Method for fabricating pixelated scintillators

Abstract

In a method of making pixelated scintillators, an amorphous scintillator material in a molten state is pressed into a plurality of cavities defined by a plurality of walls of a mesh array. The molten scintillator material in the plurality of cavities is cooled to form a pixelated scintillator array. An x-ray imager including a pixelated scintillator is also described.

What is claimed is: 
     
         1 . A method of making pixelated scintillators, comprising:
 providing a mesh array including a plurality of walls defining a plurality of cavities;   providing an amorphous scintillator material in a molten state;   introducing the amorphous scintillator material in the molten state into the plurality of cavities of the mesh array; and   cooling the amorphous scintillator material in the mesh array to form a pixelated scintillator array.   
     
     
         2 . The method of  claim 1 , wherein the introducing step comprises pouring the amorphous scintillator material in the molten state over the mesh array to allow it to flow into the plurality of cavities. 
     
     
         3 . The method of  claim 1 , wherein the introducing step comprises placing the amorphous scintillator material in the molten state over the mesh array and pressing it into the plurality of cavities. 
     
     
         4 . The method of  claim 1 , wherein the mesh array is constructed from a material having a thermal expansion coefficient substantially same as or smaller than a thermal expansion coefficient of the scintillator material. 
     
     
         5 . The method of  claim 4 , wherein the mesh array is constructed from a material having a melting temperature higher than a melting temperature of the scintillator material. 
     
     
         6 . The method of  claim 5 , wherein the mesh array is constructed from a material comprising a metal or metal alloy selected from the group consisting of cupronickel, Hastalloy C, Inconel, iridium, iron, Monel, molybdenum, steel, steel-carbon alloy, tantalum, thorium, titanium, tungsten, vanadium, and zirconium. 
     
     
         7 . The method of  claim 5 , wherein the mesh array is constructed from a material comprising a ceramic selected from the group consisting of HfB 2 , HfC, NfN, ZrB 2 , ZrC, ZrN, TiB 2 , TiC, TiN, TaB 2 , TaC, TaN, and SiC. 
     
     
         8 . The method of  claim 5 , wherein the mesh array is constructed from a material selected from the group consisting of graphite, silicon carbide, and boron nitride. 
     
     
         9 . The method of  claim 1 , wherein the plurality of walls of the mesh array are coated with a reflective layer. 
     
     
         10 . The method of  claim 9 , wherein the reflective layer has a color substantially matches a color of light emitted by the scintillator material. 
     
     
         11 . The method of  claim 9 , wherein the reflective layer comprises TiO 2 . 
     
     
         12 . The method of  claim 9 , wherein the reflective layer comprises a specular reflector selected from the group consisting of silver, gold, and aluminum. 
     
     
         13 . The method of  claim 1 , wherein the amorphous scintillator material comprises silicate or borate glass incorporated with terbium oxides. 
     
     
         14 . The method of  claim 1 , wherein the amorphous scintillator material comprises scintillating nanospheres having a size significantly less than a wavelength of light emitted by the scintillating nanospheres. 
     
     
         15 . The method of  claim 1 , wherein the scintillator material comprises poly vinyl toluene incorporated with a scintillating dopant material. 
     
     
         16 . The method of  claim 1 , wherein the plurality of cavities defined by the plurality of walls are arranged in a plurality of rows and a plurality of columns. 
     
     
         17 . The method of  claim 16 , wherein cavities in adjacent rows and/or columns are arranged staggered. 
     
     
         18 . The method of  claim 16 , wherein the plurality of cavities have a cross-sectional shape of a square, rectangle, circle, diamond, or hexagon. 
     
     
         19 . The method of  claim 16 , wherein the plurality of cavities define a pixel pitch ranging from 0.5 mm to 20 mm. 
     
     
         20 . A method of fabricating pixelated scintillators, comprising:
 forming a plurality of scintillator pixels from an amorphous scintillator material in a molten state;   applying a reflective layer on each of the plurality of scintillator pixels formed; and   assembling the plurality of scintillator pixels applied with the reflective layer to form a pixelated scintillator array.   
     
     
         21 . The method of  claim 20 , wherein the plurality of scintillator pixels are assembled by inserting them into a mesh array including a plurality of walls defining a plurality of cavities configured to receive the plurality of scintillator pixels. 
     
     
         22 . The method of  claim 21 , further comprising fixing the plurality of scintillator pixels in the mesh array using an adhesive in the plurality of cavities. 
     
     
         23 . The method of  claim 20 , wherein the plurality of scintillator pixels are assembled by binding them to each other using an adhesive. 
     
     
         24 . The method of  claim 20 , wherein each of the plurality of scintillator pixels has a first end portion and a second end portion, and the plurality of scintillator pixels are assembled through attachments to the first end portions of the plurality of scintillator pixels. 
     
     
         25 . The method of  claim 20 , wherein the plurality of scintillator pixels are formed from the amorphous scintillator material by a drawing technique. 
     
     
         26 . The method of  claim 20 , further comprising fire polishing the plurality of the scintillator pixels formed. 
     
     
         27 . The method of  claim 20 , wherein each of the plurality of scintillator pixels has a shape of a cylinder, a rectangular prism, or a square prism. 
     
     
         28 . The method of  claim 20 , wherein the amorphous scintillator material comprises silicate or borate glass incorporated with terbium oxides. 
     
     
         29 . The method of  claim 20 , wherein the amorphous scintillator material comprises scintillating nanospheres having a size significantly less than a wavelength of light emitted by the scintillating nanospheres. 
     
     
         30 . The method of  claim 20  wherein the amorphous scintillator material comprises poly vinyl toluene incorporated with a scintillating dopant material. 
     
