Plasma-immersion formation of high-intensity gaseous ion beams

The symbiosis of plasma-immersion extraction of ions and their subsequent ballistic focusing in the hemisphere geometry of the focusing system was used to form a high intensity nitrogen, argon, and hydrogen ion beams. The gas-discharge plasma was formed using a hot-cathode-arc discharge source. The regularities of the formation of high-intensity ion beams of various gases from according to the pressures of the working gases, the plasma density depending dependence on the bias potential amplitudes in the range of 0.9-2.4 kV, frequencies in the range of 10-100 kHz and pulse durations in the range of 2-80 ps were investigated. The possibility of the stable forming of axially symmetric gas ion beams with a current density of up to hundreds of mA/cm(2) was shown. Nitrogen ion beams with a maximum current density of 0.7 A/cm(2) at the ion current of 0.6 A were obtained. Studies at nitrogen pressures in the range of 0.3-1.8 Pa revealed that a decrease in the gas pressure during the generation of a gas-discharge plasma caused a significant increase in the ion current amplitude at the collector.