Photocathode Uniformity and Resolution of Scintillation Spectrometers

Abstract

Sixteen photomultiplier tubes have been studied to determine the relation between the uniformity of their photocathodes and the resolution obtained from a γ-ray scintillation spectrometer using each of them. The sensitivity contours of the tubes have been plotted. The resolution was found to be related to the average sensitivity but could be improved by concentrating the light on the most sensitive part of the photocathode. Techniques for studying sensitivity with an artificial light flasher are described.