X-ray source

Abstract

An X-ray source with a cathode formed as a cylindrical electrode having a hollow central anode tube on its axis, with a grid surrounding the anode and interposed between the anode and cathode. The central anode tube is hollow and filled with a working medium. A high negative voltage is applied to the cathode, but the flow of electrons to the anode is blocked by the grid which is held near cathode potential. After a space charge is created at the grid by electrons from the cathode, a very short pulse to ground is applied to one end of the grid, yielding a relativistic wave of potential which propagates along the axial length of the grid. This wave of potential releases the electrons from the cathode, which flow directly to the anode. The impingement of the electrons on the tubular anode produces X-rays from the interior surface of the anode tube. These X-rays, together with the impinging electrons, pump the working medium along the length of the anode, causing a population inversion leading to the release of coherent X-rays in a wave synchronized with the propagating grid potential which exits the structure at the far end of the anode. The X-ray source may consist of identical units coupled together in series to provide a high power X-ray beam, and may be configured in other than cylindrical shapes depending on the output desired.