A process for detecting oil or lubricant contamination in the production of an article by adding a Stokes-shifting taggant to an oil or lubricant of a machine utilized to produce the article or a component thereof, irradiating the articles produced with a first wavelength of radiation, and monitoring the articles for emission of radiation at a second wavelength. The taggant can be in the form of a composition containing a Stokes-shifting taggant, which absorbs radiation at a first wavelength and emits radiation at a second wavelength, different from said first wavelength, dissolved or dispersed in an oil or lubricant.

A process for detecting oil or lubricant contamination in the production of an article by adding a Stokes-shifting taggant to an oil or lubricant of a machine utilized to produce the article or a component thereof, irradiating the articles produced with a first wavelength of radiation, and monitoring the articles for emission of radiation at a second wavelength. The taggant can be in the form of a composition containing a Stokes-shifting taggant, which absorbs radiation at a first wavelength and emits radiation at a second wavelength, different from said first wavelength, dissolved or dispersed in an oil or lubricant.

A phosphor of an embodiment has a composition represented by a composition formula: Na.sub.xRM.sub.yS.sub.zO.sub.a, where R represents at least one element selected from the group consisting of Y, La, Gd, and Lu, M represents at least one element selected from the group consisting of Bi, Ce, Eu, and Pr, x is an atomic ratio satisfying 0.93<x<1.07, y is an atomic ratio satisfying 0.00002<y<0.01, z is an atomic ratio satisfying 1.9<z<2.1, and a is an atomic ratio satisfying 0.001<a<0.05.

A scintillator array includes a first scintillator element, a second scintillator element, and a reflector provided between the first and second scintillator elements and having a width of 80 m or less therebetween. Each scintillator element includes a polycrystal containing a rare earth oxysulfide phosphor, the polycrystal having a radiation incident surface of 1 mm or less1 mm or less in area. An average crystal grain diameter of the polycrystal is not less than 5 m nor more than 30 m, the average crystal grain diameter being defined by an average intercept length of crystal grains in an observation image of the polycrystal with a scanning electron microscope. A maximum length or a maximum diameter of defects on the polycrystal is 40 m or less.

A scintillator comprises a sintered body having a volume of 1 mm.sup.3 or less. The sintered body includes a crystal region of a rare earth oxysulfide. The number of polycrystal bodies each having a different composition from that of the crystal region is 200 or less per a unit area of 100 m100 m of a cross section of the sintered body.

An object of the present invention is to provide a radiological image conversion screen where the flexibility and the storage stability of the radiological image conversion screen are sufficiently kept without phthalic acid ester while conventional sensitivity and sharpness being maintained, and another object thereof is to provide a radiological image conversion screen where a plasticizer in a phosphor layer is suppressed from volatilization and from transfer to other layers and/or films. The objects are solved by a radiological image conversion screen comprising a support substrate and a phosphor layer stacked on the support substrate, wherein the phosphor layer comprises phosphor particles, a polyvinyl acetal resin, and a carboxylic acid ester having an ether group.

A scintillator panel includes at least one light emitting layer and at least one non-light emitting layer laminated, wherein the light emitting layer contains phosphor particles, and when the thickness of the light emitting layer is represented by A, a relationship among a cumulative 50% particle diameter D.sub.50 of the phosphor particles based on volume average, a cumulative 90% particle diameter D.sub.90 of the phosphor particles based on volume average, and the thickness A satisfies,
D.sub.50<A and D.sub.90<2A.

The present invention provides a gadolinium oxysulfide sintered body having a high light output. The problem is resolved by a gadolinium oxysulfide sintered body in which the ratio of the light transmittance T.sub.410 of 410 nm to the light transmittance T.sub.512 of 512 nm (T.sub.410/T.sub.512) is from 0.31 to 0.61, or a gadolinium oxysulfide sintered body in which the ratio of the diffraction peak intensity I.sub.y of a phase different from gadolinium oxysulfide appearing at 2=from 20 to 29 to the diffraction peak intensity (I.sub.x) of (102) or (011) of gadolinium oxysulfide appearing at 2=301 (I.sub.y/I.sub.x) is 0.1 or less in an XRD diffraction pattern and which contains one or more activators selected from the group consisting of praseodymium, terbium, and cerium.

A scintillator array comprises: a first scintillator element; a second scintillator element; and a reflector provided between the first and second scintillator elements and having a width of 80 gm or less therebetween. Each scintillator element includes a polycrystal containing a rare earth oxysulfide phosphor, the polycrystal having a radiation incident surface of 1 mm or less1 mm or less in area. An average crystal grain diameter of the polycrystal is not less than 5 m nor more than 30 m, the average crystal grain diameter being defined by an average intercept length of crystal grains in an observation image of the polycrystal with a scanning electron microscope. A maximum length or a maximum diameter of defects on the polycrystal is 40 m or less.

[Problem]

To provide a charged particle detection material which can detect charged particles due to a discharge phenomenon or the like caused even in a very low voltage which cannot be observed by a prior art, as well as a charged particle detection film and a charged particle detection liquid using the material.

[Solution]

The charged particle detection material and the charged particle detection film according to the present invention contain at least one of a fluorescent substance, a luminescent substance, an electroluminescent substance, a fractoluminescent substance, a photochromic substance, an afterglow substance, a photostimulated luminescent substance and a mechanoluminescent substance and can easily detect emission or incidence of charged particles in real time.