Accession Number : AD0719737

Title :   Autoionization in the Ultraviolet Photo-Absorption of ATOMIC Calcium.

Descriptive Note : Research rept. Jul 66-Sep 68,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

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

Report Date : 19 FEB 1971

Pagination or Media Count : 25

Abstract : The study of calcium is of interest because of its solar and astrophysical importance. Also, its photo-absorption spectrum in the uv can be used profitably in the development of theoretical techniques for understanding the general process of autoionization in atomic systems. Results are presented of a combined theoretical and experimental investigation of the absorption spectrum for the allowed dipole transitions singlet S(0) to singlet P(1)(0) of calcium near the first and beyond the second ionization limits. Absorption spectra were obtained experimentally and compared with theoretical calculations. These calculations made allowances for configuration interaction through an analysis of series perturbations in accordance with the multichannel quantum defect theory. Significant improvements have been achieved in the agreement between experiment and the two-channel theory for wavelengths near the ionization threshold, both in the general shape of the absorption profile, and in its magnitude at threshold and at the first resonance peak. Application of the three-channel theory to the latter region is discussed briefly. (Author)

Descriptors :   (*CALCIUM, *ATOMIC SPECTROSCOPY), (*IONIZATION, CALCIUM), ABSORPTION SPECTRA, ELECTRON TRANSITIONS, ATOMIC ENERGY LEVELS, EXCITATION

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE