Studies of a solid detector array for high energy X-ray imaging system based on MA-PMT

This paper evaluated the possibility of using H65658(-10), a 4times4 multi-anode PMT (MA-PMT) assembly from Hamamatsu, to develop a solid state detector array for high energy X-ray imaging system. The whole detector system is assembled by several dozens of 32-channel detector modules, while each channel is consist of a CdWO 4 crystal read-out by a MA-PMT channel through a bunch of optical fiber. In the module, discrete CdWO 4 crystals and Mo spacers are arranged alternatively in a linear array and coupled to two H6568(-10) PMTs. Our studies have shown that most of PMT's specifications like noise, gain uniformity, crosstalk meet the system's requirements. But their linear ranges, which were limited by its saturation, are not wide enough for the imaging system which was originally proposed for solid detectors readout by photodiodes. And there is some potential to improve the detector's performance, like widen the linear range of the MA-PMT, extend the dynamic range of the imaging system beyond its linear range. We can also expect an improvement to the imaging system by reducing the X-ray source intensity, and get the benefit of easier radiation protection and eventually lower system cost