Patent ID: 7238943

Claim:
An apparatus, comprising: a plurality of photomultiplier tubes; and a scintillation crystal array coupled to the plurality of photomultiplier tubes, the scintillation crystal array defining a plurality of corners; wherein a first corner of the plurality of corners is aligned with a first center of a first photomultiplier tube of the plurality of photomultiplier tubes and a second corner of the plurality of corners is not aligned with a second center of a second photomultiplier tube of the plurality of photomultiplier tubes; wherein the scintillation crystal array comprises a pentagonal block of crystals; and wherein the pentagonal block is tapered in accordance with the following equation: T=W /cos 2 (180° /N )−2 D tan(180° /N ) where T is a taper amount, W is a width of the scintillation crystal array, D is a depth of the scintillation crystal array, and N is a number.