ISSN:
1434-6079
Keywords:
PACS. 32.80.Rm Multiphoton ionization and excitation to highly excited states (e.g., Rydberg states) – 32.30.Jc Visible and ultraviolet spectra – 32.80.Dz Autoionization
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract: The even parity 5 pnpJ = 0, 1 and 2 doubly excited autoionizing states of strontium were investigated both experimentally and theoretically. Sr atoms in an atomic beam were excited through the two-step Isolated Core Excitation (ICE) scheme 5s2 1 S 0 -λ 1 → 5 sn'p 1 P 1 ( n' = 12-16)-λ 2 → [5 p 3/2 np ] J . The final ICE transition probes the [5 p 3/2 np ] J resonances. However, the [5 p 1/2 np ] J series below the 5 p 1/2 threshold were excited also due to their mixing with the [5 p 3/2 np ] J perturbers. An extended energy region was covered below and above the 5 p 1/2 ionization limit by saturating the central ICE lobe and recording as many as possible “red” and “blue” secondary lobes. J identification was achieved by using mutually parallel and perpendicular linear polarizations of the laser beams. The ICE spectra were compared to those obtained by employing a two-step excitation scheme using the bound 4 d 5 p 1 P 1 valence state as an intermediate one. Final identification for very complex structures was achieved after comparison with theoretical energy level positions and excitation profiles produced by the R-matrix method combined with the multichannel quantum defect theory (MQDT) method. The agreement between theoretical and observed structures is quite satisfactory.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s100530170263
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