Beam focusing characteristics of the field emission arrays with parallel wedge emitter, gates and in-plane lens

A focusing structure of field emission arrays (FEAs) made of parallel wedge emitter, gate and in-plane lens is suggested in this paper. Using the particle-in-cell (PIC) simulation code MAGIC, the wedge emitter, parallel gate and anode with and without in-plane lens have been simulated. The electron beam streamlines and the x-p/sub y/ phase shows that the in-plane lens focuses the electron beam. For a typical model the beam width will be decrease to about 1/8 for every cell, and the transverse velocity will decrease from /spl plusmn/3.1/spl times/10/sup 6/ m/s to /spl plusmn/0.3/spl times/10/sup 6/ m/s while adding the in-plane lens.