Patent ID: 8761344

Claim:
An x-ray tube, comprising: a. an electrically insulative cylinder; b. an anode disposed at one end of the insulative cylinder, the anode including a target which is configured to emit x-rays in response to electrons impinging upon the target; c. a cathode disposed at an opposing end of the insulative cylinder from the anode, the cathode including an electron emitter; d. a primary optic, comprising a cavity in the cathode, having an open end facing the electron emitter, and disposed on an opposite side of the electron emitter from the anode; e. an operating range of 15 kilovolts to 40 kilovolts between the cathode and the anode; f. an overall diameter, defined as a largest diameter of the x-ray tube anode, cathode, and insulative cylinder, being less than 0.6 inches; g. a cylindrical, electrically conductive electron optic divergent lens, attached to the anode and electrically connected to the anode, and having a far end extending from the anode towards the cathode; h. a cylindrical, electrically conductive electron optic convergent lens, attached to and surrounding the cathode and electrically connected to the cathode, and having a far end extending from the cathode towards the anode; i. an electron flight distance, from the electron emitter to the target, of less than 0.8 inches; j. a maximum voltage standoff length, from the far end of the divergent lens to the far end of the convergent lens, being less than 0.25 inches; k. an insulative cylinder length from closest contact with the cathode to closest contact with the anode being less than 0.7 inches; and l. a direct line of sight between all points on the electron emitter through a central portion of the convergent lens, through a central portion of the divergent lens, to the target.