UV absorption of vibrationally excited ozone

The opportunity of detecting vibrationally excited ozone molecules using UV absorption spectroscopy in the Hartley band was studied. The proposed approach is based on comparing the experimentally measured absorption spectrum with the simulated one. For this purpose the absorption spectra for 35 lower vibrational states ((1)A(1), v(1)v(2)v(3)) in the Hartley band were simulated from ab initio calculations of O(3) photodissociation dynamics by the method of pseudo-coherent states (PCS). A comparison between this method and the known so-called 'frozen' Gaussians (FGA) method was carried out. The limitations of the applicability and accuracy for both methods were considered. The calculation results also were compared with available data of experiments and stricter ab initio calculations. It was shown that despite its approximate character the calculation method used in this paper provides a very sufficient accuracy in calculating correctly the absorption spectrum 'envelope' for all the lower vibrational states of O(3). Furthermore the given approach was applied in detecting O(3)(vib) in the plasma of a glow dc discharge in pure O(2). The analysis of the experimental data on absorption spectra and density distributions of O(3) molecules allowed us to estimate the vibrational temperature of ozone stretching modes in the discharge volume as -800 +/- 150 K (at the gas temperature of similar to 350 K as it was measured).