Ground and excited states of Xe+2 observed by high resolution threshold photoelectron spectroscopy of Xe2

Threshold photoelectron spectra of the xenon dimer have been observed with a resolution of 2 meV in the wavelength range 920–945 Å and 1022–1112 Å using the penetrating field technique and synchrotron radiation. Threshold photoelectron bands associated with transitions to the A2 Σ+1/2u, B2 Π3/2g, C2 Π3/2u, C2 Π1/2u, and D2 Σ+1/2g states of Xe+2 have been identified. Vibrational structure associated with the C2 Π1/2u state has been observed for the first time and a new value of the D2 Σ+1/2g state ionization potential is reported.