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

Abstract

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.

Authors:
; ;  [1]
  1. Atomic and Molecular Physics Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan)
Publication Date:
OSTI Identifier:
20982124
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevA.75.022710; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ABSORPTION; CROSS SECTIONS; DENSITY; ELECTRONIC STRUCTURE; IONS; LASER RADIATION; LITHIUM; OSCILLATOR STRENGTHS; PHOTOIONIZATION; PHOTON-MOLECULE COLLISIONS; QUANTUM NUMBERS; RYDBERG STATES; SATURATION; SPECTRA; WAVELENGTHS

Citation Formats

Hussain, Shahid, Saleem, M., and Baig, M. A.. Measurement of oscillator strength distribution in the discrete and continuous spectrum of lithium. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.022710.
Hussain, Shahid, Saleem, M., & Baig, M. A.. Measurement of oscillator strength distribution in the discrete and continuous spectrum of lithium. United States. doi:10.1103/PHYSREVA.75.022710.
Hussain, Shahid, Saleem, M., and Baig, M. A.. Thu . "Measurement of oscillator strength distribution in the discrete and continuous spectrum of lithium". United States. doi:10.1103/PHYSREVA.75.022710.
@article{osti_20982124,
title = {Measurement of oscillator strength distribution in the discrete and continuous spectrum of lithium},
author = {Hussain, Shahid and Saleem, M. and Baig, M. A.},
abstractNote = {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.},
doi = {10.1103/PHYSREVA.75.022710},
journal = {Physical Review. A},
number = 2,
volume = 75,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}
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