1992 年 18 巻 3 号 p. 36-46
The fundamental studies for the repetitive pulsed (flash) x-ray generator as an ionization source are described. This generator consisted of the following essential components: a constant high-voltage power supply, an energy-storage condenser of 97 nF, a high-voltage pulser with a repetitive trigger device, a turbo molecular pump, and a flash x-ray tube. The x-ray tube was of a cold-cathode diode which was connected to a turbo molecular pump with a pressure of 6.7×10-4 Pa and was composed of the following major devices: a plate anode made from a copper foil of 100 μm in thickness, a pipe-shaped graphite cathode with a diameter of 10.0 mm, and a tube body made of polymethylmethacrylate. The high-voltage pulser employed polarity-inversion-type transmission line having two ceramic high-voltage condensers and a coil of 3.3 μH. The two condensers were charged from 50 to 70 kV by a power supply, and the electric charges in the condensers were discharged to the x-ray tube for generating flash x rays when the polarity of a condenser was changed after the triggering. The electrostatic capacity of each condenser was 850 pF, and the maximum output voltage from the high-voltage pulser was about －1.4 times the charged voltage. The maximum values of the cathode voltage (－1 times the tube voltage) and the tube current were about －80 kV and 0.3 kA, respectively. The pulse width ranged from 40 to 100 ns, and the x-ray intensity was less than 32 μC／kg at 22 mm per pulse. The maximum size of the x-ray source was equivalent to the anode diameter of 27 mm, and the repetition rate was less than 40 Hz.
