Radiation detector

In a radiation detector comprising a larger plural number of mutually adjacent scintillators arranged closely together in a two-dimensional matrix formation with at least six rows and at least six columns and a smaller plural number of photomultiplier tubes optically connected to said scintillators, the improvement wherein mutually adjacent pairs of said scintillators are in direct face-to-face contact with each other over specified regions on mutually opposite surfaces, indentations are formed at a plurality of specified other mutually separated regions distributed evenly throughout on the mutually opposite surfaces of mutually adjacent pairs of said scintillators, said indentations are completely filled with an optically reflective material comprising barium sulfate powder mixed with a binder of synthetic resin, no air gap is left between mutually adjacent pairs of said scintillators, and the total of areas between a mutually adjacent pair of scintillators covered by said reflective material varies according to the order in which said scintillators are arranged, increasing monotonically from central to peripheral positions in said matrix.

In a radiation detector comprising a larger plural number of scintillators arranged closely together in a two-dimensional matrix formation with rows and columns and a smaller plural number of photomultiplier tubes optically connected to said scintillators, the improvement wherein an optically reflective material comprising barium sulfate powder mixed with a binder of synthetic resin is deposited directly upon and firmly attached to a plurality of specified mutually separated regions distributed evenly throughout on mutually opposite boundary surfaces of said scintillators and the total of areas on each of said boundary surfaces covered by said reflective material varies according to the order in which said scintillators are arranged, increasing monotonically from central to peripheral positions of said matrix.