Photon address digital detector system (PADDS): a cost-effective imaging photon detector.

We describe the implementation of an imaging photon detector for the photon address digital detector system (PADDS). The concept is based on combining an image intensifier with a position-sensitive photomultiplier tube with crossed-wire anodes. Particular emphasis is placed on modularity and flexibility. A digital signal processor evaluates events in real time. The compact detector system is able to process photon events with high precision in time with only moderate computing power of the host system. Laboratory experiments show the feasibility of the approach presented for observing rapidly varying sources at low light levels.