Conceptual Design of Beam Tube of 300 KeV Electron Electrostatic Accelerator

The column of electron electrostatic accelerator is one of the critical components in electrostatic accelerator. The geometrical design of such accelerator must be as such that in the case of applying voltage to its electrodes, not only should its equipotential surfaces and its gradient accelerate the beam particles up to desired energy, but also it should focus the beam and hinder broadening of energy distribution of accelerated particles. The immersed electrodes in the field are, geometrically, perpendicular to optical axis around the medial plane. Numerous models that can be used in the distribution of axial potential, have been presented and linear model, analytical model, double-column electrode model and polynomial electrode model are among them. In this paper, series expansions based on Bessel functions is used to obtain the axial potential distribution of immersed accelerator electrodes in double-electrode field and it is then compared to the mentioned models by solving the final equation via the least square method. Finally, by using CST Studio software and the information we obtained from the axial potential, the column of electron accelerator with its energy distribution and its optimal electron output beam radius is designed and simulated.