Experimental Study of a Compact Surface Flashover Ion Source

Compact ion sources are widely used in plasma thrusters, thin film deposition, ion implantation, and so on. This study fabricated a compact surface flashover ion source with titanium thin films deposited on alumina substrates as electrodes. The fabrication process, phase composition analysis, ion current and ion current distribution, and mass-to-charge composition of the compact surface flashover ion source are presented in this article. The phase composition analysis revealed that the phase composition of the electrodes was not affected after more than 200 discharges; however, the discharge changed the diffraction peak intensity ratio. A parallel-plate electrode and 9-tip probe array were used to measure the total ion current and ion current distribution. The experimental results confirm the excellent discharge stability of the ion source, and the uniformity of the ion current at different positions. By measuring the mass-to-charge composition, it was found that the main composition of ions was Ti
$^{\text {i}+}$
. In the initial discharge period, the dominant ion species were Ti3+ and Ti4+. At a later period, the dominant ion species were Ti1+ and Ti2+. The results can be useful in the development of novel compact ion sources.