Obtaining doublet magnetic lenses by synthesis technique

Abstract

M*ethod commonly used for designed and investigated the doublet magnetic lens, is the analysis procedure. In the present work the synthesis procedure describe as a theoretical–computational study, has been put forward such a new tool to dealing with occasions for obtaining the triple magnetic lens. The method introduced here, prove the possibility of getting this types of lenses for a pre-assigned electron beam trajectory with a specific magnification condition, where the paraxial ray equation is used to specify this path. In general, this investigation depends comprises of three major steps. The first step aims at specifying the require axial magnetic field distribution, which contain two inflection points. In the second step the magnetic scalar potential corresponding to the specified field distributions in the previous step are calculated. The third and final step is mainly concerned with the reconstructed the triple polepiece profiles that produce a magnetic field distributions in the first step. The three above steps have been applied at infinite magnification condition, and through our use the paraxial-ray equation and some of the optimization parameters related with the electrons beam path. Some of these parameters have been studied individually to see the effect on the access to triple lenses by synthesis. The results appear that, the synthesis procedure can be used as an excellent tool to producing and optimizing triple magnetic lenses.