Generation of an Intense Pulsed Aluminum Ion Beam by a Magnetically Insulated Ion Diode with Vacuum Arc Ion Source

Summary form only given. Intense pulsed heavy ion beams have a wide area of applications including nuclear fusion, materials processing, and plasma production. Pulsed ion beams are usually generated by a pulsed power ion diode with surface flashover ion source. However, in the diode the producible ion species and the purity of the beam are limited. To generate variety of ion species we have developed a new type of ion diode. In the diode a gas puff plasma gun and a vacuum arc plasma gun are used as ion source. A pulsed power generator of output voltage 200 kV, current 20 kA, pulse duration 100 ns is used to apply the acceleration voltage to the magnetically insulated acceleration gap of d_A-K = 10 mm. The plasma gun is placed 100 mm upstream from the acceleration gap. With gas puff plasma gun, nitrogen ion beam is successfully accelerated and ion current density more than 50 A/cm² has been obtained. The purity of the ion beam is evaluated by a Thomson parabola ion analyzer and found that > 85% of accelerated ions are nitrogen. To generate aluminum ion beam vacuum arc ion source has been developed. By the pulsed vacuum arc discharge between the coaxial electrodes, ion current density > 100 A/cm² has been observed at 100 mm downstream from the gun.