PREDISSOCIATION LIFETIMES OF THE ROTATIONAL AND FINE-STRUCTURE LEVELS OF O2+(B4-SIGMA-G,V=3,4,5)

A fast ion beam coaxial with a single mode laser has been used to measure the absorption linewidths of predissociated levels of O2 +(b 4Σg-, ν = 3,4,5) by detection of the O+ photofragments. Tuning of the absorption wavelength was accomplished by a combination of intracavity etalons and variation of the ion beam velocity (Doppler tuning). Lifetimes were determined for the b state fine structure levels of rotational levels N = 31 and 33 of 16O2+(ν = 3), N = 9-25 of 16O2+(ν = 4), N = 14-27 of 16,18O2+(ν = 4), and N = 5-7 of 16O2+(ν = 5). The lifetimes vary from 0.06 to 4 nsec. Variation with all relevant quantum numbers and with isotopic composition is discussed. © 1979 American Institute of Physics.