Readout electronics for multianode photomultiplier tubes with pad matrix anode layout

A novel readout concept for multianode photomultiplier tubes with pad matrix anode layout

“…There are two known techniques which can be used in this case: 2-D charge division network (S. Cherry et al, US patent No: 5,719,400), or resistive matrix network proposed in Detector Group. This network provides a 2-D matrix output conversion into two 1-D (X, Y) projective outputs [1,2]. This circuit is shown in Fig.…”

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“…Weighted position readout circuits preprocess the 64 signals from the 8 x 8 anodes matrix which, in turn, are amplified without shaping and digitized using a charge integrating converter (A&D Precision, MA). This readout scheme, although in its current implementation suffers from the same detector dead-time limitation described in [20], implements a modified center of gravity (COG) calculation for the event positioning [7,[21][22][23][24], and integrates gain compensation for each individual anode.…”

“…Intrinsic resolution and spatial linearity of the detector were determined by scanning a 22 Na point source across its FOV on 0.3 mm steps. A twin detector was used to create a narrow photon beam by means of electronic collimation [16]; only LORs impinging perpendicularly on the crystals were accepted to create the individual crystal profiles.…”

A SPECT Scanner for Rodent Imaging Based on Small-Area Gamma Cameras

“…The photomultiplier have 12 stages of metal channel dynode and 8 8 multiple anodes, providing an active area of roughly . Each detector includes a compact PCB (Printed Circuit Board) stack directly attached to the PS-PMT sockets, containing a symmetric charge division circuit [24], [25]. Using this scheme the 64 anode signals of the PS-PMT are read out via a matrix of 128 resistors (one "X" and one "Y" per pad) arranged to allow the X and the Y signals from one tube to be represented by 8 signal lines for each dimension (8 X-channel x 8 Y-channel).…”