Development of an intense pulsed metallic ion beam source

Intense pulse metallic ion beams (Al⁺, Cu⁺, and Pb⁺) were produced by a magnetically insulated ion diode having a metal anode. Metal ion plasmas on the anode could be generated through enhanced electron bombardment by using a radial cathode. The energy, current density, and duration time of the lead ion beam were 30~140 keV, ~7.5 A/cm² (total ion current ⩾0.5 kA), and 800 ns, respectively. The ion current density exceeded the space-charge-limited current by a factor of 50. The lead ions in the first-to-sixth states of ionization were detected by a Thomson-parabola ion-spectrometer together with light loss, such as C⁺ and O ⁺. The ratio of the ion current of heavy metals to the total ion current was measured using a magnetic mass analyzer with a charge collector. The ratio was about 90% for a lead ion beam and 20~50% for Al and Cu ion beams