Abstract: Ionic salts containing minor amounts of an activator and useful as scintillation phosphors are formed by extrusion of a macrocrystal of either a single crystal or a melt-grown multiple crystal ingot at a temperature below its melting point and under sufficient pressure to form a fully dense, homogeneous polycrystalline mass, the scintillation properties of which are essentially the same as, or better than, those of the original macrocrystal.

Abstract: A method is disclosed for hot press-forging a normally frangible optically integral crystalline mass ("optical body") in a closed die, by directly pressing a surface of the mass while it is peripherally surrounded by a crystal powder the amount of which is computed from the deformation ratio desired and the geometry of the die. The crystal powder is compacted by the non-uniformly directed forces transmitted to it by the optical body, and eventually the crystal powder is sufficiently dense so as dynamically to constrain the optical body at its peripheral surface. The dynamic constraint of the optical body while it is being forged is effected in such a way as to permit deformation of the optical body without fracturing it, and, without affecting its optical integrity.

Abstract: A method is disclosed for hot press-forging a normally frangible optically integral crystalline mass ("optical body") in a closed die, by directly pressing a surface of the mass while it is peripherally surrounded by a crystal powder the amount of which is computed from the deformation ratio desired and the geometry of the die. The crystal powder is compacted by the nonuniformly directed forces transmitted to it by the optical body, and eventually the crystal powder is sufficiently dense so as dynamically to constrain the optical body at its peripheral surface. The dynamic constraint of the optical body while it is being forged is effected in such a way as to permit deformation of the optical body without fracturing it, and, without affecting its optical integrity.

Abstract: A polycrystalline shaped article useful as a light-transmitting body or scintillation phosphor is formed from an essentially moncrystalline melt-grown macrocrystal ingot by pressing the ingot between opposed surfaces with no radial restraint, at a temperature below its melting point and under sufficient pressure to transform the ingot, in situ, into a fully dense, homogeneous, polycrystalline mass of unrestricted width.A polycrystalline shaped article useful as a light-transmitting and/or light-generating body may also be formed from a fully dense, homogeneous, optically integral polycrystalline mass by pressing the polycrystalline mass between opposed surfaces with no radial constraint, at a temperature below its melting point, but greater than one-half its melting point measured in degrees centigrade, under sufficient pressure to form a relatively larger polycrystalline mass of lesser height.

Abstract: A hot-pressed optical body which is free from absorption bands due to carbon dioxide, water, hydroxyl ion and acid fluorides in the ultraviolet, visible and near-infrared wavelength regions. Typically, the optical body is formed from a powder of an alkaline earth metal fluoride, alkali metal fluoride, or rare earth metal fluoride. One or more absorption bands due to a single impurity may be reduced or eliminated, or bands due to plural impurities may be reduced or eliminated sequentially, or simultaneously. The optical body is made by flowing a reactive, reducing gas, optionally, in combination with hydrogen fluoride gas, directly into the die cavity containing a pressable ionic fluoride powder, and either hot-pressing or extruding the powder.

Abstract: A hot-pressed optical body is disclosed which is free from absorption bands due to carbon dioxide, water, hydroxyl ion and acid fluorides in the ultraviolet, visible and near-infrared wavelength regions. Typically, the optical body is formed from a powder of an alkaline earth metal fluoride, alkali metal fluoride, or rare earth metal fluoride. One or more absorption bands due to a single impurity may be reduced or eliminated, or bands due to plural impurities may be reduced or eliminated sequentially, or simultaneously. The optical body is made by flowing a reactive, reducing gas, optionally, in combination with hydrogen fluoride gas, directly into the die cavity containing a pressable powder, and either hot-pressing or extruding the powder.

Abstract: A polycrystalline shaped article useful as a light-transmitting body or scintillation phosphor is formed from an essentially monocrystalline melt-grown macrocrystal ingot by pressing the ingot between opposed surfaces with no radial restraint, at a temperature below its melting point and under sufficient pressure to transform the ingot, in situ, into a fully dense, homogeneous, polycrystalline mass of unrestricted width.A polycrystalline shaped article useful as a light-transmitting and/or light-generating body may also be formed from a fully dense, homogeneous, optically integral polycrystalline mass by pressing the polycrystalline mass between opposed surfaces with no radial constraint, at a temperature below its melting point, but greater than one-half its melting point measured in degrees centigrade, under sufficient pressure to form a relatively larger polycrystalline mass of lesser height.