Abstract
A hot-cathode flash x-ray generating system driven by an oscillation- type high-voltage pulser has been studied for testing an availability in the biomedical application.
The essential parts of the system are a negative high-voltage pu lser with a trigger device, an x-ray tube and a DC supplier for heating a filament of the tube. The high-voltage pulser is composed of an oscillation pulser with two ceramic condencers and a coil. A doubled high-voltage is provided by inverting a polarity of one of the two charged condensers connected in series by a trigger of air-gap spark.
In the present work, the tube voltage is nearly equal to the pulser output, even if the tube current flows in the x-ray tube. The tube voltage is, therefore, about 1.4 times the charged voltage and its maximum is about 100kV with the maximum tube current of 0.75A. An effective duration of the oscillating voltage is less than 7 ps and the repetition rate of the pulser output attains to about 100Hz. Under the charged voltage of -70kV, the maximum x -ray intensity is about 72.1 nc / kg per pulse at the distance of 0.5m, and the focus spot is of 3.0 x 4.0mm in size.
The values of floating capacity and resistivity are also estimated from the observed da mped oscillating from of the pulser output.
