Abstract

Laser-enhanced ionization spectrometry with two-step excitation has been used to evaluate the collisional lifetime of the metastable P levels of thallium and lead in an air-acetylene flame burning at atmospheric pressure and supported by a three-slot burner head fitted on a conventional nebulizing chamber. A water-cooled molybdenum electrode immersed in the flame was maintained at high negative potential with respect to the burner body. The ionization current resulting after the two-step excitation was amplified and measured with a digital storage oscilloscope and a boxcar averager. The two excimer lasers were triggered externally with two trigger pulses, one being delayed in time with respect to the other one. In this way the second laser photon, tuned at a transition starting from the metatable level under study, could be correspondingly delayed from the first photon tuned at a transition starting from the ground state. The lifetimes measured were found to be 81 ns and 360 ns for TI and Pb, respectively.

Laser-based spectroscopic technique for fast and reliable measurements of lifetimes of atomic metastable states in combustive situations

Ove Axner, Peter Ljungberg, and Yvonne Malmsten
Appl. Opt. 32(6) 899-906 (1993)

Acetylene measurement in flames by chirp-based quantum cascade laser spectrometry

Zachary R. Quine and Kevin L. McNesby
Appl. Opt. 48(16) 3075-3083 (2009)

Detection of trace amounts of Cr by two laser-based spectroscopic techniques: laser-enhanced ionization in flames and laser-induced fluorescence in graphite furnace

Ove Axner and Halina Rubinsztein-Dunlop
Appl. Opt. 32(6) 867-884 (1993)

Laser-enhanced flame ionization detector

Terrill A. Cool and John E. M. Goldsmith
Appl. Opt. 26(17) 3542-3551 (1987)

Picosecond laser-spectroscopy measurement of hydroxyl fluorescence lifetime in flames

Neal S. Bergano, Paul A. Jaanimagi, Michael M. Salour, and James H. Bechtel
Opt. Lett. 8(8) 443-445 (1983)