Department of Chemistry
A headshot

Simon North
John W. Bevan Professor in Chemistry
Head, Department of Chemistry

Department of Chemistry
Texas A&M University
College Station, TX 77843-3255

P: 979-845-4947
F: 979-845-2971

Researcher ID

Current Activities

Our research involves trying to understand chemical reactivity on a microscopic quantum-state resolved level. We focus on isolated molecules in the gas-phase to develop a detailed description of the factors which influence the rates, energy disposal, and final products in a reaction. In order to address these issues we use lasers to carefully control the preparation of excited molecules and to probe all the properties of the reaction products. chemical reactivity on a microscopic quantum-state resolved levelOur specific interests include understanding atmospheric photochemistry, the tropospheric oxidation of biogenic hydrocarbons, and laser diagnostic development for flow field characterization. The laboratory contains equipment to perform state-of-the-art experiments in chemical dynamics and kinetics and is associated with several interdisciplinary University Research Centers. Our photochemistry experiments combine molecular beam and state-resolved ionization techniques with position-sensitive ion imaging to determine the identity and energy content of photochemical products in the absence of secondary collisions. Studies focus on the photodissociation of jet-cooled radicals of atmospheric relevance and preliminary results have already stimulated collaboration with several theoretical groups. The experiments provide a stringent test for modern theory and allow assessment of the impact that the photochemistry has on atmospheric modeling.

Our group is also interested in understanding tropospheric chemistry. One effort involves the study of the oxidation of tropospheric biogenic hydrocarbons which has major implications for local and regional air quality. In recent years it has become increasing evident that refining our understanding of atmospheric chemistry of hydrocarbons requires detailed characterization of the elementary reaction mechanism that must involve combined experimental and theoretical studies. Our approach is based on this philosophy, combining state-of-the-art experimental techniques, chemical ionization mass spectrometry and laser photolysis/laser induced fluorescence, with modern ab initio and rates theory calculations to obtain a comprehensive and predictive description of hydrocarbon oxidation chemistry. Ultimately our goal is to predict ozone formation on the regional and global scales as well as the long-range transport of NOx. Recently we have extended our atmospheric studies to include the development and application of field instrumentation for measuring trace radical species.

Finally, our group is involved in collaborative efforts with Rodney Bowersox (Aerospace Engineering) and the National Aerothermochemistry Laboratory at Texas A&M University. We are currently developing novel laser diagnostics for velocity and basic state characterization in hypersonic flows. This research focuses on optical characterization of high speed (hypersonic) flows; measurement of freestream turbulence, measurement of internal energy distributions and relaxation of non-thermal equilibrium (NTE) distributions, surface ablation and reactivity, and laser induced NTE driven turbulence. These measurements require the application of state-of-the art laser diagnostic techniques such as coherent anti-Stokes Raman spectroscopy (CARS), Raman, and two-line planar laser induced fluorescence (PLIF).

Educational Background

B. S., 1990, University of New Hampshire

Ph. D., 1995, University of California at Berkeley

Postdoctoral Fellow, 1995-1997, Brookhaven National Laboratory

Awards & Recognition

  • College-level Association of Former Students Faculty Distinguished Achievement Award in Teaching (2010)
  • Co-Director, National Aerothermochemistry Laboratory
  • University Level Association of Former Students Faculty Distinguished Achievement Award in Teaching (2009)
  • College-level Association of Former Students Faculty Distinguished Achievement Award in Teaching (2004)
  • Associate Director, Center for Atmospheric Chemistry and the Environment

Selected Publications

  • C. E. Gunthardt, C. J. Wallace, G. E. Hall, R. W. Field, and S. W. North: "Anomalous Intensities in the 2+1 REMPI Spectrum of the E 1Π - X 1Σ Transition of CO", Journal of Chemical Physics, 123, 2780-2788 (2019). DOI: 10.1021/acs.jpca.9b00109
  • C. J. Wallace, C. E. Gunthardt, G. C. McBane, and S. W. North: "Empirical assignment of absorbing electronic state contributions to OCS photodissociation product state populations from 214 to 248 nm" Chem. Phys. 520, 1 (2019).
  • J. D. Winner, N. A. West, M. H. McIlvoy, Z. D. Buen, R. D. W. Bowersox, and S. W. North: "The role of near resonance electronic energy transfer on the collisional quenching of NO (A 2Σ+) by C6H6 and C6F6 at low temperature" Chem. Phys., 501, 86 (2018).
  • M. L. Warter, C. E. Gunthardt, W. Wei, G. C. McBane, and S. W. North: "Nascent O2 (a 1Δg, v = 0, 1) Rotational Distributions from the Photodissociation of Jet-Cooled O3 in the Hartley Band", Journal of Chemical Physics, 149, 134309 (2018). DOI: 10.1063/1.5051540
  • W. Wei, C. J. Wallace, M. P. Grubb, and S. W. North: "A Method of Extracting Speed-Dependent Vector Correlations from 2+1 REMPI Ion Images" Journal of Chemical Physics, 147, 013947 (2017). DOI: 10.1063/1.4985704