Indirectly heated cathode, especially for X-ray tube

摘要

The cathode includes a surface area (1) of an electron emission body (2) which is heated by a heating element (3) arranged in a distance behind it. Electrons leaving the heating element are accelerated onto the rear of the surface area through an electric field produced by an acceleration voltage applied between the heating element and the electron emission surface area. The electron emission body (2) is formed like a pot and comprises a short mantle (4). The mantle height is preferably between 10 to 200 percent of the diameter and/or the width of the electron emission surface area.