ELSI

Research & Activities

ELSI Seminar

Stable Isotopes and mass Independent Chemistry to resolve the Origin and Evolution of the Solar System and earth

Speaker
Mark Thiemens
Date
July 8, 2016
Time
15:30
Room

ELSI-1 Building - 102 ELSI Hall

It has been known for more than 40 years that the oxygen isotopic composition of meteorites has an anomalous and mass independent isotopic composition. To this day, the source of these anomalies are not agreed upon, though it is clear that a chemical process must be involved.

There are numerous theories and models in the literature that have been published to account for the observed meteoritic anomalies in oxygen, as well as sulfur and nitrogen. There are however very few experiments that have been done to actually test any model, photochemical or non-photochemical. The processes of dissociation and molecular reactions are both likely processes to be of influence. Our lab has studied both and made progress in examining the reactions that were the most important at the very formation step that converts a gas to a solid. The experiments are of notable difficulty because of the need for high temperature and controlled reaction of oxidation of metal oxides to higher order molecules. Photochemical processes, especially of sulfur an oxygen are difficult because every short UV wavelengths are needed and sophisticated light sources such as a synchrotron are required. This talk examines the up to date experimental results in this capacity.