Quantitative Ausmessung des Chlor-Affinitätskontinuums

Abstract

The radiation emitted from the axis of a low current cylindric arc in chlorine was quantitatively recorded. In the UV-region appears the affinity-continuum of chlorine which begins at a longwave threshold of 3428 A yielding an electron-affinity for Cl of 3.616 eV. With spectroscopic temperature measurements and by means of Kirchhoff’s law, the absorption coefficient of the affinitycontinuum is obtained after separation from the background with a linear extrapolation. Thereby the detachment cross section of the negative chlorine-ion is calculated as a function of photon energy. Deviations from thermodynamic equilibrium are accounted for.