Ion-beam-induced vacuum breakdown phenomena studied by emission spectroscopy

The impact of ion beams with an energy of keV on electrodes can induce microdischarges or dielectric breakdown, constituting a primary constraint on operational stability in vacuum systems. In this paper, the phenomenon of vacuum breakdown induced by 10 keV Cu ion beam bombardment on the surface of a hydrogen-containing metal electrode is studied. Utilizing spatiotemporally resolved emission spectroscopy, we capture (i) time-gated luminescence profiles during breakdown events and (ii) spectrally resolved emission maps of the electrode interface, which reveal transient desorption dynamics and spatiotemporal evolution of ionic species. Through mechanistic interpretation of these diagnostics, we elucidate the fundamental physical processes of vacuum breakdown induced by ion beam bombardment, and provide support for further understanding of the physical mechanism of breakdown induced by ion beam bombardment.