X-ray tube

Abstract

An X-ray tube (1) according to the invention comprises a housing (2); an electron gun (3) that emits an electron beam (B) in the housing (2); and a target (4) that generates an X-ray beam (R) when the electron beam (B) strikes the target (4) in the housing (2). The electron gun (3) comprises a cathode (32) that emits electrons and a focusing electrode (34) that focuses the electrons as an electron beam (B) onto the target (4). The focusing electrode (34) has a tubular shape with an inner surface (51) and an outer surface (52). The inner surface (51) comprises a first region and a second region located on the target side with respect to the first region. The average roughness of the second region is lower than the average roughness of the first region.