Time-Resolved IR Spectroscopy, Energy Transfer, and State-To-State Collision Dynamics of Atmospheric Species
Abstract
Achievements under the AFOSR grant have been in the following areas (1) We have developed a new method for state-to-state collisional energy transfer in crossed molecular beams, based on high sensitivity direct IR laser absorption, and allowing absolute cross sections to be obtained by measurement of absolute number densities of the scattering species (CH4H20HF with rare gases). (2) Polarization methods have been developed to study alignment of J states - based on rapid modulation (75 kHz) of a single mode diode laser, and used to study collisional alignment of CO2 in supersonic jets. (3) High resolution flash kinetic spectroscopy has been used to investigate reaction kinetics of OH radical with hydrocarbons, as well as to obtain absolute quantum yields for photofragmentation of HNO3 and H202 at 193 nm and 248 nm. (4) Pressure broadening rates of OH radical relevant to IR 'airglow' detection and characterization have been measured. (5) A new capability has been developed for measuring state-resolved energy transfer in 'hot atom' collisions of open shell radicals. By absolute absorbance measurements and analysis of high resolution Doppler profiles, both integral and differential cross sections to a specific final J state are obtained for Cl + HCL scattering. Infrared airglow, Energy transfer, Potential energy surfaces, Li dopplerimetry.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 28, 1994
- Accession Number
- ADA277372
Entities
People
- David J. Nesbitt
Organizations
- University of Colorado Boulder