Abstract: In an X-ray image intensifier tube, a casing for the protection from x-radiation from the X-ray image intensifier tube. The casing according to the present invention comprises a jacket of a thermoplastic material charged with a powder of a material that absorbs the x-radiation and a shielding from outside magnetic fields. The shielding is in contact with the jacket. The screen that absorbs the x radiation thus is at least partially formed of the jacket.

Abstract: An apparatus for electrically insulating viewing windows in an image intensifier tube is disclosed. The mechanical parts which are located close to the window are electrically insulated with the metal parts being held at a high voltage and electrically insulated on the outside of the image intensifier by an insulating screen. The insulating screen includes electrically conductive layer 36 and an insulating layer 37 which separates the metal parts 20, 26 from the conductive layer. The conductive layer also forms an equipotential layer which is opposite the metal parts and thereby "freezes" the distribution of the electrical lines of force in the insulating screen 35.

Abstract: A vacuum-tight envelope (601) having a terminal element (610) bearing the envelope's output window. An output screen (605) is glued to the inner face of the output window by a first glue (608) having the same refractive index as the output window. The envelope's terminal element is made unitary with a (611) of the envelope by vacuum-tight mounting (609). An optional anti-reflection coating (674) may be deposited directly onto the external face of the output window.

Abstract: According to the invention, said jacket has an input port integral with a central ferrous alloy body, which is made from an alloy of aluminium and magnesium of series 5000. This input port is fitted into an aluminium part of series 1000, to which it is welded. The aluminium part is brazed to the central body by aluminium-silicon or aluminium-silicon-magnesium eutectic brazing.