An investigation into the mechanism of pseudospark producing metal ion beams

A multiplate pseudospark chamber, whose electrodes were fabricated with different metal materials, was designed and tested as a metal ion source. The ion beam implantation combined with Rutherford backscattering (RBS) measurement was used to understand whether these ion beams come from the anode plasma or the cathode plasma. The RBS measurements have demonstrated the following results: (1) pseudospark produced metal ion beams mainly consist of ions from the cathode materials; (2) the ion beam current increases rapidly with the pseudospark discharge voltage first and then saturates; and (3) the energy of the extracted metal ions is much less than the voltage between the anode and the cathode, therefore the high discharge voltage does not correspond to the high ion energy. A possible mechanism of pseudospark producing metal ion beams is discussed.