U.S.-France Dissertation Enhancement: Variations in Dissociation Energies and Rates for Multiple NO2

University Of California-San Diego, La Jolla CA

Investigators

Abstract

0129286 Thiemens This two-year award for a dissertation enhancement program in atmospheric chemistry is part of a US-France collaboration between the University of California, San Diego, and research group at the University Joseph Fourier in Grenoble, France. Greg Michalski, a graduate student of Mark H. Thiemens, will carry out spectroscopic studies under the supervision of Remy Jost at the Physical Spectrometry Laboratory in Grenoble. The objectives of the collaboration are investigations of mass independent fractionation (MIF) mechanisms using spectroscopic analysis of NO2 isotopomers. The collaboration requires the synthesis of symmetric and asymmetric isotopomers of NO2. Mr. Michalski will carry out the spectroscopy on the isotopomers substituting the central nitrogen atom with isotopes with integer and half-nuclear spins. Probing states below the dissociation threshold will be done using Cavity Ringdown Spectroscopy. Mr. Michalski will also be trained to operate the French laser systems and the expansion jet using standard NO2. The US team brings to this collaboration expertise in isotopomer synthesis. This is complemented by French expertise in spectroscopic measurements. The resulting data will provide a basis for a complete and quantitative theory to explain MIF in planetary atmospheres, the geologic record and in meteorites. The collaboration contributes as well to research and education infrastructure. The graduate student will benefit through advanced training on specialized equipment in France and participation in an international team effort. This award represents the US side of parallel proposals to the NSF and the CNRS. NSF will cover travel funds and living expenses for the US graduate student. The CNRS will support visits by French researchers and students to the United States.