Heidelberg 1999 – scientific programme

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K: Kurzzeitphysik

K 2: Kurzzeitdynamik (Poster)

K 2.1: Poster

Monday, March 15, 1999, 16:30–18:30, GE1

Spectroscopic and time resolved investigation of picosecond laser induced fluorescence from polycyclic aromatic hydrocarbons at elevated temperatures — •Thomas Metz, Frederik Ossler, and Marcus Aldén — Department of Combustion Physics, Lund Institute of Technology, P.O. Box 118, S-221 00 Lund, Sweden

Spectrally and temporally resolved laser-induced fluorescence (LIF) measurements on polycyclic aromatic hydrocarbons in the gas phase at atmospheric pressure, temperatures ranging from 150 ^∘C to 900 ^∘C and oxygen concentrations between 0 and 10 % have been performed. The studied species were fluorene, naphthalene, anthracene and pyrene. They were excited at 266 nm by a picosecond Nd:YAG laser with a pulse duration of less than 35 ps. The results show that the lifetimes decrease with increasing temperature while in the spectral profiles broadening effects and red shifts have been observed. Oxygen had a quenching effect on the lifetimes at temperatures less than 500 ^∘C. In a premixed methane/air flame seeded with PAH in the post flame zone spectrally and temporally resolved LIF measurements were performed at different equivalent ratios.