Synthesis of Asymmetrical Charged Particle Lens Using Analytical Potential Model

Abstract

Abstract In the present work, the optimization by synthesis approach in the field of charged particle optics has been followed, where a modified analytical function has been proposed to represent the axial magnetic scalar potential distribution of the charged particle lens. Thereby, the corresponding axial field distribution can be deduced which is necessary to determine the paraxial ray trajectories and the aberration coefficients. Indeed, the present work deals with asymmetrical distributions of the lens field, accordingly, the first order properties and third order aberrations of the charged particle lens have been evaluated under zero and infinite magnification modes taken into account the effect of some geometrical parameters. The present work aims to reconstruct the shape of the pole piece of the magnetic lens that produced the proposed target function. The results have shown that, the pole piece shape of the lens and the field distributions have new irregular configurations as well as the objective properties of the lens are of acceptable values, according to the constraints that are imposed in the design process.