Photoionization experiments by multistage excitation in the zone of the second ionization threshold of CuI

The conditions of the first double excited configuration of CuI were measured, and interference effects of these conditions were examined with Rydberg series. A multistage excitation was used in order to reach the zone of the second ionization threshold with laser spectroscopic methods. Atomic copper is vaporized in an atomic beam oven in which a burning gas discharge in the oven simultaneously induces a collision excitation in the metastable state of CuI. Photoionization spectra are calculated using the results obtained from Hartree-Fock computations. The measured Rydberg conditions are analyzed using quantum defect theory.