Radioactive Tracer Study of a Photomultiplier Manufacturing Process

A quantitative measurement of the cesium disposition within a multiplier phototube was accomplished by the use of cesium-137 as a tracer. The processing and measurement techniques are described, and the significance of the findings are discussed in relation to tube performance and improvement. An attempt was made to examine the role of cesium in the fatigue behavior of the AgMgOCs dynode surface. The effort met with interpretation difficulties when it was found that an apparent excess of cesium masks the postulated surface changes. Experimental work with the Du Mont 6292 showed that a low fatigue rate is associated with a high degree of dynode oxidation, but no correlation with cesium uptake was readily evident.