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Negative Ions in a Glow Discharge of Tetrafluoromethane
Author(s) -
Meichsner J.,
Poll H. U.,
Wickleder K. H.
Publication year - 1985
Publication title -
beiträge aus der plasmaphysik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.531
H-Index - 47
eISSN - 1521-3986
pISSN - 0005-8025
DOI - 10.1002/ctpp.19850250510
Subject(s) - langmuir probe , ion , plasma , glow discharge , electron density , chemistry , atomic physics , electrode , electron , electric discharge in gases , analytical chemistry (journal) , plasma diagnostics , chromatography , physics , organic chemistry , quantum mechanics , electrical engineering , engineering
The Langmuir — probe measurements in a CF 4 — glow discharge reveal a large number of negative ions (10 10 cm −3 ) in the plasma between the planar C‐electrodes. Under special conditions the density of them exceeds the electron density at several orders of magnitude and sustains a quasi — electron free plasma. The ratio depends on the residence time of the molecular gas in the discharge reactor. It is due to dissociative electron attachment to highly molecular gas components arising from the plasmachemical conversion of CF 4 . F − and CF 3 − are the most important negative ions.