Beam Focusing Characteristics of the field emission arrays with parallel wedge emitter, gates and in-plan Lens

摘要

A focusing structure of field emission arrays (FEAs) made of parallel wedge emitter, gate and in-plan lens is suggested in this article. Using the particle-in-cell (PIC) simulation code MAGIC, the wedge emitter, parallel gate and anode with and without in-plan lens have been simulated. The electron beam streamlines and the x-p_y phase show that the in-plan lens focuses the electron beam. For a typical model the beam width will be decrease about to 1/8 for every cell, and the transverse velocity will decrease from +-3.1x10~6m/s to +- 0.3x10~6m/s while add the in-plan lens.