Pressure effects on the Cl2 (D′-A′) transition at 258 nm Original Research Article

UV emission at 258 nm from the transition of Cl2(D′-A′) was investigated by photoexcitation of the Rydberg states at pressures between 1 and 100 Torr. The intensity of the UV fluorescence produced was increased by a factor of two when the pressure of the buffer gas N2 was increased from 1 to 20 Torr. Characteristic pressures for quenching and fluorescence enhancement were derived. Kinetic studies revealed the mechanism of the interstate transitions about the generation of the D′-A′ transition. A vibrational state redistribution in the excitation spectra for the 21Σu+ state at high pressure was observed. The cause of this is explained in terms of state-dependent quenching.