Fundamental Studies for the Long-Duration Flash X-ray Generator for Biomedical Radiography

Abstract

The fundamental studies for the long-duration flash x-ray generator utilizing a cold cathode radiation tube for biomedical radiography are described. This generator consisted of the following components: a high-voltage power supply, a high-voltage coaxial oil coondenser of 0.2μF-100kV, a vacuum pump, a trigger system for the cathode, and an x-ray tube with a set of graphite cathodes. When trigger currents flowed across cathode electrodes, the main discharge for producing flash x-rays was generated. The x-ray output was a single pulse and its pulse width was about 5.0μs. The x-ray pulse height and the time integrated intensity increased when the condeser charging voltage was increased, and the intensity was less than 2.0μC/kg at 1m per pulse. The x-ray quality became hard according to increases in the charging voltage and to the insertion of metal filters. The effective focal spot size was primarily determined by the diameter of anode tip and was less than 3.0mm in diameter.