Absolute emission intensity measurements of the radiation from sulfur molecules S2have been obtained in the temperature range from 2300 to 4800deg;K at six wavelengths spaced between 3132 and 5461 Aring;. The radiation intensities were proportional to the square of the sulfur atom concentration and were independent of the total pressure of the buffer gas, argon. In addition, the band structure was recorded for the wavelength interval 3600ndash;4100 Aring; with an image orthicon camera mounted in a spectrograph. The intensities between 3650 and 5461 Aring; have similar activation energies and are interpreted in terms of the radiative transitions from theB3Sgr;uminus;state of molecular sulfur, this state being populated by the mechanism of inverse predissociation. Theoretical calculations of theB3Sgr;uminus;bands predicted the band shapes observed with the image orthicon and, together with the measured intensities, provide the electronicfvalue for the bands. The square of the transition momentlsqb;Relpar;rrpar;thinsp;sol;thinsp;ea0rsqb;2is estimated to have a value of 5.0, which corresponds to anfvalue of 0.16 on the basis of published Franckndash;Condon factors. The intensities at 3132 Aring; have a temperature dependence close to that predicted for transitions from theb1Dgr;uelectronic state.
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