The gadolinium plasma flash x-ray generator is useful for performing high-speed enhanced K-edge angiography using
cone beams because K-series characteristic x-rays from the gadolinium target are absorbed effectively by iodine-based
contrast media. In the flash x-ray generator, a 150 nF condenser is charged up to 80 kV by a power supply, and flash
x-rays are produced by the discharging. The x-ray tube is a demountable cold-cathode diode, and the turbomolecular
pump evacuates air from the tube with a pressure of approximately 1 mPa. Since the electric circuit of the high-voltage
pulse generator employs a cable transmission line, the high-voltage pulse generator produces twice the potential of the
condenser charging voltage. At a charging voltage of 80 kV, the estimated maximum tube voltage and current are
approximately 160 kV and 40 kA, respectively. When the charging voltage was increased, the K-series characteristic
x-ray intensities of gadolinium increased. Bremsstrahlung x-ray intensity rate decreased with increasing the charging
voltage, and clean K lines were produced with a charging voltage of 80 kV. The x-ray pulse widths were
approximately 100 ns, and the time-integrated x-ray intensity had a value of approximately 500 μGy at 1.0 m from the
x-ray source with a charging voltage of 80 kV. Angiography was performed using a filmless computed radiography
(CR) system and iodine-based contrast media. In the angiography of nonliving animals, we observed fine blood
vessels of approximately 100 μm with high contrasts.
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