Student: Allison Savage (Univ. Iowa)

Mentor: Oliver Tschauner

Spatially Resolved Optical Spectrometry and Single Crystal Diffraction of Radiation-Damaged Materials

A major goal of developing a storage medium for radioactive waste is the identification of chemically suitable and durable material for storage in repositories. Radiation damage induces enhanced chemical diffusion and structural breakdown of the host materials, which can lead to contamination of the surrounding environment. During this project four different naturally occurring materials which are common carriers of thorium and uranium were examined: gadolite, perrierite, allanite, and pyrochlore. The first three are silicates and while the last is an oxide.Their spectra and absorption bands were examined to identify prominent features due to radiation damage. Pyrochlore was examined by x-ray diffraction at the Advanced Photon Source at Argonne National Laboratory. The spectra for all four samples were dominated by the Fe²⁺ and Fe³⁺charge transfer band. The optical absorption spectra do not have any defining characteristic features of radiation damage.