MEASUREMENT OF THE LASER INDUCED IONIZATION YIELD FOR LITHIUM IN AN AIR - ACETYLENE FLAME
Single step excitation and two step excitation, followed by collisional ionization, have been used to measure the ionization yield of lithium atoms produced in a separated air - acetylene flame. The excitation is provided by two pulsed, tunable dye lasers, pumped simultaneously by an excimer laser and tuned to two connected transitions of the atom. The ionization signals is taken simultaneously with the fluorescence signal, which is measured with a monochromator and a photomultiplier placed at 90 degrees with respect to the laser beams. The ionization yield for a single step excitation at 670.784 nm was found to be 0.26%, increasing to 58% for two-step excitation (670.784 + 460.286 nm). By use of these values in a simplified theoretical treatment of the ionization process, it is shown that one can obtain order of magnitude estimates of the effective collisional ionization rate coefficients of the process(es) assumed.
Bibliographic Reference: ANALYTICAL CHEMISTRY, VOL. 58 (1986), NO. 11, PP. 2147-2151
Record Number: 1989125030500 / Last updated on: 1987-03-01
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