Abstract: A method of storing an image produced by x-ray exposure and releasing the stored image is disclosed. It is disclosed to expose an x-ray storage screen, comprised of an isotropic storage phosphor and a polymer coated on a support, to x-radiation of a first wavelength in an imagewise manner to store an image pattern in the storage screen. The image pattern is retrieved from the storage screen by exposing the storage screen to radiation of a second wavelength, thereby stimulating radiation of a third wavelength. The polymer has an index of refraction which matches the index of refraction of the phosphor at the second wavelength, and the support is non-reflective to radiation of the second wavelength.

Abstract: A pair of front and back intensifying screens is disclosed capable of providing a sharp imagewise exposure of a dual coated silver halide radiographic element to light when the screens are imagewise exposed to X radiation predominantly of an energy level below 40 keV. The front intensifying screen is comprised of a fluorescent layer having modulation transfer factors greater than those of reference curve A in FIG. 3 and capable of attenuating by 20 to 60 percent a reference X radiation exposure produced by a Mo target tube operated at 28 kVp with a three phase power supply, wherein the reference X radiation exposure passes through 0.03 mm of Mo and 4.5 cm of poly(methyl methacrylate) to reach the fluorescent layer mounted 25 cm from a Mo anode of the target tube and attenuation is measured 50 cm beyond the fluorescent layer. The back intensifying screen has modulation transfer factors greater than those of reference curve B in FIG.

Abstract: An x-ray intensifying screen comprises a support having thereon a fluorescent composition comprising:(a) from 50 to 90 percent by weight of a substantially isotropic phosphor which is excited by x-rays and substantially transparent to light emitted by said phosphor; and(b) from 10 to 50 percent by weight of a polymer having an index of refraction within 0.02 of the index of refraction of said phosphor over at least 80 percent of the emission spectrum of said phosphor, said support having an index of refraction up to or equal to 0.05 units higher than the index of refraction of said phosphor and having a reflection optical density of at least 1.7 to light emitted by said phosphor.The screen is highly transparent, and further exhibits improved contrast and resolution.

Abstract: A method for the recrystallization of activated rare-earth oxyhalide phosphors is disclosed. The method comprises recrystallizing the phosphor by firing a phosphor-flux mixture in an inert atmosphere. The phosphor-flux is substantially homogeneous and the flux contains substantially dehydrated magnesium halide. One particularly preferred phosphor made by the method is a lanthanum oxychloride phosphor coactivated with bismuth and ytterbium. This phosphor made by the present method has high speed and low afterglow.

Abstract: A lanthanide phosphate provides a contrast agent useful in radiographic contrast compositions and surgical elements. Radiographic imaging methods which employ this contrast agent and methods of making lanthanide phosphate-containing radiographic contrast compositions are also disclosed.

Abstract: Green-emitting x-ray intensifying screens which produce radiographs with improved visualization of objects having low x-ray contrast are disclosed. These screens contain an absorber which preferentially absorbs blue light, e.g., a yellow dye. A reflective support is used in particularly preferred embodiments.

Abstract: Phosphors which have a host matrix of yttrium oxide or a rare earth metal oxide and are activated by one or more rare earth metal activators are prepared by heating a mixture of salts of the host and activator metals (preferably this mixture is formed by co-precipitating the salts of the host and activator metals) at an elevated temperature in an oxygen-containing atmosphere to form the oxide phosphor, and subsequently heating the phosphor at an elevated temperature in a non-oxidizing atmosphere, which is free of halogenating agents, chalcogenating agents, or fluxes. The step of heating in a non-oxidizing atmosphere brings about a substantial increase in the X-ray speed of the phosphor, improves the stability of the phosphor to light, and increases the reflectance of the phosphor in the visible region of the spectrum. Phosphors prepared by use of this process are useful in the manufacture of X-ray intensifying screens.

Abstract: The disclosure relates to an apparatus and method for recording images on recording mediums which images correspond to high energy radiation patterns. A temporary storage medium, such as an infrared-stimulable phosphor or thermoluminescent material, is exposed to an incident pattern of high energy radiation. A time interval after exposure, a small area beam of long wave length radiation or heat scans the screen to release the stored energy as light. An appropriate sensor receives the light emitted by the screen and produces electrical energy in accordance with the light received. The information carried by the electrical energy is transformed into a recorded image by scanning an information storage medium with a light beam which is intensity modulated in accordance with the electrical energy. Although the invention can be used at any reproduction ratio, it is particularly usable in recording images representative of large format high energy patterns onto microfilm.