A panel shaped, proximity type, x-ray image intensifier tube for medical x-ray diagnostic use having all linear components and yet a high brightness gain, in the range of 500 to 20,000 cd-sec/m 2 -R, the tube being comprised of a rugged metallic tube envelope, an inwardly concave, iron, nickel, chromium alloy input window, a full size output display screen, a halide activated alkaline-halide scintillator photocathode screen suspended on insulators within the envelope and in between the input window and the output screen, and a high Z glass output window to reduce x-ray backscatter inside and outside of the tube The tube can be used in a direct view, photofluorographic mode, in a radiographic camera system and with a remote view TV system

Panel type X-ray image intensifier tube and radiographic camera system

Publisher Summary This chapter describes that an X-ray image intensifier (XRII) is a device that converts an incident X-ray pattern to yield a visible-light image of brightness, substantially higher than a simple phosphor screen. In most XRIIs, the final image is considerably smaller than the incident X-ray pattern that facilitates the coupling of optical lenses to transfer the image to the final image receptor such as video pickup, eye, cine film, and many more. The brightness gain is achieved in two ways: first, by increasing the number of light quanta generated from a given region of the X-ray pattern and second, by reducing the size of the final image so that the quanta is emitted from a smaller area. The chapter also discusses that in almost all XRIIs, the X-ray pattern is converted to a light pattern using a phosphor and the brightness of the light pattern is then intensified. Many systems employ electron-optical processes to provide the quantum gain, even though this requires additional stages of quantum conversion; the light from the input phosphor is converted to an electron image by a photoemitter that forms the cathode of an electron-optical system. After gaining energy by passing through an electrostatic field, the electrons are converted back into a light image in another phosphor.

X-Ray Image Intensifiers

A portable X-ray imaging system for small-format applications

A small rugged imaging X-ray spectrometer: A lixiscope with good energy resolution

Publisher Summary This chapter provides an overview of channel electron-multiplier plates in X-ray image intensification. Channel electron-multiplier plates have provided the means of achieving a very high electron gain in a small volume and would thus appear to be ideal for use in image intensifiers. The conventional type of X-ray image intensifier, which needs to have a large diameter to cover areas of interest in the human body, achieves its gain by electron optically demagnifying the image and accelerating the electrons by means of a potential difference of about 25 kV. This study investigates the possibility of making a proximity focused X-ray intensifier using a channel plate to provide the gain. This tube has a magnification of unity and can be viewed directly without the need of auxiliary viewing systems. The size of the tube is limited to 5" for ease of manufacture in the research laboratory although there is no fundamental limitation to the size. This chapter describes the manufacture and properties of the channel plates used, and then discusses the construction of the tube and the performance requirements. The results of measurements on some tubes are given, together with some photographs of the images produced.

D.L. Lamport

Papers

Channel Electron Multiplier Plates in X-Ray Image Intensification