Mass-energy analysis of ions in the anode plasma created by high-current vacuum spark

The paper presents the results on charge and energy ion distribution of heavy species of plasma generated at the anode of vacuum discharge. Liquid metal Ga-In alloy was used both as the cathode and anode material. Using an electrical circuit with a relatively low impedance (~6 Ohm) and short inter-electrode gap (<;1 mm), relatively high current (~1 kA) was achieved in the discharge at the initial voltage of ~10 kV. With this, relatively high power density (>;10⁸ W/cm²) was applied to the anode during ~50 ns time period, generating a high-density anode plasma like at the electron-beam ablation. By means of HIDEN EQP analyzer, energy spectra analysis of separate ion charge state species of such ablation plasma was performed. Data obtained show the presence of highly ionized species (up to Z = 4). Ion energy was found to be proportional to the ion charge and increasing with the applied power density.