Accession Number:

ADA210678

Title:

LABCEDE Fluorescence Investigations

Descriptive Note:

Final rept. 30 Nov 1984-29 Feb 1988

Corporate Author:

PHYSICAL SCIENCES INC ANDOVER MA

Report Date:

1988-08-01

Pagination or Media Count:

551.0

Abstract:

This report covers a wide variety of projects to measure and interpret the fluorescence arising from electron excitation of atmospheric gases. Excitation of nitrogen B-state is Franck Condon at low pressure but as pressure increases to tens of mtorr, collisional transfer from the A-state into the lowest B-state vibrational levels is observed. The middle levels of the B- state show little variation with pressure even though they strongly coupled to W-state levels. The N2a1 pi g state was observed via LBH emission at 0.2 micrometers. Substantial vibrational redistribution rather than electronic quenching was observed. Again nested electronic states in particular the a- state are involved in the relaxation. Level-specific investigations of the N2a, v0 relaxation by a variety of gases including N2 and oxygen is also reported. Electron impact excitation cross sections for N2 A, v2-7 were measured at sufficiently low pressures that quenching effects can be removed. Data from two infrared spectrometers are used to determine the contributions of various N2 transitions to the IR spectrum observed in LABCEDE. Emission from N2O2 irradiated mixtures were also studied. Ozone fluorescence is observed. Data from early field mission seemed to indicate that the auroral fluorescence spectrum was different under sunlit conditions. The LABCEDE Facility was used to provide an understanding of electronN2 molecular scattering processes.

Subject Categories:

  • Atmospheric Physics
  • Physical Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE