Über den partnereffekt, den leicht ionisierbare elemente in atomspektroskopischen lichtquellen verursachen—I: Experimentelle untersuchung dieses partnereffektes an einem nicht stromführenden plasmastrahl, einschließlich eines vergleichs zwischen plasmastrahl und bogen

Abstract

The interelement effect, which is caused by easily ionizable elements, is investigated experimentally in a non-current carrying plasma jet. Firstly it is shown for a few elements of different ionization potential, that changes in line intensities which occur in this light source, are smaller than those observed in a stabilized arc. It is further shown, that the distribution of temperature in the plasma jet is independent of the composition of the introduced aerosol, which means that the observed changes in line intensities are not due to changes in temperature. Adding different amounts of potassium to the plasma and measuring the partial pressure distribution of Mg-atoms and Mg-ions, it can be shown, that the shift of the ionization equilibrium contributes to changes of these pressures, but is not the dominating reason for them. This follows from the fact, that at any concentration of potassium, both, the partial pressure of atoms as well as that of ions is found to be higher than without potassium. The same holds of course for the sum of both pressures, which comes to a relative maximum at comparatively low concentrations of potassium. Since the plasma jet is not carrying current and since there does not exist an external electrical field in axial direction in it, changes of the internal field due to ambipolar diffusion in radial direction must be assumed to be responsible for the changes in mixing ratios.