J. Phys. IV France 03 (1993) C6-217-C6-226
First observation of a Fano profile following one step autoionization into a double photoionization continuumL. JOURNEL1, B. ROUVELLOU1, D. CUBAYNES1, J.M. BIZAU1, F.J. WUILLEUMIER1, M. RICHTER2, P. SLADECZEK2, K.-H. SELBMANN2, P. ZIMMERMANN2 and H. BERGERON3
1 Laboratoire de Spectroscopie Atomique et Ionique, Université Paris Sud, URA 775 du CNRS, B. 350, 91405 Orsay, France
2 Technische Universität, Berlin, Germany
3 LURE, CNRS-CEA-MEN, Université Paris Sud, B. 209d, 91405 Orsay, France
We have measured the double photoionization cross section of sodium atoms between the first 2s22p5 2P double photoionization (52.4 eV) and 2s-single 1.3S photoionization thresholds (71.0 eV). We have also observed a Fano profile into the double ionization continuum resulting from the interference between the one-step direct double photoionization process and the resonant double Auger decay of core-excited neutral sodium in the 2s → 3p resonance region. Profiles of absolute partial and total cross sections have been obtained in all important channels. The Fano and Starace parameters, in particular a width of 0.23 eV, have been determined, allowing full characterization of the resonance.
© EDP Sciences 1993