A Compact High Performance Readout Electronics Solution for H9500 Hamamatsu 256 Multianode Photomultiplier Tube for Application in Gamma Cameras

We have developed a new readout electronics module for 2-D data readout of H9500 256 (16 times16) Hamamatsu Photomultiplier Tube. This is a 3.04 times 3.04 mm
²
anode pad pitch size tube with 1.5 mm thick window. This photo tube is most suitable for high resolution gamma cameras, but the large number of anode outputs makes the readout electronics development complicated. The readout electronics solution to be presented is based on the resistors matrix network (V. Popov, US patent No: 6,747,263 B1) which provides decoupling of all 256 anode outputs into a set of 16 X + 16 Y analog outputs, plus it is integrated with anode gain non-uniformity correction circuit [Popov, et al., 2006], We chose this technique, because it allowed getting a maximum position accuracy performance and significantly reduced the number of analog data acquisition connections. The designed analog circuit uses only standard SMD components, no custom ICs. A small amount of analog outputs allowed to place all electronics components on a small size PCBs and to mount them directly on anode output connectors attached to H9500. This design preserves side-by-side uses of several H9500 PSPMT modules in arrays. We present the results of H9500 readout electronics evaluation in the case of uses of different scintillator pixillated crystal arrays and continuous scintillator crystal.