Neutron position-sensitive scintillation detector

Claim 1

An apparatus for mapping distributions of neutron positions in a scintillation detector comprising: a scintillator sensitive to neutrons while being insensitive to gamma rays, said scintillator having a polished face, a predetermined index of refraction, and a detection efficiency for thermal neutrons at least 1000 times greater than its detection efficiency for 1 Mev gamma rays, said scintillator emanating light flashes at points of neutron interactions therewithin; a plurality of photomultiplier means arranged to form an array and positioned to receive the light flashes of said scintillator, each of said photomultiplier means producing an output electronic signal proportional to the amount of light received by said photomultiplier means; light coupler means having an index of refraction approximately equal to said predetermined index of refraction of said scintillator, said light coupler means spacing said scintillator from said photomultiplier means; light concentrator means having an index of refraction lower than the indices of refraction of said scintillator and said light coupler means, disposed between and immediately adjacent said polished face of said scintillator and said light coupler means; said scintillator, said light concentrator means and said light coupler means cooperating so as to direct flashes of said scintillator on at least two photomultiplier means in any dimension mapped by said apparatus; said light coupler means dispersing the concentrated flashes of said light concentration means; position encoding electronic circuit means coupled to the electrical outputs of said plurality of photomultiplier tubes for producing position signals corresponding to coordinates of the position of each light flash; and means for interpolating said photomultiplier tube signals to determine the position of said light flash whereby the position of said neutron interaction in said scintillator is determined.

Claim 2

An apparatus for mapping distributions of neutron positions in a scintillation detector comprising: a scintillator sensitive to neutrons while being insensitive to gamma rays, said scintillator having a polished face, a predetermined index of refraction, and a detection efficiency for thermal neutrons at least 1000 times greater than its detection efficiency for 1 Mev gamma rays, said scintillator emanating light flashes at points of neutron interactions therewithin; a plurality of photomultiplier means arranged to form an array and positioned to receive the light flashes of said scintillator, each of said photomultiplier means producing an output electronic signal proportional to the amount of light received by said photomultiplier means; light coupler means having an index of refraction approximately equal to said predetermined index of refraction of said scintillator, said light coupler means spacing said scintillator from said photomultiplier means; light concentrator means having an index of refraction lower than the indices of refraction of said scintillator and said light coupler means, disposed between and immediately adjacent said polished face of said scintillator and said light coupler means; said scintillator, said light concentrator means and said light coupler means cooperating so as to direct flashes of said scintillator on at least two photomultiplier means in any dimension mapped by said apparatus; said light coupler means dispersing the concentrated flashes of said light concentration means; position encoding electronic circuit means coupled to the electrical outputs of said plurality of photomultiplier tubes for producing position signals corresponding to coordinates of the position of each light flash; and means for interpolating said photomultiplier tube signals to determine the position of said light flash whereby the position of said neutron interaction in said scintillator is determined.