Effect of metal clusters on the absorption and emission spectra of high-density sodium vapors

Abstract

The optical absorption spectra of high-density (1016–1019 cm−3) sodium vapors were studied in a broad spectral range (0.35–1.1 μm). The intensity of thermal radiation from sodium vapors was measured in the 2–3 μm wavelength interval. It is established that the effect of metal clusters can account neither for the observed structure of absorption spectra nor for the increased intensity of emission in the near-IR range reported in some works (in particular, for the emission spectra of high-pressure gas-discharge sodium lamps).