Flash-Absorption Spectra of the Plasmas of Arcs and other Discharges

A technique is described in which a heavily loaded flash discharge is employed as a background source for observation of absorption spectra, when the absorbing gas column is strongly excited and, therefore, itself brightly luminous. Examples of the absorption spectra of the plasmas of several arc discharges, of both open and screw-stabilized type, are reproduced. Photometric determination of the total absorption under a number of lines, combined with relative emission intensities, yield values of line-reversal temperatures; some first results are reported for copper arcs.