Simplified dynamic model of electron source with a hot filament

摘要

In this paper a simplified dynamic model of a thermal electron source is considered. In this model the heat loss by the cathode is limited to radiation according to Stefan-Boltzmann law. A transfer function H(s) describing fluctuations of electron emission current ΔIe as a function of fluctuations ΔP of the power supplying a cathode of the source was fond. The transfer function depends on the cathode temperature and the frequency of variable component of the power. Error of the first order approximation is discussed in this paper. such a model can be used to design a filament supply with a negative feedback loop for controlling the magnitude of the electron beam.