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Title: Measurement of oscillator strength distribution in the discrete and continuous spectrum of lithium

Journal Article · · Physical Review. A
; ;  [1]
  1. Atomic and Molecular Physics Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

The oscillator strength distribution in the discrete and continuous regions of the spectrum of lithium has been determined by employing the saturation technique in conjunction with a thermionic diode ion detector. The photoionization cross section from the 3s {sup 2}S excited state at the ionization threshold has been determined by the direct absorption of the 614 nm laser and also from extrapolating the photoabsorption cross sections measured for eight transitions of the 3s {sup 2}S{yields}np {sup 2}P (n=14,16,18,20,22,24,26,28) Rydberg series. The average value of the photoionization cross section measured at the ionization threshold has been used to extract the f values for the 3s {sup 2}S{yields}np {sup 2}P Rydberg series of lithium from n=14 to n=56. The measured f values of the observed Rydberg series decrease smoothly with an increase of the principal quantum number. The oscillator strength densities in the continuum region have also been determined from the measured values of the photoionization cross section from the 3s {sup 2}S excited state at four ionizing laser wavelengths above the first ionization threshold. Continuity has been found between the discrete and the continuous spectrum across the ionization threshold.

OSTI ID:
20982124
Journal Information:
Physical Review. A, Vol. 75, Issue 2; Other Information: DOI: 10.1103/PhysRevA.75.022710; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
Country of Publication:
United States
Language:
English