Study of plasma formation in a planar type ion diode with self-magnetic isolation

Abstract

One of the sources of high-power ion beams is an ion diode with isolation by external or self-magnetic field. Due to the simplicity and reliability of the design, this type of diodes is widely used in applied research. The explosive plasma generation on the anode surface under a bipolar voltage pulse is accompanied by a loss of the electron current from the anode-cathode region of the diode. The electron current characteristics depending on the operation mode of diode and the energy supplied are presented. Investigation of the cathode emission surface and distribution of the ion current density at the output of the diode along the anode surface were carried out. The ion current density reaches 15-25 A/cm2 at the outer edge of the anode, and 5-8 A/cm2 – in the central region. The area of emission surface of the anode is approximately 25-30% of the total anode area. Electron loss current in the matching mode of diode reaches 6.5 kA.