X-ray tube target assembly with integral heat shields

摘要

A graphite-backed metallic x-ray tube target assembly has a rotary shaft which passes through the central opening of the annular graphite substrate and is secured to the metallic disk-shaped target. In order to protect the shaft from heat radiated from the graphite substrate, at least one tubular heat shield is brazed to the target and disposed between and separate from the inner wall of the annular graphite substrate and the outer peripheral surface of the shaft. For further protection, a tubular heat shielding member may be disposed inside the other heat shield, between the outer heat shield and the shaft. In order to minimize the heat conduction from the outer heat shield to the inner heat shielding member, they are mostly separated and attached to each other only along their bottom edges where they are tack-welded together at mutually separated positions such that the inner heat shielding member is supported entirely by the outer heat shield.