Accession Number : ADA191857

Title :   Molecular Sources of Ionospheric Holes.

Descriptive Note : Final rept. 1 Apr 84-30 Sep 87,

Corporate Author : SMITHSONIAN ASTROPHYSICAL OBSERVATORY CAMBRIDGE MA

Personal Author(s) : Guberman, Steven L

PDF Url : ADA191857

Report Date : 19 Nov 1987

Pagination or Media Count : 50

Abstract : The dissociative recombination of molecular ions with electrons determines many of the properties of the Earth's ionosphere under both quiescent and disturbed conditions. However, in spite of its importance, there has never been an experimental measurement of dissociative recombination rates from individual excited ion vibrational levels. Completed are large scale ab initio calculations of cross sections and rates for the dissociative recombination of the molecular oxygen ion leading to excited oxygen atoms in the lS and ID states, the upper states of the well known green and red lines, respectively. A new method for calculating electronic autoionization widths using high Rydberg state wave functions to represent the inner part of the free electron wave function has been used and tested on the NO molecule where the widths can be calculated to an expected accuracy of about 15%. THe widths have been used to determine dissociative recombination cross sections as a function of electron energy. Large windows have been discovered in the cross sections from excited vibrational levels. The windows, at which the cross sections drop precipitously, are due to the overlap of the peak in the continuum vibrational wave functions.

Descriptors :   *IONOSPHERE, *MOLECULAR IONS, *RECOMBINATION REACTIONS, *EMISSION SPECTRA, *MOLECULAR VIBRATION, ACCURACY, ATOMS, CROSS SECTIONS, DISSOCIATION, EARTH(PLANET), ELECTRON ENERGY, ELECTRONICS, ELECTRONS, FREE ELECTRONS, HOLES(OPENINGS), IONIZATION, IONS, MEASUREMENT, MOLECULAR PROPERTIES, MOLECULES, OVERLAP, OXYGEN, PEAK VALUES, RATES, SOURCES, WAVE FUNCTIONS, WIDTH

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE