The Quadrant Photomultiplier

A unique photomultiplier tube has been designed, fabricated and studied. The quadrant tube has four transmission-mode K2CsSb (bialkali) photocathodes in a single 81mm square glass envelope. A novel electron multiplier structure with four independent anodes supplies secondary emission gains of 105 or more. Detailed measurements indicate that the tube performs like four individual photomultipliers. Data are presented on crosstalk, energy resolution, linearity and spatial uniformity. The use of the tube in Anger scintillation cameras and other applications requiring high detection efficiency, position-sensitive photomultipliers is discussed.