The deflector plates are two parallel conductive plates that are used to drive the electron beams. A two-dimensional edge field of deflector plates with two grounded screens is considered. Using the methods of the theory of functions of a complex variable, an analytical expression for the potential of such a system is obtained. It is shown that the presence of grounded screens leads to the localization of the edge field in the region of the edges of the plates, the characteristic dimensions of which are on the order of the distance between the plates. The obtained expressions for the potentials take into account the influence of the edge fields on each other and make it possible to study the properties of a flat capacitor, the length of the plates of which is comparable to.

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