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Publication
Revisiting theoretical description of the retrograde motion of cathode spots of vacuum arcs
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Advisor(s)
Abstract(s)
A fresh attempt to develop a self-consistent descrip tion of the retrograde motion of cathode spots on volatile cathodes
is undertaken. Three potential mechanisms of effect of transversal
magnetic field on the distribution of parameters in the spot are
studied: the effect of magnetic field on hydrodynamics processes
in the spot, in particular, on the formation of liquid-metal
jet and the droplet detachment, and the effect of transversal
magnetic field over the motion of ions and emitted electrons
in the near-cathode space-charge sheath. It is found that for
typical conditions of cathode spots in vacuum arcs the effect
of magnetic field over the formation of liquid-metal jet and
the droplet detachment is negligible; the motion of the ions in
the near-cathode space-charge sheath is not disturbed; and the
motion of the emitted electrons is disturbed only marginally.
Thus, the above-mentioned potential mechanisms are hardly
relevant and the first-principle understanding is still missing.
A phenomenological description of the retrograde motion is
developed as an alternative. The description employs general
considerations without relying on specific assumptions and the
(only) unknown parameter can be determined from comparison
with the experiment.
Description
Keywords
Arc discharges Cathodes Plasma sheaths Vacuum arcs . Faculdade de Ciências Exatas e da Engenharia
Citation
Benilov, M. S., Kaufmann, H. T., Hartmann, W., & Benilova, L. G. (2019). Revisiting theoretical description of the retrograde motion of cathode spots of vacuum arcs. IEEE Transactions on Plasma Science, 47(8), 3434-3441. DOI: 10.1109/TPS.2019.2904866
Publisher
Institute of Electrical and Electronics Engineers