Resolution and Cathode Uniformity in Scintillation Counters

An investigation of photocathode uniformity using a pulsed light-source and a special type of source holder was carried out with a multichannel analyser. The sensitivity profiles of uniformity of the photocathode of a two-inch 14-stage photomultiplier at various focussing control voltages are presented in a number of contour maps. The variation of sensitivity along major and minor axes of the photocathode as a function of focus voltage has been investigated. An attempt is made to relate scintillation counter resolution to nonuniformity of the photocathode.