Photoionization spectroscopy of even-parity autoionizing Rydberg states of argon atoms

We use the J=0 and J=2 metastable states of argon created in a plasma discharge to perform photoionization spectroscopy of even-parity autoionizing Rydberg states of the argon atom between the first and second ionization limits. Fitting the data to a linear combination of Fano-type peaks allows us to extract the widths and q-parameters of the resonances. Finally, we compare the experimental profile of p-type multiplets to the results of recent theoretical calculations [1]. Agreement is good. \newline [1] I. D. Petrov, V. L. Sukhorukov, T. Peters, O. Zehnder, H. J. Worner, F. Merkt, H. Hotop, JPB 39 p. 3159 (2006)