Abstract: The X-ray apparatus of the present invention comprises a metal cylindrical wall member having a longitudinal axis and opposite open ends. A pair of end members is positioned within the open ends of the wall member, at least one of the end members being an annular ceramic member having a central aperture therein and being sealed at its outer periphery to the wall member. An anode and a cathode are located within the wall member and high voltage leads are connected to the anode and cathode, at least one of these leads passing through the aperture in the ceramic member in a vacuum-tight manner to form a vacuum-tight envelope comprising the wall and end members. At least one connecting member is releasably attached to an end of the wall member adjacent the annular ceramic member thereby providing an axial releasable electrical connection with a high voltage lead.

Abstract: An X-ray tube including a cylindrical vacuum envelope at whose frontal or end surfaces are disposed the high voltage leads for the anode and the cathode. The vacuum envelope comprises a cylindrical metal member with at least one end surface face thereof being closed in a vacuum tight manner by means of an annular ceramic member with one of the high voltage leads, and possibly further leads, passing through the central opening of the annular member in a vacuum tight manner, so that the insulating path between the associated high voltage lead and the metal cylindrical member extends in a predominantly radial direction. Preferably the outer surface of the annular ceramic member forms an angle with a plane perpendicular to the longitudinal axis of the X-ray tube which angle is equal to or less than 45.degree., and more preferably equal to or less than 30.degree..