Excess noise of secondary emission in the frequency range of (10-3 - 10-1) Hz

Study of excess current fluctuations of photomultipliers in the (10-3 - 10-1) Hz frequency range was conducted. Spectral density and amplitude distribution of current fluctuations in the photomultipliers of two types for several intervals of the frequency range considered were measured. To fit the experimental data the hypothesis of excess noise appearence in photomultipliers was proposed. This hypothesis considers the effect of electron storage on the inner dielectric surface of photomultiplier tube with sequential electric potential from change resulting from charge transfer along the dielectric surface in the external electric field. The current which appeared in the outer circuit as a result of this charge transfer is a random value responsible for the exess fluctuations apperance. 9 refs.; 5 figs.; 2 tabs