Estimated mass loss due to evaporation for zinc cathodes in analytical glow discharges

Abstract

We present a simple model suitable for estimating the mass loss due to evaporation of cathode material in conditions typically used in glow discharge optical emission spectroscopy (GDOES). This model is then used to calculate the net evaporated flux vs. surface temperature for zinc for different anode diameters and gas pressures. The conclusion from this work is that evaporation can contribute to the mass loss of the cathode and hence the density of the vapor in the gas phase for zinc (a high vapor pressure material) if the cathode surface temperature is high. For a given surface temperature, the importance of evaporation in GDOES depends on background gas density and anode diameter.