Applied Physics B

, Volume 74, Issue 1, pp 101–104

Effective A-state fluorescence lifetime of formaldehyde in atmospheric pressure CH4/air flames

  • J. Tobai
  • T. Dreier

DOI: 10.1007/s003400100739

Cite this article as:
Tobai, J. & Dreier, T. Appl Phys B (2002) 74: 101. doi:10.1007/s003400100739

Abstract.

Using excitation pulses of ∼30-ps duration and a fast photomultiplier detector, effective fluorescence lifetimes of the A-stateof formaldehyde after excitation at 355 and 339 nm have been measured in the preheating zone of an atmospheric pressure, premixed methane/air flame. The fluorescence lifetimes were determined as a function of height above the exit of a slot burner and were thus probed in regions of varying gas temperature and composition. The fluorescence lifetimes were independent of the intensity of the excitation pulse and decreased as a function of height in the burner from ∼18±8 ns at 1.2 mm down to 7±1 ns at 3.8 mm. This trend of the effective fluorescence lifetime with composition and temperature in the flame can qualitatively be reproduced using calculated major species mole fractions and species-specific quenching cross sections for CH from the literature.

PACS: 33.50.-j; 42.62.Fi

Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  • J. Tobai
    • 1
  • T. Dreier
    • 1
  1. 1.Physikalisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg, GermanyDE