Abstract
The paper considers the main physical processes that determine flows of charged particles onto a negative metal electrode immersed in a fully ionized isotropic plasma. Equations are found describing the charged particle motion in the plasma both near the metal electrode under a constant negative potential \({{\Psi }_{0}}\) and far from it. The charged particle flows from the plasma to the electrode in the charge separation region near the electrode surface are calculated for large ratios of the electrode electric potential \({{\Psi }_{0}}\) to the plasma electron temperature \({{T}_{e}}\) : \(e{{\Psi }_{0}}{\text{/}}{{T}_{e}} \gg 1\) . The ion and electron current densities from the plasma to the electrode are calculated. It is shown that, in the specific case of interaction of a negative titanium electrode with a natural oxide film about 10 nm thick with a pulsed plasma with a density \({{n}_{i}} = {{10}^{{13}}}\) cm–3, as a result of charge transfer to the film surface by the ion flow from the plasma, electric voltages of about 6 V and a corresponding strong electric field of about 6 MV/cm arise inside the film over characteristic times of 5–8 μs. Such a strong electric field leads to electrical breakdown of the thin film and excitation of microplasma discharges on titanium. A reduction in the plasma density significantly reduces the probability of excitation of microplasma discharges on the surface of the metal electrode.
