Intense ion beam generation in a diode with explosive emission cathode in self-magnetically insulated mode

This paper presents a review of experimental studies on pulsed intense ion beam generation in self-magnetically insulated diodes with an explosive emission cathode. The experiments were carried out with the TEMP-4M accelerator operating in double-pulse mode: the first pulse is of negative polarity (300-500 ns, 100-150 kV), and this is followed by a second pulse of positive polarity (150 ns, 250-300 kV). The ion beam energy density is 0.5-5 J/cm(2) depending on the diode geometry. We have developed a new spiral geometry of the diode. In a spiral diode it is possible to increase the efficiency from 5-9% (previously studied diodes) up to 20-25%. We conducted a study on shot-to-shot variation in the ion beam parameters. It was found that the standard deviation of the energy density does not exceed 11%, whilst the same variation for ion current density was 20-30%. Focusing properties of an ion beam have been significantly improved by using a metal shield on the grounded electrode. Use of the shield on the grounded electrode provides decrease in the beam divergence from 11 degrees to 7.5-8 degrees.