Berlin 2001 – scientific programme
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P: Plasmaphysik
P 10: Theory and Plasma Diagnostic (Poster Session)
P 10.23: Poster
Wednesday, April 4, 2001, 12:30–15:00, AT2
Investigations of excitation transfer in H2/He/Ar-plasmas by absorption spectroscopy — •M. Berger, U. Fantz, and K. Behringer — Lehrstuhl für Experimentelle Plasmaphysik, Institut für Physik, Universität Augsburg, 86135 Augsburg
The knowledge of populating and depopulating processes is very important for application and further development of emission spectroscopy as a diagnostic method. In low pressure plasmas the excitation and deexcitation by heavy particle collisions can play a role apart from collisions with electrons. The changes in populations of metastable and resonant levels of the rare gases helium and argon with addition of H2 was examined by absorption spectroscopy. In Ar/H2 plasmas a strong depopulation of the levels arises, suggesting excitation transfer. In He/H2-plasmas a deexcitation of helium was observed, which is attributed to heavy particle collisions with H2 or H (quenching). The results of measurements in Ar/H2, He/H2 and Ar/He/H2 mixtures are compared and discussed. Additional information on the population transfer is taken from emission spectroscopy.