Non-metal atomic emission spectrometry in helium surface-wave sustained plasmas at 40 and 2450 MHz

Abstract

The physical characteristics and non-metal analyte emission intensities were compared for helium surface-wave plasmas sustained at 40 and 2450 MHz under otherwise identical operating conditions. The 40 MHz plasma proved to be physically longer and less dense than the 2450 MHz plasma. The non-metal atomic emission line intensities for the 40 MHz plasma were 1–3 times weaker than those for the 2450 MHz plasma when both were axially viewed (end-on). Bromine ionic and atomic emission appeared to be selectively affected by operating frequency, suggesting different kinetics for the excitation of their upper levels.