X-ray generator and method

An x-ray tube comprising:

• an envelope;
• an anode target rotatably mounted within the envelope;
• and
• a cathode and window assembly mounted within the envelope and spaced relative to the anode, wherein the cathode and window assembly includes an electrically insulative ceramic base defining an x-ray transmissive window therethrough, a recess formed on a first side of the electrically insulative base adjacent to a peripheral portion of the x-ray transmissive window, a filamentary electrode received within the recess, a first metalized conductive surface formed on a surface of the recess on one side of the filamentary electrode, a second metalized conductive surface formed on a surface of the recess on an opposite side of the filamentary electrode relative to the first metalized conductive surface and substantially electrically isolated relative to the first metalized conductive surface, a first terminal electrically connected to the first metalized conductive surface, a second terminal electrically connected to the second metalized conductive surface, and a high voltage cable receptacle located on a second side of the electrically insulative ceramic base, wherein the ceramic base electrically insulates the high voltage cable receptacle from the filamentary electrode and metalized conductive surfaces, and at least one of an electron beam size, shape, and direction emitted by the filamentary electrode is controllable by controlling a voltage differential between the first and second metalized surfaces.