High frequency excitation of vapours produced by hollow cathode sputtering

Using a hollow cathode discharge for producing a suitable atomic vapour, the spectral lines of elements were excited by a high frequency discharge of 2450 MHz. These lamps were used as primary light sources for atomic absorption spectroscopy and were compared with conventional hollow cathode lamps. Higher intensity of radiation as well as higher sensitivity was obtained with the high frequency discharge. The interaction of the microwave field with the hollow cathode discharge limits the ultimate intensity. The stability of radiation from these sources is good. Measurements of line halfwidths indicate gas temperatures of approximately 500°K for both the high frequency and conventional hollow cathode discharges.