Simulations of emission characteristics of a multi-gated single carbon nanotube field emitter

In this paper, a two-dimensional, particle-in-cell computer simulation code MAGIC was used to investigate the field emission characteristics from a single closed-capped multi-walled carbon nanotube (MWCNT) in various multi-gated focusing configurations. The schematic diagram of the simulated quadrupole-gated focusing configuration was also presented. The field emission current and beam spot radius were measured as a function of the voltage on the third gate. Also, the potential distribution of the quadrupole-gated focusing structure with a cathode voltage of 0 V, 84 V of the first gate, 222 V of the second gate and 1320 V of the third, and the fourth gate and the anode was shown. The emission current density focused at 1320 V on the third gate was also presented.