Computational models for investigation of channel amplifier’s optimal parameters

Abstract

Microchannel electron multipliers, which amplify the input current of electrons through complicated stochastic processes, have found wide applications in different areas of science and engineering due to a number of remarkable properties. However, the loss of information caused by the statistical fluctuations in the gain of the channels, increases a noise factor which is a measure of the loss of available information. Investigations dealing with reducing of the noise factor are of considerable practical interest. The method, based on 3D Monte Carlo simulations and theorems about serial and parallel amplification stages, is used to show the dependence of the average gain and noise factor on the energy and the incidence angle of the input electron beam, and to find their optimal combination. The spread in incidence coordinates of the electrons of the input beam on the interior surface of a channel is taken into account in the model. The results are compared with a model where the incidence coordinate is same for all input electrons. The numerical experiments show that the spread in the collision coordinates of primary electrons significantly affects the average gain and the noise factor, and must be taken into account in theoretical models. The optimal combinations of the energy and the angle of the input electron beam, which provide the minimal noise factor and maximum gain, are obtained. Such investigations are effectively conducted using the method of serial and parallel amplification stages, and would be practically impossible using only direct simulations by the Monte Carlo methods.