Rotational excitation of OH in collisions with CO, N2, and CO2

Abstract

Relative state-to-state cross sections are obtained for OH colliding with CO, N2, and CO2. Hexapole state selection is used to prepare a beam of OH molecules in the upper Λ-doublet component of the lowest rotational state. The collision induced rotational energy transfer is monitored state selectively by means of LIF (laser induced fluorescence) spectroscopy. A study is made of the symmetry effects in the obtained cross sections. The results are compared with previously reported cross sections for Ar, He, and H2. A general propensity is found for parity conserving transitions to the Π3/2, J=52 and Π1/2, J=12 states.