     
         31 . The method of  claim 20 , wherein the reflective layer has a color substantially matches a color of light emitted by the scintillator material. 
     
     
         32 . The method of  claim 20 , wherein the reflective layer comprises TiO 2 , silver, gold, or aluminum. 
     
     
         33 . The method of  claim 20 , wherein the plurality of scintillator pixels are assembled in plural rows and plural columns. 
     
     
         34 . The method of  claim 33 , wherein scintillator pixels in adjacent rows and/or columns are arranged staggered. 
     
     
         35 . A pixelated scintillator array, comprising:
 a mesh array including a plurality of walls defining a plurality of cavities; and   a plurality of scintillator pixels in the plurality of cavities, wherein the plurality of scintillator pixels comprise an amorphous scintillator material.   
     
     
         36 . The pixelated scintillator array of  claim 35 , wherein the plurality of walls of the mesh array comprise a reflective coating. 
     
     
         37 . The pixelated scintillator array of  claim 35 , wherein the plurality of walls of the mesh array are constructed from a material having a melting temperature higher than a melting temperature of the amorphous scintillator material. 
     
     
         38 . The pixelated scintillator array of  claim 35 , wherein the plurality of walls of the mesh array are constructed from a material having a thermal expansion coefficient similar to or smaller than a thermal expansion coefficient of the scintillator material. 
     
     
         39 . The pixelated scintillator array of  claim 35 , wherein the plurality of walls of the mesh array are constructed from a metal or metal alloy. 
     
     
         40 . The pixelated scintillator array of  claim 39 , wherein the metal is aluminum. 
     
     
         41 . The pixelated scintillator array of  claim 35 , wherein the plurality of walls of the mesh array are constructed from a ceramic material. 
     
     
         42 . The pixelated scintillator array of  claim 35 , wherein the plurality of walls of the mesh array are constructed from a material selected from the group consisting of graphite, silicon carbide, and boron nitride. 
     
     
         43 . The pixelated scintillator array of  claim 35 , wherein each of the plurality of scintillator pixels comprises a reflective coating. 
     
     
         44 . The pixelated scintillator array of  claim 35 , wherein the plurality of scintillator pixels are arranged in plural rows and plural columns. 
     
     
         45 . The pixelated scintillator array of  claim 44 , wherein scintillator pixels in adjacent rows and/or adjacent columns are arranged staggered. 
     
     
         46 . The pixelated scintillator array of  claim 35 , wherein the amorphous scintillator material comprises silicate or borate glass incorporated with terbium oxides. 
     
     
         47 . The pixelated scintillator array of  claim 35 , wherein the amorphous scintillator material comprises scintillating nanospheres having a size significantly less than a wavelength of light emitted by the scintillating nanospheres. 
     
     
         48 . The pixelated scintillator array of  claim 35  wherein the scintillator material comprises poly vinyl toluene incorporated with a scintillating dopant material. 
     
     
         49 . An x-ray imager, comprising:
 a pixelated scintillator layer generating light photons from x-ray radiation; and   a detector array producing electrical signals from light photons,   wherein the pixelated scintillator layer comprising one or more scintillator arrays each comprising:
 a mesh array including a plurality of walls defining a plurality of cavities; and 
 a plurality of scintillator pixels in the plurality of cavities, wherein the plurality of scintillator pixels comprise an amorphous scintillator material. 
   
     
     
         50 . The x-ray imager of  claim 49 , wherein the plurality of walls of the mesh array comprise a reflective coating. 
     
     
         51 . The x-ray imager of  claim 49 , wherein each of the plurality of scintillator pixels comprises a reflective coating. 
     
     
         52 . The x-ray imager of  claim 49 , wherein the plurality of scintillator pixels are arranged in plural rows and plural columns, and scintillator pixels in adjacent rows and/or adjacent columns are staggered. 
     
     
         53 . A pixelated scintillator layer, comprising:
 a first pixelated scintillator array comprising a plurality of scintillator pixels arranged substantially in parallel in a first direction; and   a second pixelated scintillator array comprising a plurality of scintillator pixels arranged substantially in parallel in a second direction different from the first direction;   wherein the first and second pixelated scintillator arrays are arranged such that the first and second directions focus substantially at a source.   
     
     
         54 . The pixelated scintillator layer of  claim 53 , wherein
 the first pixelated scintillator array has a top surface proximal to the source and a bottom surface opposite to the top surface, the top and bottom surfaces of the first pixelated scintillator array being substantially parallel; and   the second pixelated scintillator array has a top surface proximal to the source and a bottom surface opposite to the top surface, the top and bottom surfaces of the second pixelated scintillator array being unparallel.   
     
     
         55 . The pixelated scintillator layer of  claim 53 , further comprising a plurality of the second pixelated scintillator arrays, the plurality of the second pixelated scintillator arrays and the first pixelated scintillator array forming a generally concave surface facing the source. 
     
     
         56 . The pixelated scintillator layer of  claim 53 , wherein
 the first pixelated scintillator array has a top surface proximal to the source and a bottom surface opposite to the top surface, the top and bottom surfaces of the first pixelated scintillator array being substantially parallel; and   the second pixelated scintillator array has a top surface proximal to the source and a bottom surface opposite to the top surface, the top and bottom surfaces of the second pixelated scintillator array being substantially parallel.   
     
     
         57 . The pixelated scintillator layer of  claim 53 , wherein the scintillator pixels of the first and second pixelated scintillator arrays comprise an amorphous scintillator material. 
     
     
         58 . The pixelated scintillator layer of  claim 53 , wherein the scintillator pixels of the first and second pixelated scintillator arrays comprise a crystalline scintillator material.