GB449244A - Improvements in or relating to fluorescent screens for use with x-rays - Google Patents

Abstract

449,244. Fluorescent screens. RENWICK, F. F., 6, Reed Pond Walk, Gidea Park, Essex. Oct. 20, 1934, Nos. 30131/34,34590/34, and 1659/35. Drawings to Specification. [Class 98 (i)] An intensifying or viewing screen for X-ray use comprises a layer of a fluorescent zinc compound on a support having at or near its surface a layer containing a metal having an atomic number between 42 and 58 inclusive, the secondary radiations from which increase the fluorescence. The fluorescent material may be zinc sulphide or silicate, or zinc cadmium sulphide, and may be deposited in known manner by coating on a temporary support a suspension of the material in a binder such as collodion, and transferring the cast layer to its final support. This support may consist wholly of metal foil or sheet, or it may comprise a backing of metal (e.g. iron, copper, or zinc) or of a non-metallic substance (e.g. paper, card, or celluloid) to which is attached a metallic foil, or on which a metallic coating is deposited. The fluorescent layer may be applied directly on the metal foil or coating, or upon an intermediate non-metallic reflecting layer as of white paper. The metal, which may be chosen for its reflecting property, is preferably palladium, silver, cadmium, indium, tin, antimony or tellurium. Alloys of one or more metals of the class specified may be used, e.g. lead and tin; tin and cadmium ; cadmium, antimony and tin ; tin, antimony and lead ; or alloys of tin, cadmium and antimony with metals of lower atomic number, e.g. copper, nickel, zinc, or aluminium. The Provisional Specifications refer also to a fluorescent layer with a backing consisting of nickel or chromium or comprising a metal of higher atomic number than zinc.