Vergleich von Hochdruck- und Niederdruck-Quecksilberbrennern als Raman-Erreger Lichtquellen

Abstract

For some years low-pressure mercury-vapour tubes of the Toronto type have been employed in America as radiation sources for Raman excitation. European authors, however, ordinarily use the Raman lamp with the usual mercury-vapour high-pressure tube of quartz. Very accurate data of the electrical and optical properties exist for the latter; in the case of the Toronto-lamps, however, no data, with the exception of a few details given in the ARL-prospectus, are known which will permit of a comparison with the high-pressure tube. Such a comparison has now been made with a Raman source, which has been constructed in this laboratory. It differs slightly from the ARL lamp and it is illuminated by a mercury low-pressure tube. Apart from the electric properties (current-voltage characteristics and their dependence on the temperature of the cooling water) the following optical properties of importance in Raman spectroscopy were examined in this comparison: the relationship of the intensities, widths and shapes of the mercury-vapour Unes and the intensity of Raman Unes as compared with those given by a Steinheil Raman lamp, with or without projection in the spectrometer; measurements of the background of both lamps have also been made. In essential aspects this comparison favours the low-pressure lamp as Raman source.