Monochromatic flash x-ray generator utilizing a disk-cathode silver tube

The high-voltage condensers in a polarity-inversion two-stage Marx surge generator are charged from –50 to –70 kV by a power supply, and the electric charges in the condensers are discharged to an x-ray tube after closing gap switches in the surge generator with a trigger device. The x-ray tube is a demountable diode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Clean silver K lines are produced using a 30-µm-thick palladium filter, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. At a charging voltage of –70 kV, the instantaneous tube voltage and current are 90 kV and 0.8 kA, respectively. The x-ray pulse widths are approximately 80 ns, and the instantaneous number of generator-produced K photons is approximately 4×107photons/cm2 per pulse at 0.3 m from the source 3.0 mm in diameter.