Single-photon ionization study of the vibrational structure in the ground state of Xe+2

Abstract
The vibrationally resolved spectra of the ground state A 2 Sigma +u of Xe+2 were observed at wavelengths from 1023 AA to 1116 AA by using the method of single-photon ionization with synchrotron radiation as a light source. A long progression beginning at v=0 was clearly observed in the threshold electron spectra for the first time. The spectroscopic parameters for the ground state of Xe+2 (average mass=131.3, 131.3) calculated from the experimental data are: omega e=122.9 (+or-0.1) cm-1 omega e chi e=0.481 (+or-0.001) cm-1, the dissociation energy D0=7849 (+or-9) cm-1, the zero point energy 61.3 (+or-0.1) cm-1, Te=90 119 (+or-8) cm-1, and the adiabatic ionization potential 90 170 (+or-8) cm-1. Autoionizing Rydberg series were found and assigned to converge to the C 2 Pi 32u/ and B2 Pi 12g/ states of Xe+2.