Potential energy curves of Xe2 derived from the pressure-dependent fluorescence excitation spectra of the 1st and 2nd continuum

The composition of the Xe system changed from mainly atomic at low pressure to molecular at high pressure. The energy levels of this system varied also. By using the fluorescence of the first and second continuum measured near the resonant line of Xe at 147 nm at various pressure conditions, we observed the formation of Xe2 and the energy levels for the excited states A1u, B0u+ and B′1u states. In a potential energy diagram, this corresponds to the change of energy levels from R≈∞ to finite R.