HIGH SPEED POWER AMPLIFIER USING AN ELECTRON SWITCHED P-N JUNCTION

Several 20 KV electron beam multiplier tubes were made to deliver 5 ampere positive pulses of 1 microsecond in duration at 1,000 to 50,000 pps. The diode voltages ranged from 600 to 1,400 volts (saturation point). The current gain was in the range of 2,000 to 4,700. The rise time of the pulse was measured at 10 nanoseconds with an input signal of 10 nanoseconds. A modified standard TV electron gun was used to generate electron-hale pairs in the diodes. Grid cutoff averages 28 volts, and the beam current is approximately 1.6 mA at 50 volts input. Initially some deterioration problems were encountered in the diode when the duty cycle is raised beyond approximately 5%. However the devices fabricated toward the end of this contract do operate at a 10% duty cycle with no apparent deterioration. The gain of the devices made thus far were somewhat below the calculated theoretical 5,000. It is felt that operation at 10% duty cycle and a somewhat higher current are feasible with more effort on diode development. (Author)