Generation of high-current pulses by a magnetized squeezed electron beam

Abstract

The space charge limited current of an electron beam generated in a magnetically insulated foil-less diode by a cylindrical or hollow cathode and injected into a cylindrical drift tube depends on the energy of the electrons and on the ratio of the beam radius to the tube radius. When this beam drifts into a tube of larger radius, it exceeds the corresponding space charge limit. This leads to the formation of a virtual cathode and to the reduction of the energy of the beam. The latter is known as a squeezed beam state. When the cylindrical tube consists of more segments of different radii and lengths, the dynamics of the beam can be manipulated. We propose a simple configuration resulting in the production of a high-frequency periodic train of high-current electron beam pulses.