Doubly excited resonances in the photoionization spectrum of Li+: experiment and theory

• Published in: Journal of physics. B, Atomic, molecular, and optical physics Vol. 39; no. 18; pp. 3957 - 3968
• Main Authors: Scully, S W J, Álvarez, I, Cisneros, C, Emmons, E D, Gharaibeh, M F, Leitner, D, Lubell, M S, Müller, A, Phaneuf, R A, Püttner, R, Schlachter, A S, Schippers, S, Shi, W, Ballance, C P, McLaughlin, B M
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 28.09.2006; Institute of Physics
• Subjects: Atomic and molecular physics; Atomic properties and interactions with photons; Autoionization; Exact sciences and technology; Photoionization of atoms and ions; Photon interactions with atoms; Physics; Multiple ionization; Photoionization; Rydberg states; Lithium Atomic ions; Autoionization; Resonance energy; R matrix; Positive ions; Cross sections
• ISSN: 0953-4075; 1361-6455
• DOI: 10.1088/0953-4075/39/18/024

Absolute cross-section measurements for resonant double photoexcitation of Li+ ions followed by autoionization have been performed at high resolution in the photon energy range from 148 eV, just below the (2s2p, 2(0, 1)n+) resonance, to 198 eV (the region of the double ionization threshold). The measurements have been made using the photon-ion merged-beam endstation at the Advanced Light Source, Lawrence Berkeley National Laboratory, USA. The absolute cross-section measurements show excellent agreement with theoretical results from the R-matrix plus pseudo-state (RMPS) method. Comparisons between theory and experiment for the Auger resonance energies, autoionization linewidth (Gamma) and the Fano line profile index q for several members of the principal (2snp, 2(0, 1)n+) and (3snp, 3(1, 1)n+) Rydberg series found in the photoionization spectra for the 1Po symmetry show satisfactory accord.