Quasi Elastic-Neutron Scattering | NNSS 2025 скачать в хорошем качестве

Quasi Elastic-Neutron Scattering | NNSS 2025

Quasi-Elastic Neutron Scattering Presented by Niina Jalarvo 1st National Neutron Scattering School, 2025 Oak Ridge National Laboratory (ORNL) In this lecture, Niina Jalarvo introduces quasi-elastic neutron scattering (QENS) as a technique for probing atomic and molecular motion on picosecond to nanosecond timescales. The presentation explains how QENS measurements capture small energy broadenings around the elastic line that arise from diffusive and relaxational dynamics in materials. Jalarvo outlines the theoretical framework of quasi-elastic scattering, including the relationship between energy linewidth, momentum transfer, and characteristic timescales of motion. The lecture discusses common models used to interpret QENS data, such as jump diffusion and confined diffusion, and describes how experimental parameters and instrument resolution influence measurable dynamics. By revealing translational and rotational motion in liquids, polymers, soft matter, and biological systems, quasi-elastic neutron scattering provides insight into diffusion mechanisms and microscopic transport processes. The session emphasizes how QENS complements other spectroscopic and structural techniques by directly quantifying dynamics at the atomic scale. Learn more about neutron science at ORNL: https://neutrons.ornl.gov Learn about the National Neutron Scattering School at ORNL: https://neutrons.ornl.gov/nns