Abstract

A tunable infrared diode laser has been used to monitor the time-resolved absorption of ro-vibrationally excited CO₂ molecules produced in collisions with fast hydrogen atoms from the 193nm excimer laser photolysis of H₂S. Nascent relative rotational population distributions were determined for the 00⁰1, 00⁰2, 01¹1 and 10⁰l. The nascent distributions for the four levels were found to be significantly displaced from the 300K Boltzmann distribution with the peaks occuring at J = 33 for 00⁰¹, J=34 for 00⁰2, J=34 for 01¹1 and J=35 for 10⁰1. The absolute T-V/R excitation cross section τσ² for 00⁰1, J=33, was determined to be between 10⁻³ and 10⁻² A², and the total excitation cross-section for the entire 00⁰1 vibrational state is in the range of 0.1 −0.4A².

© 1988 Optical Society of America