Abstract: A planar, high voltage substrate, such as that used in an image intensification tube, is supported within the tube envelope by means of a plurality of electrically insulated rods which are arranged in the plane of the substrate, with each of the rods being perpendicularly attached at one end to the edge of the substrate and at the distal end to the tube envelope. In the preferred embodiment the rods are removably attached to the substrate, thereby allowing various substrates to be easily interchanged during the manufacture of the image intensification tube.

Abstract: Intensifier tubes for x-rays or low-light levels form an image of photoelectrons which is focused on a fluorescent viewing screen. Stray magnetic fields, including the earth's field, bend the electron trajectories and distort the image. Magnetic shielding has been used around the tube, leaving the image-receiving end open. Magnetic field leaking through the open end is reduced by extending the end of the shield around the image-receiving aperture inward and forward of the edge of the tube.