Abstract: An exit section of an X-ray image intensifier tube, including an the exit phosphor screen, exit window and basic optical system, is optimized so as to achieve a high light yield, low optical aberration and a high resolution. The exit window notably has a pre-compensation geometry for curvature of the image plane of the basic optical system, or the exit window an interference filter, or the exit phosphor layer contains a layer of a comparatively slow phosphor in addition to a layer of a customary phosphor in order to achieve noise-suppressing image integration.

Abstract: The separating layer between the luminescent layer and the photocathode of the entrance screen in an X-ray image intensifier tube is formed by a layer which has a suitable optical transmission, a suitable chemical inertia, a suitable tightness and a strongly bridging character and which is deposited by means of a plasma CVD technique, so that all requirements to be imposed on a separating layer can be satisfied without causing a substantial loss of efficiency. By variation of the material composition, measured across the thickness of the layer, an optimum optical transition can be realized between the luminescent layer and the photocathode.

Abstract: An anode of an X-ray tube, particularly for X-ray analysis, comprises at least two successive layers (7, 8 or 11, 10 or 13, 12) of anode material. A first layer (7, 11, 12) thereof consists mainly of an element having a comparatively low atomic number, such as scandium or chromium, while a second layer (8, 10, 13) consists mainly of an element having a comparatively high atomic number, such as molybdenum, tungsten or uranium. For the selection of a desired radiation spectrum, the tube voltage is selectively adjusted such that either or both layers are activated.

Abstract: In an X-ray tube, particularly for the detection of elements having a low atomic number by X-ray spectral analysis, an anode support (4) is on the target side provided with a layer (7) of scandium. The scandium layer is provided on the support by adhesion via an intermediate layer (8), preferably of chromium. In a reflection tube, the anode support for the intermediate layer and the scandium layer is preferably made of silver or copper. In a transmission tube, the scandium is provided on a beryllium disc which acts as intermediate layer and as an exit window (6).

Abstract: Disclosed is an X-ray tube for fluorescence analysis having an exit aperture which is closed by a window of non-uniform thickness. A thicker window portion is located at the side of the aperture remote from the anode and partly overlaps a thinner window plate. In an analysis apparatus, the thicker window portion is located in a portion of the window through which passes the radiation traversing a comparatively small distance between the anode and the specimen.