Characteristics of the intense ion beams generated with the Point Pinch Diode

The characteristics of the intense ion beams generated with the Point Pinch Diode which consisted of a semispherical mesh cathode and a flat anode were investigated. From the experimental results, it was verified that the ion beam was divergently extracted, but the current density of the ion beam was high around a diode axis. Due to this divergence, the current density of the ion beam decreased from several tens of kilo-amperes per square centimeters in the diode to 10–30 A/cm² on a diode axis at 190 mm from the top of the cathode. From the time of flight method, it was made clear that the metallic ions (e.g. Cu⁵⁺) were contained in the ion beam as equally as the protons. Here the acceleration voltage for these ions was 350 kV.