Abstract
A method for generating repetitive flash x rays using a compact cold-cathode triode in conjunction with a two-stage Marx pulser is described. This flash x-ray generator consisted of the following components: a high-voltage power supply with a maximum voltage of 100kV, an energy storage condenser with a capacity of 100nF, a modified two-stage Marx pulser with a capacity during main discharge of 425pF, a turbo molecular pump, a trigger resistor of 3kΩ, and a flash x-ray tube. The two ceramic condensers were charged from 50 to 70kV, and the output voltages from the high-voltage pulser were about 1.8 times the charged voltages. The x-ray tube was of the triode type which was connected to the turbo molecular pump with a pressure of 6.7x10-4Pa and consisted of the following major devices: a rod-shaped long anode tip made of tungsten, a ring-shaped trigger electrode made of brass, a cylinder-shaped cathode electrode made of graphite, and a tube body made of acrylate resin. The durations of the flash x-ray pulses were about ips, and the x-ray intensity with a charged voltage of 70kV was about 320nC/kg at 0.5m per pulse. The repetitive frequency was less than 50Hz, and the maximum size of the focal spot was equivalent to the anode diameter of 3.0mm.
