X-Ray Rotating Anodes - graphite anodes

99 % of the energy utilized to generate an X-ray becomes lost heat and must be conveyed away. The burn spot on the edge of the anode is distributed through rapid rotation (3000-9000 rpm). A thin metal layer made of for example tungsten rhenium alloy is brazed onto the graphite anode. Graphite as a material is distinguished by its high thermal capacity, excellent thermal conductivity, radiation absorption and increasing strength at high temperatures when compared with purely metal anodes (e.g. tungsten or molybdenum). The rotating mass of the anode is considerably reduced, as the density of graphite is only 10% of that of tungsten.