An inverse design approach for magnetic lenses operated under infinite magnification condition

A theoretical-computational investigation has been carried out to describe a synthesis optimization procedure of asymmetrical magnetic lenses with the aid of numerical analysis methods. Where a certain mathematical form for the electron beam is proposed to be a target function. This function has several optimization parameters where the influence of each of them, when the other ones kept fixed, is investigated. Results have clearly shown that some of the optimization parameters have a considerable effect on the first order properties, third order aberrations and the reconstructed polepieces. While the others have no significant influence on these physical and geometrical properties. Furthermore, the results obviously show that there is an excellent ability for producing a conventional magnetic field for the double polepieces lenses.