Arc Spectral Lines of Selenium and Tellurium

Abstract

Several factors limit the detection of selenium by excitation in the dc arc. One, the most persistent lines (1960.9, 2039.9, and 2062.8 A) are in the spectral region that requires a photographic emulsion sensitive to short-wave radiation. Also, plane-grating spectrographs in common use have gratings blazed for maximum speed around 3000 A to take advantage of the sensitive lines of elements in that region, thus lines at shorter wavelengths, below 2500 A, are greatly attenuated. Arc lines of tellurium are more plentiful and favorably located than those of Se, however, the two most persistent lines (2383.3 and 2385.8 A) are weakened by the blaze angle. In prior analysis of Se and Te by the dc arc it was noted that spectral lines occur that can be utilized for the detection of these elements in various materials by conventional dc-arc excitation. In the present study, differences found are compared with published tables.