Observation of characteristic, polarity-dependent, Doppler shifts from neutral species in the positive column of a discharge plasma

22 November 1995

journal article
Published by AIP Publishing in The Journal of Chemical Physics

Vol. 103 (20) , 8821-8827
https://doi.org/10.1063/1.470070

Abstract

Doppler shifts of emissions from neutral species have been observed for the first time in a positive column of a dc glow discharge. For a detailed study, we have chosen emissions of H2 and its isotopomers in a hydrogen discharge using a high resolution Fourier-transform spectrometer. Experimetal evidence supports the conclusion that the observed shifts derive from momentum transfer during electron-molecule collisions that produce the emissive excited states. A theoretical model has been formulated to relate Doppler shifts to the drift velocity of electrons in the discharge as well as to the momentum transfer of electron-molecule collisions. Predictions based on the model are consistent with the experimental observations.

Keywords

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