X-RAY TUBE HAVING AN INTERNAL WINDOW SHIELD

摘要

The filament for the emission of the electrons in an X-ray tube inevitably evaporates gradually during operation of the tube. Depending on the location of the filament in the tube, the metal vapor thus released is deposited on the X-ray window of the tube. Consequently, the transmission of the X-ray tube window gradually decreases in the course of the service life of the tube. In order to counteract the deposition of filament material, an edge structure is provided on the inner side of the window; this structure comprises edges which extend perpendicularly to the window surface, and is preferably a honeycomb structure with hexagonal cells. The height of the edges is chosen so that, viewed from the filament, the edge structure forms a shadow zone for the entire X-ray window, so that the metal vapor is deposited on the structure instead of on the window.