UV absorption spectra of vibrationally excited O-2 and its accumulation under KrF excimer laser irradiation in a low-temperature Ar crystal

Numerous lines were: observed in the UV absorption spectra of O-2 doped in a low-temperature Ar crystal excited by a KrF excimer laser. These lines were assigned to the transitions From vibrationally excited levels of the ground state O-2 (v '' = 4-11) to vibrational levels of the B state (v' = 0-8), where the B state vibrational numbering of Schnepp and Dressier was adopted. The steady-state concentration of the vibrationally excited O-2 (v '' = 4-8) was estimated to be 3.4 x 10(16) molecules cm(-3), corresponding to 0.07% of the total O-2, under irradiation by the KrF laser at a fluence of 4.9 mJ cm(-2) pulse(-1) with a repetition rate of IO Hz.