摘要:
In a method of preparing a storage phosphor or a scintillator layer on a support by vapor depositing from a crucible unit in a vapor deposition apparatus, while heating as phosphor or scintillator precursor raw materials a matrix component and an activator component or a precursor component thereof, said crucible unit comprises a bottom and surrounding side walls as a container for the said phosphor or scintillator precursor raw materials present in said crucible, said crucible is provided with an internal lid with perforations (5) and said crucible unit further comprises a chimney as part of the said crucible unit and a slit allowing molten, liquefied phosphor or scintillator precursor raw materials to escape in vaporized form under reduced pressure from said crucible unit in order to become deposited as a phosphor or scintillator layer onto said support; and at least one heating means (1) in the chimney (2) is positioned under a heat shield with a slit (3) and a slot outlet (3′), covering thereby said crucible unit and making part of said chimney (2), so that said heating means (1) cannot be observed when looking into the vaporization unit through said slot outlet (3′) from any point in the plane of the said support present as a vapor deposition target in the said vapor deposition apparatus and, while vaporizing said phosphor or scintillator precursor raw materials, a vapor cloud escapes from said slot outlet (3′) in the direction of the said support so that the ratio of the longest radius of the said vapor cloud versus the radius perpendicular thereto, when projected onto the phosphor or scintillator plate or panel from whatever an intersection through the said vapor cloud between slot outlet (3′) and support is at least 1.3, said intersection being taken parallel with the said support.
摘要:
In a photostimulable storage phosphor screen or panel wherein said screen comprises storage phosphor particles dispersed in a binder and wherein said particles have a particle size distribution having a d99 which is not more than 15 μm, said d99 expressing a grain size limit above which not more than 1% by weight of phosphor powder particles is present in said phosphor powder, its structure noise parameter DQE2rel exceeds a value of 0.70 and a ratio of d99 (expressed in μm) and DQE2rel is not more than 25:1, wherein DQE2rel is the ratio of the DQE2 obtained at a dose of 22 mR to the DQE2 obtained at a dose of 3 mR, as expressed in formula (I) DQE2rel=DQE2(22 mR))/DQE2(3 mR) (I) which is representative for an amount of screen-structure noise produced by said screen or panel in the complete spatial frequency range.
摘要:
In a photostimulable storage phosphor screen or panel wherein said screen comprises storage phosphor particles dispersed in a binder and wherein said particles have a particle size distribution having a d99 which is not more than 15 μm, said d99 expressing a grain size limit above which not more than 1% by weight of phosphor powder particles is present in said phosphor powder, its structure noise parameter DQE2rel exceeds a value of 0.70 and a ratio of d99 (expressed in μm) and DQE2rel is not more than 25:1, wherein DQE2rel is the ratio of the DQE2 obtained at a dose of 22 mR to the DQE2 obtained at a dose of 3 mR, as expressed in formula (I) DQE2rel=DQE2(22 mR))/DQE2(3 mR) (I) which is representative for an amount of screen-structure noise produced by said screen or panel in the complete spatial frequency range.
摘要:
A binderless storage phosphor screen with needle shaped crystals, wherein the phosphor is an alkalihalide phosphor and the needles show high [100] unit cell orientation in the plane of the screen.
摘要:
In a method of manufacturing a radiation image storage phosphor layer on a support layer, wherein said method comprises a vapor depositing step of raw materials of an alkali metal halide salt and a lanthanide dopant salt or a combination thereof in order to ensure vapor deposition of a binderless storage phosphor layer from one or more resistance-heated crucible(s) in a vapor deposition apparatus, wherein one or more shutter(s) are positioned between said crucible(s) and said support, at the time said vapor depositing step starts while opening said shutter(s), a start temperature is measured on and registered by means of a thermocouple, positioned close to the support at the side of said support where vapor becomes deposited in order to form said binderless storage phosphor layer, of less than 300° C., but not less than 100° C., and wherein at the time said vapor depositing step ends by closing a shutter, an end temperature as measured on and registered by means of a thermocouple, positioned close to the side of said support where vapor becomes deposited, is increasing not more than 90° C. between starting and ending said vapor depositing step.
摘要:
In a method of manufacturing a radiation image storage phosphor layer on a support layer, wherein said method comprises a vapor depositing step of raw materials of an alkali metal halide salt and a lanthanide dopant salt or a combination thereof in order to ensure vapor deposition of a binderless storage phosphor layer from one or more resistance-heated crucible(s) in a vapor deposition apparatus, wherein one or more shutters are positioned between said crucible(s) and said support, at the time said vapor depositing step starts while opening said shutter(s), a start temperature is measured on and registered by means of a thermocouple positioned close to the support at the back side of the support, opposite to the side of the support where vapor becomes deposited in order to form said binderless storage phosphor layer, of less than 250° C., but not less than 100° C., when an additional heating is applied.
摘要:
In a radiation image phosphor or scintillator panel having as a layer arrangement of consecutive layers upon a support layer or a support, a phosphor or scintillator layer comprising needle-shaped phosphor or scintillator crystals, and a protective layer, the said support layer is a polished pure titanium sheet or titanium alloy sheet, or the said support comprises a polished pure titanium layer or titanium alloy layer.
摘要:
In a method of preparing a storage phosphor panel having a phosphor layer coated onto a dedicate substrate by vapor depositing raw phosphor precursor materials comprising a matrix component,an activator component and/or a combination thereof from one or more crucible unit(s) in a vapor deposition apparatus, wherein said crucible unit comprises a crucible container and a vaporization chimney; said method comprises the steps of (1) adding said raw phosphor precursor materials to said crucible unit, and (2) vapor depositing a phosphor layer from said raw phosphor precursor materials, wherein vapor depositing proceeds at an increased temperature in the crucible unit, said temperature exceeding the melting temperature of said matrix raw material with more than 70° C.; wherein an “activator coating weight number” for said phosphor layer reaches a value of at least 7,000; said “activator coating weight number” being defined herein.
摘要:
A binderless storage phosphor screen comprises a vacuum deposited CsBr:Eu phosphor layer on a support, wherein the support includes a layer of amorphous carbon and optionally one or more auxilliary layers.
摘要:
In a method of consecutively manufacturing a set of at least 5 storage phosphor plates by a vapor deposition process in one and the same vapor deposition apparatus, in said apparatus, before starting each vaporization, refractory material surfaces are brought into contact, in a crucible unit thereof, with liquefied raw materials of a matrix component and an activator component, a phosphor precursor component or a combination thereof, wherein deviations in speed from one plate to another within said set of storage phosphor plates are less than 15%, said deviations being expressed as a variation coefficient defined by following formula (SAL % dev/SAL % av)×100, provided that SAL % av stands for an averaged speed within average speeds over each of said storage phosphor plate surfaces within said set and that SAL % dev stands for a standard deviation of averaged speeds obtained from each phosphor plate within said set, wherein a step of increasing said refractory material surfaces is included by adding to said crucible unit, before starting vaporization in the manufacturing of each of said plates in said set, refractory particles selected from the group consisting of a powder, crystalline particles, amorphous particles, spheres, bars, sticks, ingots and curls or a combination thereof.