On the voltage distributions for philips 56 and 58 AVP photomultipliers

Two standard voltage distributions, differing from those recommended by the manufactures, to be used for Philips 56 and 58 AVP photomultipliers in conditions of high gain or of high linearity have been determined. Measurements are given in which there is considerable improvement in gain or in linearity obtained with such distributions as compared with those recommended by the manufacturers. A new apparatus for independently varying the interdynode voltages is described, with which the optimum distributions for any particular photomultiplier can be easily found.