In a rotating anode tube, the anode target disc rotates on a highly specialized ball bearing system. The target is subjected to a focused stream of electrons emitting from the cathode and accelerated by a high potential difference between the target disc and the cathode. When the electron beam hits the anode, it produces the X-ray beam. The cathode provides a controlled source of electrons and the filament is a constructed tungsten wire coil of precise pitch and length. A motor rotates the anode disc at a high speed up to 10,000 rpm and to temperatures of 2000° C. The anode assembly is mounted on bearings and actually forms the rotor of the electric motor. The disc has a tungsten rhenium target area and faced onto a molybdenum disc. The disc is cooled by radiation to the glass then oil.