Abstract: Diode for providing X-rays. A diode for generating X-rays is adapted for connection to a source of high electrical energy with the diode having a first end from which the X-rays are emitted, a second end, and axis extending between the ends. The diode includes a ring cathode connected to the electron source and an intermediate anode spaced from the cathode with at least a portion of this anode being disposed between the ring cathode and the diode first end. The intermediate anode decelerates electrons to cause the generation of X-rays emitted from the diode first end. The diode also includes an intermediate cathode disposed radially outwardly of the intermediate anode and connected to this anode. The diode further includes an inverse anode spaced from the intermediate cathode and positioned radially outwardly of the intermediate cathode and between the intermediate cathode and between the intermediate cathode and the diode second end.