Additive photomultiplier noise in the 10-3-10-1 Hz frequency range

Results of investigations into additive fluctuations of current of photomultiplers within 10-3-10-1Hz frequency range are given. Correlation and amplitude distributions of two type photomultiplier fluctuations for different ranges of the given interval of frequency are studied. Hypothesis of additive noise origination due to electron collection at dielectric surface inside the photomultiplier bulb due to charge drift along dielectric surface within the electrical field is introduced to explain the given data. Resulting current within the external circuit is a random value responsible for occurrence of additive fluctuations