Studies on the fundamental characteristics of laser ablation/low-pressure inductively coupled plasma

We designed a low-pressure inductively coupled plasma (LP-ICP) with a laser ablation chamber that was used for solid sample introduction, and we investigated the fundamental characteristics of Ar and He ICPs with the LP-ICP. Fundamental characteristics of Ar and He ICPs. at low pressure were studied by measuring excitation temperature and electron number density as operating conditions such as forward power, discharge gas flow rate, and pressure were varied. Excitation temperatures of Ar and He LP-ICPs were independent of the operating conditions, but the electron number density of Ar ICP showed a significant change as the operating conditions were varied. The electron number density of He LP-ICP could not be determined because the Stark width of He LP-ICP was too small to be measured with the resolution of the spectrometer employed in this work. The excitation temperatures of Ar and He LP-ICPs were approximately 4200-4500 K. The electron number density values of Ar LP-ICP were found to range from 2.63 x 10(14) to 5.75 x 10(14), (C) 1999 Academic Press.