Abstract: An X-ray image intensifier tube which includes a luminescent layer with an absorption material having a high absorption for secondary X-rays which are generated in the original luminescent material and which are intercepted to only a very small extent by the original luminescent material. The absorption material may be included in the layer of luminescent material in homogeneous form as well as in recesses in said layer. In addition to improved resolution, a higher efficiency can be achieved by ensuring that, upon interception of the secondary radiation, the absorption material generates luminescent or secondary radiation which is intercepted by the original luminescent material.

Abstract: A method of manufacturing light detection units which comprise a photocathode disposed on an entrance window, an electron detector including a semiconductor junction, and means which transmit the electrons from the photocathode to the electron detector including a perforated aperture plate disposed between the entrance window and the electron detector. The photocathode is formed on a surface of the entrance window after assembling the entrance window and electron detector to the means which transmit the electrons. Perforations in the aperture plate are covered with spherical shields while the photocathode is formed on the surface of the entrance window. The shields are then removed.