X-ray tube

Abstract

An X-ray tube includes a metal portion in which an X-ray emission window is provided, an insulation valve which is joined to the metal portion and forms a vacuum region in cooperation with the metal portion, and a target and an electron gun which are accommodated in the vacuum region. The insulation valve has a low resistivity glass portion joined to the metal portion, and a high resistivity glass portion for fixing an anode including the target. A volume resistivity of a material forming the low resistivity glass portion is lower than a volume resistivity of a material forming the high resistivity glass portion. According to this configuration, electrification of the insulation valve is curbed, so that deterioration in withstand voltage ability of the insulation valve is curbed, and electric discharge caused by electrification is curbed.

Dependencies are inferred from the claim text.