Mass Spectrometric and Laser Spectroscopic Characterization

of a Supersonic Planar Plasma Expansion

A mass spectrometric and laser spectroscopic experiment has been performed to characterize reactive species that are formed in a supersonic planar plasma expansion generated by discharging a high-pressure gas pulse in a multi-layer slit nozzle geometry. Discharges through mixtures of nitrogen, water and acetylene in He have been studied.

The high pressure slit nozzle discharge  source

developed from H. Linnartz, D. Verdes, T. Speck(Rev. Sci. Instrum. 71 (2000) 1811)

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A TOF mass spectrum of a discharge through H20 in He. Large protonated clusterions of the form (H2O)nH+ with n as high as 56 are observed. For n=21 a stronger peak is found that corresponds to a magic number

References:

E. Witkowicz, H. Linnartz, C.A. de Lange, W. Ubachs,A. Sfounis, M. Massaouti, M. Velegrakis, “ Mass Spectrometric and Laser Spectroscopic Characterization of a Supersonic Planar Plasma Expansion”, Intern. J. of  Mass Spectrom. 232 (2004) 25