Single-Flash X-ray Source Utilizing a Triode for Biomedical Radiography

Abstract

A high-intensity single-flash x-ray generator utilizing a triode is described. This generator was constructed in order to obtain the stable flash x-rays at the low operating voltage of about 50kV and consisted of the following components: a high-voltage power supply, a coaxial oil condenser of 100kV-200nF, a gas gap switch having a high-energy trigger device, a low-impedance coaxial transmission line, a turbo molecular pump, and a x-ray tube of the triode type. This generator may be used for condenser charging voltages of 40-100kV and the peak currents of 10-40kA. The pulse widths of the flash x-rays were almost constant and their values were about 300ns. The time integrated x-ray intensity varied according to the charging voltage, anodecathode (A-C) impedance, and the diameter of the anode rod and its maximum value was about 5 x 10^-6 C/kg at 1m per pulse. The effective focal spot was primarily determined by the diameter of the anode tip, and it ranged from 0.5 to 3.0 mm in diameter. The x-ray quality of flash xray source tended to become hard according to increases in the charging voltage and to increases in the A-C impedance.