Decay of vacuum arc plasma with composite CuCr cathodes after a discharge current break

The decay processes of a vacuum arc plasma after a discharge current break have been studied depending on the cathode elemental composition and the magnetic field induction. As the main methods of investigation, we used measurements of the ion current by a collector and the time-of-flight diagnostics of the mass-to-charge composition of ion fluxes from the decaying vacuum arc plasma. It is shown that the plasma generated with copper-chromium cathodes, after the vacuum arc current is interrupted, decays more slowly than when using a single-element copper cathode. The practical value of the results obtained is in the demonstration of the specific features of the decay processes in the vacuum arc plasma that develop after the discharge break in the conditions typical for operating vacuum interrupters. It is assumed that the use of copper-chromium composites as electrode materials in the presence of a magnetic field may affect the efficiency of interrupting high currents and recovery of the breakdown strength of vacuum interrupters.