Accession Number : AD0664561

Title :   BANDWIDTH DEPENDENCE OF MEASURED ULTRAVIOLET ABSORPTION CROSS SECTIONS OF ARGON,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s) : Hudson,Robert D. ; Carter,Virginia L.

Report Date : NOV 1967

Pagination or Media Count : 29

Abstract : The atomic absorption cross section of neutral argon between the (2)P3/2 and (2)P1/2 states of the Ar(+) ion was measured at an instrumental bandwidth of 0.04A. Accurate line shapes for the (3s)(2) (3p)(5) (2)P1/2 nd' transitions have been obtained for n = 9 to 20. Also presented are oscillator strengths and line positions for n = 9 to 30. In the course of this investigation, an analysis was made of the effect of instrumental bandwidth on measured absorption cross sections and line shapes in the ultraviolet. It is demonstrated that, contrary to the assumptions made by many ultraviolet spectroscopists, a linear 'Beer's Law' plot does not necessarily indicate that a true peak or minimum absorption cross section has been measured. Errors of as much as a factor of two can be introduced by this assumption. The results presented in this paper were corrected for this effect. Discrepancies between these and earlier measurements are shown to be consistent with the analysis. (Author)

Descriptors :   (*ARGON, *ULTRAVIOLET SPECTROSCOPY), NUCLEAR CROSS SECTIONS, ATOMIC ENERGY LEVELS, ABSORPTION SPECTRA, PROBABILITY, LINE SPECTRA, BANDWIDTH, ULTRAVIOLET SPECTRA, VISIBLE SPECTRA

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE