COLLISIONAL REMOVAL OF O-2(B(1)SIGMA(-2, N-2, AND CO2()(G),V=1,2) BY O)

A state-specific two-laser technique is used to investigate the collis ional removal of O-2 molecules in the b (1)Sigma(g)(+) (v = 1,2) level s, where we directly excite O-2 and then probe the populations by reso nance-enhanced multiphoton ionization. We find general agreement with earlier 300 K values for v = 1 removal by O-2, and show that v = 2 rem oval is slower by a factor of 5.6 +/- 0.6 than v = 1 removal. Only upp er 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 co mpetitive 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 f or 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 relat es to the modeling of recent earth nightglow observations. (C) 1998 Am erican Institute of Physics.