Berlin 2001 – scientific programme

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P: Plasmaphysik

P 7: Dusty Plasmas, Diagnostics III

P 7.5: Talk

Thursday, April 5, 2001, 17:40–17:55, 2032

Measurement of the Atomic Hydrogen Density Distribution in Flames by Two-Photon Polarization Spectroscopy — •A. Steiger¹, A.B. Gonzalo², K. Grützmacher¹, M.I. de la Rosa², and M. Steiger¹ — ¹Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, D 10587 Berlin — ²Dpto. de Optica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, E 47071 Valladolid, Spain

With laser spectroscopic techniques used so far, measurements of atomic number densities in flames and other combustion processes at atmospheric pressure yield no satisfying results because high quenching rates remarkably reduce the signal size and the results suffer from large uncertainties [1]. Two-photon polarization spectroscopy [2] is not limited by quenching and has been used for the determination of the number density and the kinetic temperature of atomic hydrogen in flames for the first time. The great potential of this method comes into its own only in conjunction with laser radiation of highest possible quality in the UV, i.e. 2.5 ns laser pulses with energies of up to 10 mJ within a bandwidth of 300 MHz, tunable around 243 nm.

[1] K. Kohse-Hönighaus, Prog. Energy Combust. Sci. 20 (1994) 203-279

[2] R. Dux, K. Grützmacher, M.I. de la Rosa and B. Wende, Phys. Rev. E 51 (1995) 1416-1427