Spectrochemical Analysis Using Low-Background Laser Plasma Induced by Nd-YAG Laser at Low Pressure

Abstract

It was demonstrated that the atomic emission lines emitted from a low-background plasma which is produced when a Q-switched Nd-YAG laser (28 mJ, 1064 nm, 8 ns) is focused on a sample at a reduced pressure of 0.5 Torr, can be successfully applied to microarea analysis of samples such as stone. In this regard, it was stressed that analytical equipment can be constructed at low cost using low-background plasma spectroscopy because the gated optical multichannel analyzer (OMA) which is normally used in laser plasma spectroscopy can be replaced by a much simpler OMA system without gating. By comparing the results obtained by low-background plasma spectroscopy and those obtained using an electron-probe microanalyzer (EPMA), it was shown that by using this laser method, a much more sensitive analysis can be achieved. By attaching a small chamber directly to the sample surface with the aid of an o-ring, and applying this laser method, we can construct an in-situ mobile analytical system for use in fields such as geology and archeology.