Shawn Kathmann, Ph.D.
Senior Research Scientist, Fundamental and Computational Sciences Directorate, Chemical and Material Sciences Division, Molecular Interactions and TransformationsCurrent Activities and Projects
Vapor to liquid nucleation is a dynamical rare event process governed by a delicate interplay between condensation and evaporation rates. Since the vapor is comprised essentially of monomers the formation of clusters is governed by monomer association and dissociation reactions. The formation of a cluster is impeded by a free energy of activation which, since no potential energy barrier exists, is entropic in nature. Variational transition state theory provides a framework in which equilibrium evaporation rate constants can be calculated and the corresponding condensation rates determined from a theory of the vapor and detailed balance. The nucleation rate can then be obtained by solving the psuedo-first order kinetic equations.
Research Interests
Atmospheric chemistry, nucleation phenomena, effects of system size on the themodynamic quantites relevent to the atmosphere, anything which has fundamental physical significance.
Past Experience
Monte Carlo Simulation of Small Sulfuric Acid-Water Clusters
Education
B.S. in Physics from Illinois State University (1991)
Ph.D in Physics from University of Missouri-Rolla (1998)
Awards, Honors, & Appointments
Undergraduate:
Teaching Assistant (1year)
Reseach Assistant (3 years)
Research: Classical Dynamics of Proton Motion in an X-Type Magnetic Field
Award for Excellence in Physics (1990)
Graduate:
Teaching Assistant (1 semester)
Research Assistant (5 years)
Research: Studies of small molecular clusters
Physics Instructor (1semester)
Laird Schearer Physics Award (1996)
