Todd Major

Measurement of fundamental physical constants of molecules via laser-based vibrational spectroscopy

A fundamental understanding of chemical reactions requires a detailed knowledge of energy transfer during molecular collisions.  Like measuring blood pressure in order to determine heart health, measuring the pressure broadening coefficient for a gas immersed in a collision gas furthers the understanding of the energy transfer between two molecules.  The goal of this research is to develop a diode-laser-based technique to measure the pressure broadening coefficient.  The measurement of the pressure broadening coefficient requires a non-linear least squares fit of a complicated function. In order to facilitate the fit, experimental techniques were developed to estimate parameters that can not be directly measured.  Under normal circumstances, the pressure broadening coefficient of carbon dioxide in air can be obtained successfully.  We have measured a pressure broadening coefficient of carbon dioxide in air of 0.094 +/- 0.003 wavenumbers/atm.  The literature value is 0.0952 wavenumbers/atm, according to the HITRAN database [1].  We are currently exploring the reproducibly of our measurement.

Faculty Mentor: Stephanie Schaertel, Chemistry

Page last modified July 29, 2009