so the scattering functions can be calculated from the atomic positions in simulation trajectories and compared directly.