A compact low-voltage flash X-Ray tube

We describe the construction of a compact, low voltage flash X-ray tube. The device is powered by a small 25 kV, 3300 pF capacitor. Its design is of the vacuum spark configuration with a hollow cathode. The discharge is triggered by a low energy spark behind the hollow cathode; and the triggering spark is also powered by the main capacitor discharge. A 12 k� ballast resistor is connected to this auxiliary spark circuit to limit its current. The flash X-ray tube has been operated in air at pressures ranging from 10-1 to 10-4 mbar. At a charging voltage of 25 kV, the flash X-ray tube is able to produce X-ray pulses of several kilowatts in power