The Millimeter- and Submillimeter-Wave Spectroscopy of Low Temperature Collisions

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

Professors Frank DeLucia and Eric Herbst of the University of Ohio State University are funded by the Experimental Physical Chemistry program to perform experimental and theoretical studies of low energy molecular collisions. The goal is to understand the dynamics, spectroscopy and interactions which govern the behavior of low temperature (10K) collisions of small species such as helium, hydrogen, formaldehyde and carbon monoxide. Under the experimental conditions here, the collision energies are less than the binding energies of the van der Waals complex between the collision partners. (The well depths typically correspond to temperatures of less than a few tens of degrees). Along with providing data on collisions of this type, the PIs will develop new experimental techniques such as state-to-state inelastic rotational energy transfer, collisional cooling methods and new molecular ion production methods. In particular, they will attempt a molecular beam maser scheme which should allow them to overcome some previously encountered thermal averaging problems. Some ab initio calculations will be performed that will aid in the data interpretation. A successful outcome of this work will be highly accurate potentials describing interactions between ultracold molecules that will serve as benchmarks for quantum theory. These fundamental studies relate to the interconnected areas of quantum chemistry and scattering theory, and our understanding of chemical processes and energy transfer in the interstellar medium. The work will also provide spectroscopic data of use for interpreting observations of astrophysical and atmospheric species.