Wien filters as high energy resolution monochromator and analyzer

Abstract

Wien filter has been described from its born to the present time and consider why it cannot be main analytical equipments. In recent years, most of the drawbacks of the Wien filter have been overcome and it becomes a best analytical instrument for electrons. Three different designs of multi-pole Wien filters are proposed and describe those merits and demerits. Lastly, retarding technique using Butler electrodes has been demonstrated to improve the energy resolution.