Statistical behaviour of the scintillation counter: Experimental results

We have done an experimental test of a theory of the scintillation detector's statistical properties. Mean and amplitude variance of the output current pulse following γ-rays excitation, have been calculated and measured. We have taken into account the case of non-Poissonian photoelectron distribution and considered the effect on the mean and variance of the output current pulse of amplitude selection of the charge pulses from the scintillation detector. To test the theory, we have measured: the equivalent illumination, the single electron response, the gain of the electronmultiplier and its variance, the mean and variance of the selected output charge distribution. From these measurements, mean and variance of the output current pulse as a function of time have been calculated and compared with the same quantities measured directly. The good agreement between theoretical and experimental results support our theoretical model for the behaviour of the scintillation counter. We can conclude that to describe the statistical behaviour of the scintillation counter it is sufficient to know the following parameters: equivalent illumination, single electron response, gain of the electronmultiplier and its variance, mean and variance of the selected output spectrum.