Photoabsorption spectrum of Xe2+ 1(12)u from 248 to 351 nm

Relative photoabsorption cross sections for the 1(12)u'2(12)g band of Xe2+ have been determined at several discrete wavelengths between =248 and 351 nm, the spectral region in which the absorption peaks. Xe+ P322 ions are produced by two-photon ionization of Xe at 193 nm (ArF laser) which dimerize to form Xe2+ ions in the 1(12)u ground state. A second excimer-laser pulse subsequently photodissociates the molecular ion. The results agree with the theoretical 1(12)u'2(12)g ultraviolet absorption curve of Wadt [J. Chem. Phys. 73, 3915 (1980)] except that the cross sections reported here indicate that the band is nearly symmetrical around 340 nm, rather than skewed towards the visible.