Radiation Detector For Well-Logging Tool

Abstract

A radiation detector is used in a well-logging tool for positioning in a wellbore of a geologic formation. The radiation detector includes a photomultiplier housing and a scintillator housing. A housing coupler joins together opposing ends of the photomultiplier housing and scintillator housing. A photomultiplier is contained within the photomultiplier housing and a scintillator body is contained within the scintillator housing. A scintillator window is secured to the housing coupler.

1 - 20 . (canceled) 
     
     
         21 . A radiation detector system comprising:
 a photomultiplier component comprising:
 a photomultiplier housing; 
 a photomultiplier within the photomultiplier housing; and 
   a scintillator component comprising:
 a scintillator housing; 
 a scintillator body within the scintillator housing; and 
 a scintillator window secured to the scintillator housing; 
   wherein the photomultiplier housing and the scintillator housing are configured to connect to one another via:
 a fitting of an outer diameter of a first end of the photomultiplier housing into an inner diameter of a first end of the scintillator housing; 
 a fitting of an outer diameter of the first end of the scintillator housing into an inner diameter of the first end of the photomultiplier housing; or 
 a fitting of a housing coupler around the outer diameter of the first end of the photomultiplier housing and the outer diameter of the first end of the scintillator housing; or 
 any combination thereof. 
   
     
     
         22 . The radiation detector system of  claim 21 , wherein the photomultiplier component comprises a photomultiplier window secured to the photomultiplier housing. 
     
     
         23 . The radiation detector system of  claim 21 , wherein the photomultiplier housing and the scintillator housing are configured to connect to one another via the fitting of the housing coupler around the outer diameter of the first end of the photomultiplier housing and the outer diameter of the first end of the scintillator housing and wherein:
 the housing coupler defines an enlarged inner diameter relative to the scintillator housing; and   the scintillator window has a larger area than an adjacent portion of the scintillator body.   
     
     
         24 . The radiation detector system of  claim 21 , wherein the photomultiplier housing and the scintillator housing are configured to connect to one another via the fitting of the housing coupler around the outer diameter of the first end of the photomultiplier housing and the outer diameter of the first end of the scintillator housing and wherein:
 the scintillator window comprises a first material having a first coefficient of thermal expansion; and   the housing coupler comprises a second material having a second coefficient of thermal expansion that is within +/−20 percent of the first coefficient of thermal expansion.   
     
     
         25 . The radiation detector system of  claim 24 , wherein the first material comprises sapphire and the second material comprises a nickel-cobalt ferrous alloy. 
     
     
         26 . The radiation detector system of  claim 21 , wherein:
 the photomultiplier housing comprises a first material having a first coefficient of thermal expansion; and   the scintillator housing comprises a second material having a second coefficient of thermal expansion lower than the first coefficient of thermal expansion.   
     
     
         27 . The radiation detector system of  claim 26 , wherein the first material comprises stainless steel and the second material comprises titanium. 
     
     
         28 . The radiation detector system of  claim 21 , wherein the photomultiplier housing and the scintillator housing are configured to connect to one another via the fitting of the housing coupler around the outer diameter of the first end of the photomultiplier housing and the outer diameter of the first end of the scintillator housing and wherein the housing coupler defines respective overlapping joints with the photomultiplier housing and the scintillator housing. 
     
     
         29 . The radiation detector system of  claim 21 , wherein the photomultiplier housing has at least one vent opening therein and at least one plug associated with the at least one vent opening. 
     
     
         30 . A well-logging tool for positioning in a wellbore of a geologic formation comprising:
 a well-logging housing; and   a radiation detector within the well-logging housing, the radiation detector comprising:
 a photomultiplier housing; 
 a scintillator housing; 
 a housing coupler joining opposing ends of the photomultiplier housing and scintillator housing together via a fitting of the housing coupler around an outer diameter of a first end of the photomultiplier housing and an outer diameter of a first end of the scintillator housing; 
 a photomultiplier within said photomultiplier housing; 
 a scintillator body within said scintillator housing; 
 a scintillator window within said scintillator housing; and 
 a brazed joint securing said scintillator window and said housing coupler together; 
 wherein the scintillator window comprises a first material having a first coefficient of thermal expansion; and 
 wherein the housing coupler comprises a second material having a second coefficient of thermal expansion that is within +20 percent of the first coefficient of thermal expansion. 
   
     
     
         31 . The well-logging tool of  claim 30 , wherein the housing coupler defines an enlarged inner diameter in relation to the scintillator housing; and wherein the scintillator window has a larger area than an adjacent portion of the scintillator body. 
     
     
         32 . The well-logging tool of  claim 30 , wherein the first material comprises sapphire and the second material comprises a nickel-cobalt ferrous alloy. 
     
     
         33 . The well-logging tool of  claim 30 , wherein the photomultiplier housing comprises a third material having a third coefficient of thermal expansion; and wherein said scintillator housing comprises a fourth material having a fourth coefficient of thermal expansion lower than the third coefficient of thermal expansion. 
     
     
         34 . The well-logging tool of  claim 33 , wherein the third material comprises stainless steel and the fourth material comprises titanium. 
     
     
         35 . The well-logging tool of  claim 30 , wherein the housing coupler defines respective overlapping joints with the photomultiplier housing and the scintillator housing. 
     
     
         36 . A method for making a radiation detector for a well-logging tool, the method comprising:
 aligning opposing ends of a photomultiplier housing and a scintillator housing; and   joining the photomultiplier housing to the scintillator housing via:
 fitting an outer diameter of a first end of the photomultiplier housing into an inner diameter of a first end of the scintillator housing; 
 fitting an outer diameter of the first end of the scintillator housing into an inner diameter of the first end of the photomultiplier housing; or 
 fitting a housing coupler around the outer diameter of the first end of the photomultiplier housing and the outer diameter of the first end of the scintillator housing; or 
 any combination thereof. 
   
     
     
         37 . The method of  claim 36 , wherein joining the photomultiplier housing to the scintillator housing comprises threading, brazing, welding, or gluing, or performing some combination thereof, the photomultiplier housing to the scintillator housing. 
     
     
         38 . The method of  claim 36 , wherein joining the photomultiplier housing to the scintillator housing comprises threading, brazing, welding, or gluing, or performing some combination thereof, the housing coupler to the photomultiplier housing or the scintillator housing, or both. 
     
     
         39 . The method of  claim 36 , wherein joining the photomultiplier housing to the scintillator housing comprises hermetically sealing the scintillator. 
     
     
         40 . The method of  claim 36 , wherein joining the photomultiplier housing to the scintillator housing produces a joint with substantially contiguous exterior housing dimensions on both sides of the joint.