Mechanism of anomalous ion generation in vacuum arcs
G.A. Mesyats a
S.A. Barengol’ts b
a Lebedev Physical Institute, Russian Academy of Sciences, Leninsky prosp. 53, Moscow, 119991, Russian Federation
b Institute of Electrophysics, Ural Branch of the Russian Academy of Sciences, ul. Amundsena 106, Ekaterinburg, 620016, Russian Federation
A model for the generation of an ion flow in a vacuum arcs is proposed, based upon the analysis of electron processes. It is shown that the charge states and the velocities of directed motion of the ions result from cathode microsections being explosively destroyed by Joule heating with a high-density current. In this case, the ionization processes occur within a narrow (of the order of a micrometer) region near the cathode, and thereafter the ionic composition of the plasma remains unchanged. For arc currents of up to a kiloampere, a current increase simply increases the number of simultaneously operating ectons, thus explaining the weak experimental dependence of ion flow parameters on the vacuum arc current.