An investigation into the mechanism of pseudospark producing metal ion beams

A multiplate pseudospark chamber, whose electrodes were fabricated with dif ferent metal materials, was designed and tested as a metal ion source. The ion beam implantation combined with Rutherford backscattering (RBS) measure ment was used to understand whether these ion beams come from the anode pla sma or the cathode plasma. The RBS measurements have demonstrated the follo wing results: (1) pseudospark produced metal ion beams mainly consist of io ns from the cathode materials; (2) the ion beam current increases rapidly w ith the pseudospark discharge voltage first and then saturates; and (3) the energy of the extracted metal ions is much less than the voltage between t he anode and the cathode, therefore the high discharge voltage does not cor respond to the high ion energy. A possible mechanism of pseudospark produci ng metal ion beams is discussed. (C) 2000 American Institute of Physics. [S 0034-6748(00)64902-X].