THE NUMERICAL COMPUTATION OF DEFLECTION FIELD OF THE DEFLECTION YOKE WITH WEDGE PROFILE AND THE ELECTROSTATIC DEFLECTOR WITH PLANAR ELECTRODES

This paper describes the computation methods of the deflection field of the deflection yoke with wedge profile and the electrostatic deflector with planar electrodes. The wedge yokes can be combined into various magnetic deflectors, which would offer a variety of choices for more effectively reducing the deflection aberrations by properly adjusting the deflection. field distribution. An advantage of the planar electrostatic deflector is its simplicity in structure. Thus it is probable that a deflector array for the multiple electron beam systems can be composed by the use of this kind of deflector. Based on the described methods in this paper, two practical computation programs have been worked out and, as examples, the field distributions of some typical deflectors have been computed.