L.B. Rozenfeld
Research Institute for Electron & Ion Optics, Moscow, Russia
The problems of construction of dynamic focusing system for electron beam (or ion beam) technological devices, providing constant value of beam diameter on all scanning field on the object, are discussed. Analytical expressions for calculation such systems are proposed. It is shown, that for providing constant value of magnification at big angles of beam deflection it is necessary to use (as a minimum) three dynamic lenses.
