総説

減圧下レーザー誘起プラズマと大気圧下TEA CO₂レーザー誘起ガスプラズマを用いる分光分析

Spectrochemical Analysis Using Laser-Induced Plasma at Low Pressure and TEA CO₂ Laser-Induced Metal-Assisted Gas Plasma at 1 atm

香川喜一郎・Ali KHUMAENI
Kiichiro KAGAWA and Ali KHUMAENI

著者らが開発したレーザー誘起プラズマ分光分析に関して総説した．減圧下で生成されるプラズマの原子励起過程には衝撃波が関与していること，そのプラズマの特性は発光分光分析に適していることを述べた．また，減圧下でTEA CO2レーザーを用いれば，金属表面の薄膜などの元素分析が高感度でできること，大気圧下でTEA CO2レーザーを照射する方法で有機粉末や土壌の高感度分析が可能になること，また，TEA CO2レーザーをヘリウム1気圧のもとで金属表面に照射するとヘリウムの準安定状態を多量に生成することができ，これを用いて原子を励起する方法により，これまでにない高感度分析が可能であることを述べた．

A review on the study of the unique methods of laser-induced plasma spectroscopy (LIPS), which was developed by the present authors, is presented. It was proved that the low pressure plasma, in which atoms are excited by the shock wave, has favorable characteristics for spectrochemical analysis. Some of its representative applications are H analysis in zircaloy sample and high sensitive analysis of film attached on the metal surface. Also, it is stressed that TEA CO2 laser can be applied to develop LIPS. One is the application to organic powder analysis, soil analysis, and concrete analysis under 1 atm. The other is the production of a lot of Helium metastable atoms, He*, through which atoms are excited resulting in a spectrum with very low background. This method will be widely used in many fields as in-situ high sensitive analysis.

Keywords: Laser-induced plasma, spectrochemical analysis, TEA CO2 laser-induced plasma, H analysis, He meta-stable atoms