The applicability of nanosecond infrared (IR) transversely excited
atmospheric (TEA) CO2 laser, operating at 10.6 ?m and 100 ns pulse length
(initial spike), induced plasma under reduced air pressure for
spectrochemical analysis of bronze and brass samples was investigated. The
plasma consisted of two clearly distinguished and spatially separated regions
and expanded to a distance of about 10 mm from the surface. Elemental
composition of the samples was determined using a time-integrated
space-resolved laser-induced plasma spectroscopy (TISR-LIPS) technique. Sharp
and well resolved spectral lines mostly atomic, and negligibly low background
emission, were obtained from a plasma region 7 mm from the target surface.
Good signal to background and signal to noise ratios were obtained. Estimated
detection limits for trace elements Mg, Fe, Al and Ca were in the order of 10
ppm in bronze and around 50 ppm in brass. Damage on the investigated samples
induced by TEA CO2 laser radiation was negligible.
Effect of gas pressure and pulse length on the isotopically selective multiphoton dissociation of CF3Cl under CO2 laser pulses
