Crossed-field secondary emission electron source

A novel crossed-field secondary-emission (CFSE) electron source that is capable of producing high current tubular electron beams is described. This new electron source is based on the mechanism of secondary emission multiplication of electron current in a magnetron-like device having smooth cylindrical electrodes. The input electron current may be as low as a few mA. The multiplication process starts at the negative slope of an applied voltage pulse. After initiation, the current is extracted from the diode region with no regard to the voltage pulse shape and as a consequence, the CFSE electron source can operate in a long pulse mode. At the diode voltage of /spl sim/40 kV for a diode gap of /spl sim/6 mm, the output current reaches a value of more than 100A. A further increase of current up to 1 kA is feasible.