Observation and theoretical analysis of the odd J=3 autoionising spectrum of Sr up to the 4d threshold

The odd J=3 autoionising spectrum of Sr between the 5s and the 4d thresholds has been observed. In a Sr atomic beam, the ionised atoms produced by a two-step excitation scheme have been analysed via a time-of-flight spectrometer. A theoretical approach based on the R-matrix method combined with multichannel quantum defect theory calculations provided a good description of the position of the observed lines. Analysis of the observed profiles gave qualitatively good results although the intermediate 5p2 1D2 level is not perfectly described in the model.

[1]  M. Kompitsas,et al.  Multiphoton single and double ionisation of strontium in the range 532-541 nm , 1989 .

[2]  Tang,et al.  Multiphoton spectroscopy of doubly excited, bound, and autoionizing states of strontium. , 1988, Physical review. A, General physics.

[3]  Hansen,et al.  Multiconfiguration Hartree-Fock calculations for singlet terms in neutral strontium. , 1988, Physical review. A, General physics.

[4]  M. Aymar.  Eigenchannel R-matrix calculation of the photoabsorption spectrum of strontium , 1987 .

[5]  C. Nicolaides,et al.  Multi-channel reaction matrix theory and configuration-interaction in the discrete and in the continuous spectrum. Inclusion of closed channels and derivation of quantum defect theory , 1987 .

[6]  Greene,et al.  Two-electron excitations in atomic calcium. I. , 1987, Physical review. A, General physics.

[7]  M. Aymar,et al.  R-matrix calculation of eigenchannel multichannel quantum defect parameters for strontium , 1987 .

[8]  B. Sulik,et al.  On the L-M-N multiple ionisation in heavy elements , 1987 .

[9]  J. Lecomte.  Parametrisation of resonance structures in the multichannel quantum defect theory , 1987 .

[10]  Xu,et al.  Sr 5pnd J=3 autoionizing series and interference of excitation due to bound-state perturbation. , 1987, Physical review. A, General physics.

[11]  Komninos,et al.  Many-electron approach to atomic photoionization: Rydberg series of resonances and partial photoionization cross sections in helium, around the n=2 threshold. , 1986, Physical review. A, General physics.

[12]  A. R. P. Rau,et al.  Atomic Collisions and Spectra , 1986 .

[13]  Agostini,et al.  Electron spectroscopy at thresholds in single and double multiphoton ionization of strontium. , 1985, Physical review. A, General physics.

[14]  Greene.  Channel-interaction theory in a finite volume. , 1985, Physical review. A, General physics.

[15]  P. Grangier,et al.  Experimental and theoretical isotope shifts of strontium levels subject to very strong configuration mixing , 1984 .

[16]  C. Greene.  Atomic photoionization in a strong magnetic field , 1983 .

[17]  M. S. Longmire,et al.  Absorption spectrum of Sr i between 1400 and 1900 Å , 1983 .

[18]  J. Bokor,et al.  Four-wave parametric mixing in optically inverted barium ions , 1982 .

[19]  D. Feldmann,et al.  Resonant double ionisation of strontium atoms by tunable laser radiation , 1982 .

[20]  J. Bokor,et al.  Autoionization-pumped laser , 1982 .

[21]  C. Fischer,et al.  Comparison of multichannel-quantum-defect theory and multiconfiguration-Hartree-Fock wave-functions for alkaline-earth atoms , 1981 .

[22]  J. Connerade,et al.  Potential barrier effects on double excitation series of Ca I and Sr I , 1980, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[23]  J. Rubbmark,et al.  Rydberg Series in Strontium Found in Absorption by Selectively Laser-Excited Atoms , 1978 .

[24]  W. Persson,et al.  Strong configuration interaction between 4d5p 1F and the 5snf 1F series in Sr I , 1977 .

[25]  R. Learner,et al.  Re-examination of the spectrum of strontium: autoionization in the spectrum of neutral strontium , 1973 .

[26]  V. Carter,et al.  Absorption Spectrum of Sr I in the Region of Autoionization from 1646 to 2028 Å , 1969 .

[27]  K. Lu.  Spectroscopy and Collision Theory: the Xenon Absorption Spectrum. , 1972 .

[28]  W. Garton,et al.  Ultra-violet extensions of the arc spectra of the alkaline earths: The absorption spectrum of strontium vapour , 1968 .