Resolution improvement using tapered fiber for a high resolution PET block detector

Tapered fiber optic plate (tapered fiber) is a fiber optic plate which input size and output size is different. One can magnify the light photon image by using the tapered fiber with low light loss. The tapered fiber may be a useful component for a high resolution positron emission tomograph (PET) block detector. Thus, investigations on resolution improvement were performed by using the tapered fiber on a PET block detector. The block detector consists of a scintillator block, a tapered fiber and a position sensitive photomultiplier tube (PSPMT). The light photon image of the scintillator block is magnified by tapered fiber which is optically coupled to the PSPMT. Light loss by using the tapered fiber was 27%. With the taper fiber, scintillator blocks consist of 11/spl times/11 matrix of 1.67 mm/spl times/1.67 mm/spl times/10 mm BGOs as well as 8/spl times/8 matrix of 2.0 mm/spl times/2.0 mm/spl times/10 mm were resolved in two dimensional distribution. It is concluded that tapered fiber is one solution for high resolution PET block detectors.