Using transverse resonant two-photon CW laser excitation of metastable 40Ar(4s 3P2) atoms in a collimated beam via the Ar(4p 3D3) level, we have carried out a comprehensive high-resolution study of odd Ar(2P3/2 ns, nd, J = 2, 3) Rydberg states (n = 13-90). The transition energies are determined with an uncertainty of 0.006 cm-1 and perturbations in the spectra associated with the Ar(2P 1/2 8d′, 9d′, J = 2, 3) levels are clearly detected. Moreover, the low-lying Ar(nd′, J = 2, 3) autoionization resonances (n = 10-14) have been investigated and the respective widths (ranging from 5000 to 26 000 cm-1) determined. A very sharp resonance (reduced width 27 cm-1) has been detected and identified as a member of the ng′, J = 3 series. A multichannel quantum defect theory (MQDT) analysis of the measured bound Rydberg levels yields reliable eigenchannel quantum defect parameters which describe the odd J = 2 and 3 spectra of Ar in the bound as well as in the autoionization region. The MQDT-derived widths for the nd′ resonances are found to be in good agreement with the experimental results. The s-d coupling observed in the J = 2 spectrum is discussed in detail.
|Number of pages||18|
|Journal||Journal of Physics B: Atomic, Molecular and Optical Physics|
|Publication status||Published - 1999 May 28|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics