VISIBLE RADIATION FROM ILLUMINATING FLARE FLAMES,
Abstract
Spectra of flames from pyrotechnic flares containing magnesium plus nitrates of lithium, sodium, potassium, rubidium, cesium, strontium, or barium are presented to show emission in the visible and near-infrared regions. The strongest feature in each of the alkali metal spectra is the strong, broad 'resonance line continuum' in the resonance region appropriate to each metal. Most of the light from a sodium flare originates from continuous emission composed of the resonance line continuum and the background continuum. In the alkali metal spectra, atomic lines (other than the sodium D lines) and molecular bands account for only a small amount of the luminous energy emitted from the flame. In contrast, band emissions are the strongest feature of strontium and barium flame spectra. When alkali metals are present in high concentrations, the emission associated with the alkali metal resonance lines has a deep minimum of intensity at the resonance frequency with intensity maxima as much as 100A on either side of the line center frequency. As the pressure of the atmosphere surrounding the flame is reduced, there is a marked change in spectral distribution of the radiant energy and a reduction of the intensity of the resonance line continuum and the background continuum. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1969
- Accession Number
- AD0688769
Entities
People
- Bernard E. Douda