A million-volt resonant-cavity X-ray tube

A very compact high-voltage X-ray tube is described, in which the accelerating voltage is developed in a resonant cavity excited by a high-power magnetron operating at a wavelength of 25 cm. A mean current of 70 ¿A has been obtained at a peak voltage of 1.1 MV. Two points of interest are that the focal spot is very small (approximately ¿ mm in diameter) and that, because the output is pulsed, the tube may be used as a stroboscope for the radiography of moving machinery. The limitations which apply to this method of acceleration are discussed.