Theory of high-current diodes with large radii

A theory of high-current diodes with large radii is being developed. An attempts are made to specify the estimate of the diode current in the region of low voltages. A problem on field and current distribUtion for electron diode without the outer magnetic field is being solved. The diode behaviour in a strong maanetic field is also studied. A case when in interelectrode gap there are ions as well as electrons is considered. A stationary picture of strong focusing of electron beam under the action of ion emission from anode plasma is considered. The analytical solutions, obtained, can not substitute the numerical approach but make a considerable contribution into it. They present a clear idea of the physical mechanisms determining the diode operation