New Method of Laser Plasma Spectroscopy for Metal Samples Using Metastable He Atoms Induced by TEA CO{sub}2 Laser in He Gas at 1 atm

摘要

A high power TEA CO{sub}2 laser was focused on a metal target in He gas at 1 atm to produce strong He gas breakdown plasma, while leaving the metal surface undamaged, and a Q-switched Nd:YAG laser was simultaneously focused on the metal surface to be ablated at a slightly shifted spot position with various delay times relative to the TEA CO{sub}2 laser. It was concluded that the ablated atoms are excited by metastable He atoms. The detected atomic emission lines are very narrow in spectral width with a very low background spectrum. We call this new method LIPS-He{sup}*.