Collisional removal of O2(b1Σg+,v=1,2) by O2, N2, and CO2

A state-specific two-laser technique is used to investigate the collisional removal of O-2 molecules in the b (1)Sigma(g)(+) (v = 1,2) levels, where we directly excite O-2 and then probe the populations by resonance-enhanced multiphoton ionization. We find general agreement with earlier 300 K values for v = 1 removal by O-2, and show that v = 2 removal is slower by a factor of 5.6 +/- 0.6 than v = 1 removal. Only upper limits are obtained for N-2 as a collider. For removal of v = 1 in the atmosphere, N-2 is unimportant compared to O-2, but it might be competitive for v = 2. For CO2 as a collider, addressing O-2(b (1)Sigma(g)(+)) removal in the atmospheres of Mars and Venus, the removal rate coefficients of the vibrationally-excited levels are similar to that for v = 0. The significance of the large difference in the v = 1 and v = 2 rate coefficients for O-2 collisions will be discussed as it relates to the modeling of recent earth nightglow observations. (C) 1998 American Institute of Physics.