Characteristics of Ion Beams Produced in a Plasma Focus Device

Abstract

The characteristics of the ion beams produced in a plasma focus device were studied. In the experiment, a Mather-type plasma focus device was used which was prefilled with H2 at 2.3 Torr. Ion species and their energy spectra were evaluated with a Thomson parabola spectrometer. The particle pinhole image was obtained with an aluminum filtered particle pinhole camera. The ion current density was measured with a biased ion collector. From the measurement, the proton beam energy was found to be distributed from 0.15 MeV to 2 MeV. The particle pinhole image of the proton beam with an energy of more than 1 MeV has spotlike patterns. The ion current density of 2400 A/cm2 with a pulse width of 50 ns was observed on the axis at z=260 mm from the top of the anode. The peak power brightness of the proton beams was evaluated to be 18 GW/cm2/sr/keV, and the total power brightness was evaluated to be 20 TW/cm2/sr.