Radiation detector and a method of manufacturing the detector

Abstract

A scintillator array has a compact, two-dimensional arrangement of scintillators partitioned by light reflecting elements and light transmitting elements interposed between the scintillators. That is, the scintillator array has a lattice frame in the form of a crosswise combination of plate-like optical elements such as light reflecting elements and light transmitting elements. The lattice frame defines a plurality of cubicles. A transparent adhesive is poured into a rectangular vessel for receiving the lattice frame, the lattice frame is placed in the rectangular vessel, and then the scintillators are placed in the rectangular vessel. A cured resin object integrating the optical adhesive having cured, the lattice frame and the scintillators is removed from the vessel, and is contoured to make the scintillator array. In this way, the optical elements are arranged in the scintillator array without cutting them with a dicing saw or wire saw.

1 . A radiation detector having a scintillator array formed of a plurality of scintillators in a compact, two-dimensional arrangement, a light guide optically combined to said scintillator array, and a plurality of photomultiplier tubes smaller in number than said scintillators and optically combined to said light guide, wherein: 
 said scintillator array is formed of at least said scintillators and a lattice frame having plate-like optical elements combined crosswise, said lattice frame defining a plurality of cubicles.    
   
   
       2 . A radiation detector as defined in  claim 1 , wherein said optical elements are light transmitting elements interposed between said scintillators, said light transmitting elements being formed of positioning elements arranged at equal intervals at least on a plane of the scintillator array opposed to the light guide, and an optical adhesive for transmitting light, said positioning elements being positioning reflecting elements or positioning transparent films.  
   
   
       3 . A radiation detector as defined in  claim 2 , wherein said positioning elements have an overall total area at most a quarter of a total area of said light transmitting elements.  
   
   
       4 . A radiation detector as defined in  claim 3 , wherein the overall total area of said positioning elements is at most one tenth of the total area of said light transmitting elements.  
   
   
       5 . A radiation detector as defined in  claim 2 , wherein said positioning elements are arranged only on the plane of the scintillator array opposed to the light guide.  
   
   
       6 . A radiation detector as defined in  claim 2 , wherein said positioning elements are arranged also on a plane of the scintillator array remote from the light guide.  
   
   
       7 . A radiation detector as defined in  claim 2 , wherein said optical adhesive is a silicone adhesive.  
   
   
       8 . A radiation detector as defined in  claim 2 , wherein said optical adhesive is an epoxy adhesive.  
   
   
       9 . A method of manufacturing a radiation detector having a scintillator array formed of a plurality of scintillators in a compact, two-dimensional arrangement, a light guide optically combined to said scintillator array, and a plurality of photomultiplier tubes smaller in number than said scintillators and optically combined to said light guide, said method comprising: 
 (A) a step of fabricating a lattice frame by combining a plurality of plate-like optical elements crosswise;    (B) a step of pouring a transparent liquid resin into a rectangular vessel for receiving said lattice frame, before or after placing said lattice frame in said rectangular vessel;    (C) a step of placing the scintillators in the rectangular vessel after placing the lattice frame in the rectangular vessel and pouring said liquid resin into a rectangular vessel; and    (D) a step of removing from said rectangular vessel a cured resin object integrating the liquid resin having cured, the lattice frame and the scintillators, and contouring the resin object to make said scintillator array;    said steps (A)-(D) being executed to manufacture said scintillator array.    
   
   
       10 . A method of manufacturing a radiation detector as defined in  claim 9 , wherein a release agent is applied to said rectangular vessel before executing said step (B) of pouring the transparent liquid resin into the rectangular vessel.  
   
   
       11 . A method of manufacturing a radiation detector as defined in  claim 9 , wherein said liquid resin is defoamed when executing said step (B) of pouring the transparent liquid resin into the rectangular vessel.  
   
   
       12 . A method of manufacturing a radiation detector as defined in  claim 9 , wherein said rectangular vessel is formed of fluororesin.  
   
   
       13 . A method of manufacturing a radiation detector as defined in  claim 9 , wherein said rectangular vessel is formed of metal and has surfaces coated with fluororesin.  
   
   
       14 . A method of manufacturing a radiation detector as defined in  claim 13 , wherein said metal is aluminum.  
   
   
       15 . A method of manufacturing a radiation detector as defined in  claim 13 , wherein said metal is stainless steel.  
   
   
       16 . A method of manufacturing a radiation detector as defined in  claim 9 , wherein said optical elements used for fabricating said lattice frame are light transmitting elements, said light transmitting elements being formed of positioning elements arranged at equal intervals at least on a plane of the scintillator array opposed to the light guide, and an optical adhesive for transmitting light, said positioning elements being positioning reflecting elements or positioning transparent films.  
   
   
       17 . A method of manufacturing a radiation detector as defined in  claim 9 , wherein said optical adhesive is a silicone adhesive.  
   
   
       18 . A method of manufacturing a radiation detector as defined in  claim 9 , wherein said optical adhesive is an epoxy adhesive.