Repetitive electron beam source for high power microwave experiments

Summary form only given. A compact pulse transformer has been developed to operate at /spl sim/1 Hz, producing a 100 kV, 250 ns pulse. The output pulse has a /spl plusmn/1% flat top for 120 ns. This pulse is coupled to an electron beam diode which uses a ferroelectric ceramic disk as the source of a high-current-density electron beam. A portion of the pulse (/spl sim/2 kV) is applied across the ferroelectric, causing a rapid change in the polarization state. This change results in the emission of a high-density electron cloud into an accelerating diode gap. The accelerating pulse is applied across the diode gap and the electron beam is extracted into a cylindrical drift tube. The diode gap is adjusted between 1-10 mm and the anode potential is varied from 0-500 V. The emitted current is measured as a function of these parameters. Current densities of 70 A/cm/sup 2/ have been measured. The Child-Langmuir current density, for 500 V applied across a 4 mm gap, is 0.2 A/cm/sup 2/.